3 Periods of the Stone Age: Paleolithic - Mesolithic - Neolithic

The study of the evolution of human race on this planet, which has almost nine million different species of animal and plant life to date, is divided into two great periods: Prehistoric and Historic. The Prehistoric period studies the appearance of the first hominids or ancestors of man and his evolutionary process from 5 million years ago until the invention of writing in 4 000 B.C., when man began to transmit news about himself, reporting his existence. Here the Prehistoric period ends and the Historic Period begins to this day.

This first stage in the evolution of mankind, which is substantially longer than the second, is further subdivided into two stages according to man’s relationship with his environment and with the materials he used. Therefore, we have the Stone Age, during which Man fundamentally used stone to fabricate the tools he needed in his daily life, and the Metal Age, when humans learned, with the help of fire, to fuse some minerals to transform them into metals, and later use them as tools.

The Origin of Life
After so many years of development, advances in science and technology, the origin of life remains a mystery that continues to challenge and baffle scientists. The “big bang” of biology, a definitive and irrefutable theory on the origin of life that is accepted by all, has yet to be discovered. No one has so far managed to recreate the real conditions of primitive Earth when life first appeared; that is to say, no one has been able to turn back the clock and recreate the conditions that favored the transition of inorganic nonliving matter into organic living matter.

The recreation in laboratory of environments that could be similar to that of primitive Earth did not result in the appearance of life form. The old Aristotelian derived theory of spontaneous generation harbored by some, that fully-formed complex living organisms could arise naturally and spontaneously from nonliving matter, has long been put to death once and for all by Louis Pasteur in the nineteenth century with his famous swan-neck flask experiment, from which he concluded that “life only comes from life”.

“The most complex machine man has devised – say, an electronic brain – is child’s play compared with the simplest of living organisms,” wrote American biologist and Nobel Prize winner in Medicine, George Wald. “The especially trying thing is that complexity here involves such small dimensions. It is on the molecular level; it consists of a detailed fitting of molecule to molecule such as no chemist can attempt.”

We know that the force of gravity was responsible for the agglutination of matter and space dust, and the formation of planets and stars. It is unknown if there is an analogous force in biology that causes different organic molecules to come together to form a prokaryotic cell.

To date, all that biology has been able to establish is that, under very peculiar conditions, inorganic molecules can be transformed into organic molecules, but the transition from these simple organic molecules like amino acids to something that is complex enough that it can self-replicate, and endowed with metabolism, remains a great mystery. It is known, however, that the microorganisms at that period used methane or hydrogen for metabolism instead of oxygen: they were organisms with anaerobic metabolism. Fermentation is a modern example of this type of metabolism.

Long before photosynthesis, and the eukaryotic cells that perform it, the first living beings on our planet would have the aspect of single-celled microorganisms or prokaryotic cells, like today’s bacteria and archaea, and would have lived in extreme environments, next to thermal springs in the primitive seas, nourishing themselves from the reactions between inorganic substances. From these first living beings, those capable of carrying out fermentation emerged, later the photosynthetic and, lastly, the heterotrophic beings, that is, living beings that, unlike plants, are not able to produce their own food.

The Evolution of Species
Then God said, “Let the earth put forth vegetation: plants yielding seed, and fruit trees of every kind on earth that bear fruit with the seed in it.” (…) And God said, “Let the waters bring forth swarms of living creatures, and let birds fly above the earth across the dome of the sky.” (…) And God said, “Let the earth bring forth living creatures of every kind: cattle and creeping things and wild animals of the earth of every kind.” And it was so. Genesis 1:11, 20, 24

The theory of evolution of species that Charles Darwin published in 1858 is the result of empirical research conducted during his voyage to the Galapagos Islands, which led him to conclude that life on this planet comes from a common stock, that is, that all living beings on this planet, both plants and animals, are related. All individuals have common ancestors.

The diversification of living beings or the evolution of species occurs by adaptation to the environment and natural selection – the better equipped, the strongest, prevail over the weakest or, as the proverb says, “the weak do not recite history”. Those that best adapt to the environment will eliminate their rivals and manage to pass on their genes to the next generation because the females instinctively allow themselves to be fertilized by the strong and reject the weak.

The first living beings appeared 3.5 billion years ago and one billion years later, the first photosynthetic living beings appeared, followed by the eukaryotes soon after. Around 543 million years ago, there was a period of great explosion of evolutionary changes in life form on this planet known as the Cambrian Period; there are many fossils that document this phase of life on Earth.

The first living beings were the microscopic organisms, primitive plants and invertebrates (worms and arthropods). Fish were the first vertebrates to emerge. It was 570 million years ago that plants invaded the dry land from the sea. Some animals had already done so before, but they did not stay on dry land permanently, because there was no food available there.

Animals came on dry land periodically, but remained most of the time in the sea: these were the amphibians. About 438 million years ago, they began to increase their time on land and 30 million years later, they evolved into reptiles. From the reptiles, evolution took two different paths: some reptiles evolved into mammals and others into birds.

Around 360 million years ago, the dinosaurs reigned on our planet. Some time later, the mammals which already coexisted with the dinosaurs but were insignificant began to stand out. About 245 million years ago, the dinosaurs became extinct and the mammals increased in number due to the absence of predators. About 66 million years ago, the primates appeared. Then 55 million years ago, the common ancestor of the pongids and hominids evolved. The earliest hominids emerged 8 million years ago.

Ontogenesis and Phylogenesis
Ontogenesis recapitulates phylogenesis by postulating that there is a similarity between the aspect of the embryonic stages of the human fetus, from conception to birth, and the development of the different life forms, from the unicellular origin to the human being. It is a discarded theory today, but it is close to the analogy that is often established between different fields of knowledge.

From the conception of an individual to his birth, the evolution of life on Earth is recapitulated, from the single-celled origin to the complexity of a human being. The diverse forms that the embryo acquires in its development resemble, in some way, the forms that life has assumed in the evolution of the species, from the prokaryotic archaea to the human being.
 
Furthermore, after birth, the development of an infant to self-awareness, that is, until he realizes that he exists as a person and begins to communicate, he recapitulates the evolution of the human race from the last primate that was not yet bipedal and did not speak to the Homo sapiens who stand erect walking upright and have the ability to communicate.

The Evolution of Human Life
For these reasons the Teaching Authority of the Church does not forbid that, in conformity with the present state of human sciences and sacred theology, research and discussions, on the part of men experienced in both fields, take place with regard to the doctrine of evolution, in as far as it inquires into the origin of the human body as coming from pre-existent and living matter - for the Catholic faith obliges us to hold that souls are immediately created by God. Humani Generis, 36 – Pope Pius XII, 1950
   
“There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” Charles Darwin, The Origin of Species, 1858

Charles Darwin never said that humans evolved from the present day monkeys. According to the British naturalist, humans, monkeys, chimpanzees and gorillas, all have a series of common ancestors. These ancestors lived on the African continent about 6 and 5 million years ago. Scientists named this species the Sahelanthropus tchadensis.

After this, between 5 and 3.5 million years, the Australopithecus afarensis emerged. Lucy, found in Ethiopia, belongs to this family, which marks the moment when the human race learned to walk. A little later, 2.6 million years ago, the first human tools appeared. Following this, 2.5 million years ago, the Homo habilis appeared, so called for the use he made of the tools.

The mastering of fire took place 1.5 million years ago; food began to be cooked about one million years later, and 400 thousand years ago, Homo neanderthalensis left Africa to inhabit the western part of Eurasia. The Homo sapiens remained in Africa. Then 350 thousand years ago, the Neanderthals developed and occupied Eurasia, from Portugal to Siberia.

About 100 thousand years ago, the Homo sapiens left Africa and appeared in Israel. Five thousand year later, they arrived in Malaysia, and 55 thousand years after that, in Australia. At that same time, they invaded Europe, defeating the Neanderthals or interbreeding with them. About 28 thousand years ago, we have the last evidence of the Neanderthals who became extinct. Fourteen thousand years ago, the Homo sapiens passed from Siberia through the Bering Strait and entered America through Alaska, gradually moving south, until they occupied the entire continent.

The Paleolithic or the Old Stone Age (2.5 million BC – 10 000 BC)
In this era, human beings were nomadic and did not build permanent dwellings. Because of this, they lived in caves, and had to compete with wild animals for this type of habitat. When food in that region was used up, families had to migrate to another region.

They lived by hunting small, medium and large animals, fishing and gathering fruits, leaves and roots. The economy during the Paleolithic phase was subsistence, that is to say, the group did not amass or produce for trade, but only for their own survival.

This period is also known as the age of chipped-stone tools. The first humans, who mastered and knapped stones, had the practice of producing materials by taking two stones and hitting them together to generate sharp points. These artifacts served, especially, for cutting meats and animal skins. They used instruments and tools made from pieces of bones and stones (axes, spears, staves, knives etc.). The goods produced were for collective use and property.

The Discovery of Fire
One of the greatest discoveries of this period was the production of fire through two processes. The most rudimentary was the friction of two stones over a pile of dry straws. The sparks produced ignited the straws.

In a second more elaborate procedure, a small stick was turned in a hole made in a piece of dry wood. This method, through friction, generated heat that passed to the straw, creating the fire.

• As we have commented in another text, fire had a great importance for the cohesion of families and communities, because everyone gathered around the fire for warmth. Since no one wanted to be left out in the cold, fire acted as a deterrent to antisocial attitudes.
• It allowed the light of the day to extend into the night, and because it was impossible to work at night, the two or three hours of tenuous light served for cultural events, to share experiences and for the handing down of culture from parents to children.
• The light in the night promoted safety of human beings in relation to animals that hunted at night, as it served to scare them away.
• However, the most important use of fire at that time was in the preparation of food. Cooked or roasted food has improved human diet. Certain foods are more nutritious cooked than raw. Fire and cooking of food are responsible for population growth and human survival.
• Finally, it was precisely fire that allowed humans to move from the Stone Age to the Metal Age.

The Social Organization
The men organized themselves in small groups, where the leader was the strongest and the most skilled. The men had the task of hunting, fishing and protecting the group. The women had the job of preparing food and caring for the children.

Communication
The communication in this period was based on the emission of some sounds (noises), without the elaboration of words, and physical gestures. Another widely used form of communication was cave paintings (drawings made on cave walls). Through these drawings (cave paintings) men marked time, exchanged experiences and transmitted messages and feelings.

Rituals
In the Paleolithic, men already performed funeral rituals. Archaeologists have found, in various regions, ceramic pots with human remains and personal objects inside caves. Religious rituals were also performed with the use of fire.

Hominids that lived in the Paleolithic Period
Australopithecines, Homo habilis, Homo erectus, Neanderthal Man or Homo neanderthalensis, Homo sapiens and Cro-Magnon Man, the earliest known European.

The Mesolithic or the Middle Stone Age (10 000 BC – 8 000 BC)
The Mesolithic is an intermediate period of the Prehistory, between the Paleolithic and Neolithic periods. This phase did not occur in all the regions of the world, but only in those where glaciation or the ice age had the most considerable effects.

In this intermediate period, the human being became more related to nature and began to make the first experiences of its domination. The nomadic lifestyle and dependence on external food did not allow development. Man learned to domesticate animals rather than hunt them, thus always having food at his disposal. On the other hand, instead of gathering fruits, plants and roots, he began to cultivate them. In this way, he managed to maintain a certain independence from the environment.

According to these regions, many humans maintained a life similar to that of the Paleolithic, depending on whether they were more dedicated to the domestication of animals or the cultivation of crops. The shepherds would be nomadic, for they followed their herds to pasture, while the farmers settled on the most fertile lands near the rivers.

The Neolithic or the New Stone Age (8 000 BC – 4 000 BC)
The Neolithic is also known as the New Stone Age. The beginning of this period is marked by the end of the ice age, a period when almost the entire planet was covered in ice, and ended with development of writing in Sumer in the Mesopotamia region.

The development of agriculture has allowed human beings to have a life less dependent on nature. With this advancement, they no longer needed to gather wild fruits, vegetables and roots, although these activities continued to be practiced.

The domestication of animals (goats, oxen, pigs, horses and birds) also contributed to the improvement in the quality of life. Together with agriculture, the domestication of animals allowed man to significantly increase the amount of food produced, eliminating the dependence on hunting.

As a result of the development in agriculture and the domestication of animals, humans ceased to be nomadic (with no fixed address) to become sedentary (with fixed address). This fact enabled the development of the first communities (tribes, villages, towns and cities). These first communities developed along the banks of rivers and lakes. In addition to meeting basic needs, water took on a new role in human life: the irrigation of crops.

With the increase in food production, the need for storage was created. In the Neolithic period, there was a great development of ceramic art. Vessels and pots were shaped and fired. According to archaeologists, the first ceramic objects were made around 8,500 years ago.

In the first communities that were formed, it became necessary to organize the work. The men were in charge of hunting, fishing and safety of the community (military protection function). The women were left with the tasks of caring for their children, agriculture and food preparation.

With the increase in production came the surplus. In addition to storing for periods of greatest need, men began to exchange these products with other communities. This was the beginning of trade economy.

With more food, there was a significant increase in population. This fact led to the need for more advanced forms of administration, including the establishment of more specific leadership and task allocation within the community.

In the Neolithic, men began to build more resilient dwellings because they needed to remain in fixed locations. Houses of wood, clay and blocks of stone were built in the villages. On the banks of rivers and lakes, stilts were more common (wooden houses with stakes fixed at the bottom of the river or lake).

The first civilizations arose and developed in the Neolithic period. Among them, we can mention: the Mesopotamian civilization (between the Tigris and Euphrates rivers) and the Egyptian civilization (along the banks of River Nile, northeastern Africa).

Conclusion: Unlike animals that have always lived at ease in a symbiotic relationship with Nature, survival and development for humans required an emancipation from it. The use of instruments, made of stone was the first act towards freedom.

Fr. Jorge Amaro, IMC

3 Metabolism Factors - Fuel - Oxidizer - Ignition

After writing about photosynthesis as the process by which plants transform energy into matter, we now address the reverse process: the transformation of matter into energy. Plants burn part of the matter they produce in order to survive and they do so in the same way as other non-vegetative living things. The only difference is that plants only burn what they themselves produce – they are therefore completely independent, while other living beings burn what plants produce because they cannot produce their own food.

In this sense, we are talking about metabolism, which is in fact, a slow controlled combustion reaction where there is an ignition – the moment when the living being is born and begins to inhale oxygen which is the oxidizer for all combustion – and a fuel, the food consumed by each living being. Before we talk about this slow combustion that takes place inside each living thing, let us talk about combustion in general.

The Process of Combustion
Combustion is a chemical reaction between two substances: a fuel and an oxidizing agent, that is, something that facilitates or makes the combustion possible. The oxidizer is always oxygen, and all fuels have something in common: they are of organic origin, that is, they were once living organisms with carbon chains linked to hydrogen or oxygen atoms.

If this is the case then how does our star, the sun, carry out combustion where there is no oxygen and no organic matter? Combustion on Earth is a chemical reaction. Inside the sun and all the stars, combustion is a nuclear reaction; in other words, the pressure inside the sun is so immense that energy is released by nuclear fusion of hydrogen nuclei into helium. 

Back to our reality on Earth, for a combustion reaction to take place, it is not enough to just have a fuel; we need an oxidizer to help in the process or to make it possible. Take a lighted candle, for example – it can burn for hours until all the wax is burned off; but if we put it under a glass dome, it will continue to burn only until all the oxygen is used up. Without the oxidizer and still with a lot of fuel, the flame will nevertheless go out.

In addition to the fuel and the oxidizer, there is still a third component that is essential for combustion: the ignition. The candle does not come lit, someone has lit it; even in the presence of oxygen, the candle would not burn if it isn’t first ignited. Even gasoline, which is far more flammable than a candle, does not burn in the presence of oxygen unless it is ignited. In the case of gasoline, the ignition may even be the heat in the air.

Let us recall that in the second stage of photosynthesis, carbon dioxide is combined with hydrogen to form matter. In combustion, that matter is oxidized, that is, it is combined with oxygen O2 to form carbon dioxide CO2 and water, releasing energy or heat in the process. The energy that is released, shall we say, is the very energy that a plant had previously obtained from the sun and has been amassed in the fossil fuel, be it coal, wood, oil or natural gas.

The Fuel
This is any substance that reacts with oxygen in the air, releasing light and heat. In this way, fire is the process by which matter releases its energy or becomes energy. Whatever the substance, it is always the result of a past photosynthesis. Fuel is amassed or stored up energy, it is matter that can transform into energy, back into something it once was. All it needs is a start, a starter engine, and the presence of an oxidizer which is oxygen.

For much of human history, fuels were from plants, alcohol, vegetable oils such as castor oil, and animal fats. During the first industrial revolution, the first fossil fuel came into use – mineral coal – which for a long time had fed the first man-built engine: the steam engine.

Then came petroleum and its derivatives, diesel, kerosene, and gasoline; also natural gas, first for domestic use, later for industrial use. Finally, nuclear energy emerged, resulted from the fission of uranium atoms, releasing energy that is then harnessed by the principle of the steam engine to move electric generators.

The Oxidizer
We have said that most of the fuels are of organic origin. The same can be said of the oxidizing agent, oxygen. As we have seen in speaking about photosynthesis, oxygen is a component of water; there is no free oxygen in space; what little there is, it is part of the water molecule and exists in space as ice. The same thing happens on Earth: oxygen is in the water and the water is in the sea.

In order to release oxygen from water, we need a source of energy to break water molecules by the process of electrolysis. However, this process does not happen in nature – the natural process from which oxygen is released is by photolysis which occurs in the first stage of this process.

It is plants, both terrestrial and aquatic, that release oxygen into the air when they photosynthesize. If our air is currently composed of 21% oxygen which allows and facilitates all the combustion taking place on our planet, both the active ones without as well as the slow ones within all living beings including plants, we owe it all to the cyanobacteria that have been making oxygen at the bottom of the oceans for millions of years, bubble after bubble, with the help of the sun.

The Ignition
Like we have said earlier, a fuel in the presence of the oxidizer does not burn if it is not ignited. There must be a kick-start. Even our universe needed a starter, and its kick-start was the Big Bang. All combustion reactions need to be started; after that everything progresses automatically. Like the domino tiles placed upright one after the other, the tiles will not fall sequentially without a tipping force on the first tile to initiate the chain reaction.

Ignition can be defined as the minimum temperature at which a fuel begins to burn incessantly. In the early days of mankind, when fire was first discovered, ignition was triggered by the friction between two sticks of wood until a spark occurred. Today all combustion reactions are initiated by an electrical spark or a match. Gasoline engines need a spark to initiate the chain reaction; in diesel engines, the diesel is heated and compressed until it explodes on its own.

The Discovery of Fire
Fire is an active combustion in which and by which substances called fuels are combined with oxygen in the air, producing light, heat and carbon dioxide. The technically correct definition, however, does not fully satisfy our amazement and willingness to understand it. We can’t help but be intrigued with this reality. As if by magical arts, it seems to be present everywhere; when invoked or summoned, it becomes visible and cannot be ignored because it burns, destroys, warms, modifies, melts, and then disappears. Nothing remains as it was, it destroys some realities and creates others, before disappearing again and becoming invisible until summoned or invoked again. Fire and its true nature have always intrigued the human beings. Let us see how the Greek mythology treated this reality.

Prometheus Stole the Fire from the gods
In the Greek mythology, it was the Titan Prometheus, with the condescension of Zeus, who created human beings that should have been obedient to the gods. Always benevolent to his creatures, Prometheus climbed Mount Olympus to steal the fire from the gods in order to provide the humans with the best weapon to master nature.

The human civilization progressed rapidly after that, and this displeased Zeus greatly who punished Prometheus by having him chained to a rock. Every day an eagle sent by Zeus came to eat the Titan’s liver, which re-grew every night only to be eaten again by the eagle on the following day. Despite his agony, Prometheus never repented of his rebellious act and was eventually freed from his torment many years later by the demigod, Hercules who was renowned for his strength.

In this myth, Prometheus is exalted for his intelligence, and more important than strength, for his altruism as the benefactor of humanity, for the risk he took and that despite so much suffering, he did not regret what he did for humanity. The progress of mankind is owed to the fact that man is as creative as God. But even with his creativity, he needed fire in order to truly master nature; with fire, man can blend the existing elements and create new ones. Without fire, he would remain in the darkness of ignorance.

It is impossible not to see in Prometheus certain similarities with Christ of the Christian religion. He represents great resources, notably his remarkable intelligence and prudence, but he also follows the idea of rebellion against established power, the liberation of the oppressed, the sacrifice of self without counting the cost, and finally the creation of a new system to which all have access: the Kingdom of God.

The Fireplace
Fire has not only allowed us to associate and mix elements of different nature, like the fusing of metals and the invention of new stronger alloys, but it has also attracted human beings to gather around it and form communities. The need to stay warm, not to die of cold by being excluded from the fire or from the community, led humans to overcome individualism and to create cohesive communities.

This is the reason why the fireplace evokes in us the fraternal feelings of harmony, peace and love; until very recently, the families of a village were counted by fires: the number of fires of a village was the number of families in the village.

Even today, love is symbolically represented as a fire in countless poems. There is a sonnet by the Portuguese poet Camões that attests to this use of fire as a symbol of love: “Love is a fire that burns yet burns unseen.” In fact, love unites two different people, creates bond, conquer individualism, creates equality between people, and creates alliances, harmony, and fraternal coexistence.

For thousands of years, around the campfire, culture circulated and were handed down by oral tradition: grandparents passed on to their children and grandchildren what they themselves had received from their own parents… Winters were long and longer still were the nights; during the day there was no time for coexistence as it was necessary to fight for life. So beckoning is the fireplace, the reminiscent of our ancestral life, that today there are television channels that broadcast a lit fireplace 24 hours every day!

Fire and Civilization
It was the mastering of fire that helped human beings pass from the Stone Age to the Metal Age. It is true that humans have already seen fire in the volcanoes, or a fire caused by the lightning in a thunderstorm, but they did not know how to invoke it, how to provoke it. The mastering of fire was important to create the first objects of clay and metal. Fire in the preparation of food gave man access to new sources of protein, an improved diet and better absorption of food.

For centuries, the fire remained trapped in the bonfire or in the forge of metals and in the potter’s oven. With the industrial revolution, an engine that functioned like a furnace was invented, which boiled water from which steam would exit to move the pistons that drove the wheels of a locomotive. From here to the propulsion engines, cars, ships, airplanes, rockets, was a short step.

We can read the history of human civilization as the history of fire and its use. Finally, we have the nuclear energy which transforms the heat released by the fission or the splitting of atoms and transmitted to water into mechanical energy to move the electric generator, producer of electricity.

The Genesis of Life
What is the origin of life on Earth? How did inorganic matter become organic matter? How did inanimate atoms and molecules transform into animate matter? Abiogenesis is the science that studies this transition. So far, there have been many theories proposed to explain how inorganic inert matter becomes organic living matter, but none without empirical evidence. That is to say, so far no one has managed to create life in a laboratory from inorganic matter.

The first living being or organism that appeared on our planet was a cell without nucleus, therefore prokaryotic, and without membrane. It appeared 4 billion years ago and is therefore almost as old as our planet which was formed 4.5 billion years ago. These bacteria were the archaea and cyanobacteria that began to carry out photosynthesis and paved the way for other life forms.

Later on, somehow, these cyanobacteria were associated, forming eukaryotic cells with nucleus, reducing the cyanobacteria to the chloroplast of these cells. Cyanobacteria still exist, they predate plants and animals, not being one nor the other; but is at the origin of two life forms: plant and animal.

Contrary to what seems logical, animals, not plants, were the first to leave the sea and populate the land. But if the animals were the first, what did they eat on land since there was nothing at the time? The animals were amphibians and they lived most of their life in the sea, but probably came on land to escape their predators or to lay eggs. However, it is known that the algae colonized the coastal rocks 1.2 billion years ago. Animals were the first to come ashore, but plants were the first to establish above water.

Even though cyanobacteria are also known as “blue-green algae”, they are strictly speaking not algae as the latter are restricted to eukaryotes, they are rather photosynthetic prokaryotes, the only prokaryotes able to produce oxygen.

Combustion and Respiration
Since combustion is the process by which combustible materials are oxidized with a release of energy and carbon dioxide, then, similarly, respiration consists of the oxidation of foods like glucose, amino acids and fatty acids, resulting in the production of energy and carbon dioxide. Until now there is no difference between the two, but in respiration not only is energy formed, other products are also formed, that is, more matter. This is why it is called metabolism, that is, a change or transformation.

Broadly speaking, this would be the only difference. However, if combustion instead of being complete is incomplete, that is, instead of being rapid it is a slow combustion, matter is also obtained, as in the case of respiration or metabolism. Think about how charcoal is made from wood: one places all the wood together in a pyre and cover the pyre with soil, leaving only one hole at the bottom and another at the top of the pyre. The wood burns in slow combustion because we limit the entry of oxygen and after a few days, we have all the wood turned into charcoal. If the oxygen was not limited, we would get ashes instead in no time.

The same is true of a long distance runner: if after the first minutes of running, on feeling tired from the increased heart rate, the athlete begins to breathe through his mouth and does not limit the oxygen intake, he will quickly tire and after spending all the glucose, he’ll have to stop. However, if he limits his intake of oxygen, he will force his body to change the fuel, so that instead of using glucose which burns rapidly and consumes a lot of oxygen, he will start to burn fatty acids which burn without the help of oxygen. In this way, he can run for a long time without altering his breathing or heart rate.

Another physical process of slow combustion is the degradation and rusting of metals, iron in particular. Over time, all objects containing iron, and there are many of them since iron is the most widely used metal, and even steel which is said to be stainless but under certain humid conditions, end up oxidizing, that is, burning or degrading due to the presence of oxygen.

Respiration or the Breakdown of Glucose
Glucose is the most widely used fuel inside living beings; the breakdown of glucose releases the energy that is contained in its chemical bonds. Glucose has 6 carbon, 12 hydrogen and 6 oxygen atoms, and in each bond between atoms there is an energy content. As glucose decomposes, energy is liberated and used by the body. Respiration completely breaks down glucose, turning it into energy and inorganic matter, such as carbon dioxide. There is yet another process that breaks down glucose, but only partially, since it transforms it into other organic products; this process is called fermentation.

Metabolism
According to the definition found in the dictionary, metabolism is the set of transformation that chemical substances undergo inside living organisms. It is these reactions that allow a cell or a system to turn food into energy, which will be used by the cells so they can multiply, grow and carry out their functions.

Metabolism is divided into two stages: catabolism (where there is degradation or breakdown of compounds) and anabolism (where there is the synthesis or formation of compounds). Let us recall that photosynthesis is also a two-stage process, and that the second stage cannot take place without the first. The process of making glucose and the process of its degradation, breakdown or decomposition, are similar.

Photosynthesis, which makes glucose from smaller molecules, is an anabolic constructive pathway; cellular respiration or metabolism, on the other hand, where glucose is broken down into smaller molecules, is a catabolic degradative pathway.

We have seen that in photosynthesis plants make their own food and part of it is used for their own consumption. The making of the food is photosynthesis; its use for self-consumption and growth is metabolism. Therefore, the plant cell is in some way more complex than the animal cell; it has a unique organelle that is lacking in animal cells: the chloroplast, through which it carries out photosynthesis. On the other hand, like the animal cells, it has the mitochondria by which it performs metabolism.

In metabolism, the anabolic phase of the cell uses glucose to construct cellular elements, to replace them when they are damaged or aged, and also for growth. In the catabolic phase, energy is released that maintains the constant temperature of the organism and the general functioning of all the tasks of the same organism.

Metabolism is a controlled combustion and it is not possible without the use of oxygen. In this combustion, the fuel is the proteins, fats and carbohydrates which, combined with oxygen in the air from respiration, produces energy which is used for the general functioning of the body, but is also partly stored for later use, and for the growth of the body. Everything in the universe obeys these same laws, functions in the same or in an analogous way.

In conclusion, if the plant life photosynthesis uses energy to make matter, the animal life metabolism burns that matter to make energy. Animal life metabolism as well as all man-made engines work under the same three principles.

Fr. Jorge Amaro, IMC

3 Reactants of Photosynthesis: Water - Sunlight - Carbon Dioxide

Einstein proved that matter and energy are one and the same, that is, that matter exists in the form of energy and energy in the form of matter. Intangible and invisible energy is susceptible of transforming into tangible and visible matter and vice versa.

If matter and energy did not have this facility to transform from one to the other, there would be no life on our planet. Life on our planet depends on two chemical processes: photosynthesis and combustion (metabolism). The two processes depend on each other, that is, for one to take place the other must also take place. Through photosynthesis, plant cells change sunlight into chemical energy; this chemical energy is then burned by the cell itself in the presence of oxygen.

Photosynthesis is a prebiotic function, that is, it is not yet in itself synonymous to life, because life is always associated with combustion (slow combustion or metabolism). Photosynthesis is the manufacturing of food in the form of glucose (sugar) by the cells; life is the combustion of this food using oxygen as the oxidant. Photosynthesis is carried out by plant cells which have the unique ability to fabricate their own food. This means that plants need not move about to search for food like animals.

However, the chemical reaction that keeps them alive is not photosynthesis, but rather combustion. They consume part of the glucose and oxygen they produce to stay alive, and have the energy to perform more photosynthesis. They release the rest of the oxygen into the air, and the stored glucose is used to feed the animals that eat them. Since photosynthesis can only occur during the day, that is, in the presence of sunlight, during the night the plants consume part of the glucose and oxygen they produce during the day. Even so, they still accumulate energy, that is, they grow and release the oxygen that other living beings need to live.

How did Life Appear on Our Planet
Plants generate all the food that exists on Earth; without them, Earth would be a dead planet. Four and a half billion years ago, Earth was formed from the collisions of thousands of meteorites in the emerging solar system. The planet was initially so hot that its surface was an ocean of lava.

Millions of years after the formation of the planet, Earth entered into a process of gradual cooling and this alteration gave rise to the formation of a thin layer of rock that covered the entire planet. With the cooling down of the Earth’s temperature, a large amount of gases and water vapour were expelled from the Earth’s interior. This process resulted in the gases forming the atmosphere, and the water vapour favoring the appearance of first precipitation.

However, as the temperature was still very high, when the rainwater touched the ground it evaporated instantly. It was only when the ground temperature cooled to below the boiling point of water that water accumulated, and oceans were formed. It was in the oceans that life first appeared.

The Origin of Oxygen
It may seem logical to think that just as water came before life appeared, so should oxygen the oxidizing agent of combustion come before the emergence of life. But this is not what happened. Life or a primitive form of life appeared first, and only then did oxygen appear. We could say that oxygen, although inorganic, has an organic origin. There may have been some oxygen in the Earth’s atmosphere 2.4 million years ago, but it was insufficient to create life. What caused the oxygen level to skyrocket and reach 21% in the atmosphere were the microorganisms called cyanobacteria or blue-green algae.

All oxygen in the atmosphere comes from water molecules. The latter is composed of two hydrogen atoms and one oxygen atom. In order for a water molecule to separate into its two simple elements, an electric current must pass through it. The breaking down process is called electrolysis, and it does not occur naturally. If the same result can be secured naturally, we would not need fossil fuel, and we would have an inexhaustible and eternally renewable source of energy.

Many people think that photosynthesis is the process by which plants turn carbon dioxide (CO2) into oxygen (O2), but this is not so. Oxygen does not come from a chemical reaction of carbon dioxide, but from water. It is produced during the first stage of photosynthesis when electrolysis occurs. The first microorganisms known to carry out photosynthesis on Earth are the cyanobacteria.

Cyanobacteria carry out electrolysis in the first stage of photosynthesis, as they are interested in the hydrogen that water contains, but not in the oxygen which they release. In other words, oxygen is a byproduct of this first stage. Cyanobacteria need the hydrogen because when combined with carbon dioxide, during the second stage of photosynthesis, glucose is synthesized. However, cyanobacteria could not extract hydrogen from water (which contains twice as much hydrogen as oxygen) without releasing oxygen as a “waste” product.

The very first microorganisms to emerge were the thermophiles, that is, they were able to survive in very hot environments, and to convert inorganic substances such as sulfur and carbon into energy. When the temperature of the atmosphere fell to 72 ° C, these microorganisms evolved into cyanobacteria, as this is the maximum temperature at which photosynthesis is feasible.

For billions of years, oxygen has been accumulating in the atmosphere, and the one that rose to the highest layers has become ozone. In this way the environment was formed and the conditions for life to diversify were created. All the plants on our planet feed in the same way as this microorganism, that is, through photosynthesis.

The Morphology of Cyanobacteria
Also known as the blue-green algae, already about 1500 species in 150 genera have been catalogued. Most species live in marine waters, lakes, rivers and even in very humid soils. They exist in a wide range of shapes and sizes: rods, spheres and filaments.

They measure only a few micrometers, that is, they can only be seen with the aid of microscopes. They reproduce asexually, are unicellular, but can be found in colonies or filaments. These microorganisms, in the aquatic ecosystem, form the so-called phytoplankton and are at the base of the food chain of this ecosystem. They carry out oxygenic photosynthesis (they use water as an electron source and release oxygen) and are autotrophic, since photosynthesis is their main way of obtaining energy.

Cyanobacteria appeared on Earth about 3 billion years ago. This dating is confirmed from fossils known as stromatolites, which were formed by these microorganisms. Because they have existed for so long, it is believed that they were responsible for producing the oxygen that accumulated in the primitive atmosphere.

The Chronology of Life on Earth
Our planet Earth was formed 4.5 billion years ago. After water settled in the oceans, the first thermophilic microorganisms appeared about one billion years later. Soon after, the cyanobacteria emerged, when the temperature of the seawater began to allow for photosynthesis. Cyanobacteria are simple microorganisms formed of cells without nucleus, that is, they are prokaryotes.

Two billion years ago, the eukaryotic cells appeared, that is, cells with nucleus that are the fundamental cells for life – all living beings, animals and plants, are made up of eukaryotic cells. Approximately 570 million years ago, there was the explosion of Cambrian life, marked by a burst of diversification of life on Earth, and the first non-plant organisms evolved.

About 438 million years ago, plants which until then only existed in the sea, began to populate the Earth. They were the first to leave the sea, which is logical, since all life on Earth depends on them. Years later, around 408 million years, the first amphibians emerged, the ancestors of the reptiles which came 50 million years later.

The extinction of the dinosaurs, the most emblematic reptiles on our planet, occurred 66 million years ago. After they were dethroned, Earth began to be dominated by mammals, and among them, the primates which came about 55 million years ago. Human beings are believed to have appeared 5 million years ago.

The Components of Photosynthesis
For a plant to able to photosynthesize, that is, to use sunlight to transform solar energy into chemical energy, and therefore be able to manufacture its own food, it needs three inorganic elements: water, sunlight, and carbon dioxide. To these elements we add the particularities of the plant cell, which has one component that animal cells do not have -- chloroplasts.

Water
The water in the vacuoles controls the intumescence or swelling of the plant cell. If the plant is left with little water, it withers; a plant with wilted leaves, that is, they have lost much of their intumescence due to a lack of water, decreases in volume and cannot perform photosynthesis well. Due to the thermal control capacity of water, it is possible for plants to absorb a large dose of solar radiation without temperature rising.

Water not only facilitates photosynthesis by keeping the cell vacuoles operational, but it is also an integral part of this chemical process. Plant chloroplast causes the photolysis of water, that is, it breaks down the water molecule into its simple elements: hydrogen and oxygen. It then releases the oxygen into the atmosphere as a byproduct, combining the remaining hydrogen with the carbon dioxide in the air for the subsequent reaction, which is the production of glucose, the energy and food for plant cells.

Sunlight
Light is a wave of electromagnetic radiation made of photons, with wavelength ranging between infrared and ultraviolet radiation. The light that seems white or transparent reveals part of its complexity when it passes through a prism or tiny droplets of moisture in the atmosphere, forming a rainbow. Of this electromagnetic radiation, only one part is visible to the human eye, and this visible light spectrum ranges from 380 to 760 nanometers, from violet to red.

Sunlight is the only source of energy on our planet. All types of energy that we have on Earth, in the final analysis, come exclusively from the sun. Without oxygen there would be no life, without photosynthesis there would be no oxygen, and without the sun there would be no photosynthesis.

It is the sun that sets into motion the cycles upon which life rests: the oxygen cycle, the water cycle, the nitrogen cycle, and many, many other cycles. Without solar energy this would be a dead and dark planet. It is the solar energy that makes it possible for organic elements to combine and produce organic life.

Carbon Dioxide
This gas is nowadays widely talked about as being responsible for the greenhouse effect, which causes the rising of the atmospheric temperature. It is therefore viewed in a negative light as it does not let heat escape from Earth into the space. But plants need carbon dioxide, and life in general also needs it. All organic molecules are a combination of carbon and hydrogen atoms; a molecule which contains both carbon and hydrogen can never be inorganic.

In photosynthesis, this is precisely what happens: the combination of hydrogen, that the plant obtained from the decomposition of water molecule, with carbon dioxide that it gets from the atmosphere produces glucose, that is, a food for life. In fact, the more CO2 humans emit into the atmosphere, the more plants absorb it and the faster they grow.

The ability of plants to remove CO2 from the atmosphere has doubled, it is as if they want to find the solution to our problem of excessive greenhouse effect. That is why despite tropical deforestation, the planet’s vegetative mantle is increasing. But even so, all the terrestrial and marine forests are not enough to purify the atmosphere and prevent its temperature from rising.

Chlorophyll
Chlorophyll is the light absorbing pigment on the thylakoid membrane inside of the chloroplasts. Plant cells are autotrophic, that is, they make their own food. Animal cells are heterotrophic because they feed on life, that is, on other living organisms and do not make their own food. In some ways, we can say that every kind of life depends on plant life, that is, animal life is a parasite of plant life.

It goes without saying that animal life, especially human life, is much more complex than plant life. However paradoxically, at cellular level, the plant cell has practically everything that the animal cell has, and one more organelle that the animal cell does not have: chloroplasts. Whereas animal cells only carry out metabolism, that is, transform matter (food) into energy, plant cells not only carry out metabolism, but also photosynthesis, the opposite of metabolism, where energy is transformed into matter (food).

It is worth remembering that plant cells also have mitochondria where their metabolism takes place, and like in animal cells, is essentially a slow combustion. The difference is that plant cells metabolize or burn the food they themselves have made, carried out with the help of oxygen, the oxidizing agent which they have also made, and still have leftover of both for other living beings that depend on them to survive.

Chlorophyll carries out the main function of photosynthesis: the extraction of energy contained in sunlight to produce carbohydrates. An interesting aspect is that when we look at the atomic structure of chlorophyll, we see a great similarity with the atomic structure of hemoglobin. The chlorophyll molecule consists of a central magnesium atom, which gives it the green colour, surrounded by a nitrogen-containing ring to which a long carbon-hydrogen side chain is attached. The hemoglobin molecule has the same nitrogen-containing ring but with a central iron atom instead, which gives it the red colour. The chlorophyll molecule has a much longer carbon-hydrogen side chain than the hemoglobin molecule.

There are several types of chlorophyll molecules, each one is tuned to or absorbs different wavelengths of light within the visible light spectrum.

• Chlorophyll a: is the pigment that gives the blue/green colour in plants and absorbs violet and orange light the most, at 430 nm and 660 nm, respectively. It doesn’t absorb green, so the green light is reflected to our eyes
• Chlorophyll b: is the yellow/green pigment present in plants and absorbs mostly blue and yellow light, at 450 nm and 640 nm, respectively. It also does not absorb green.
• Carotenoids: these are yellow, orange, and red plant pigments, present in all photosynthetic organisms; and absorb light maximally between 400 to 550 nm.
• Phycobilins: these are red and blue pigments, found in red algae and cyanobacteria, respectively. They absorb light of wavelengths between 500 and 600 nm. 

The Process of Photosynthesis
It is the most important biochemical process for life on our planet. The second would be metabolism, but without photosynthesis there would be no metabolism, since it is from photosynthesis that the fuel and the oxidizing agent of combustion that we call metabolism are produced. Photosynthesis generates the base of the food chain of the entire planet.

Every day we feed on the sun, whether we are vegans, vegetarians, carnivores, omnivores or pescetarians. Ultimately, what we are essentially eating every day is sunshine!

The Photochemical Stage (Light Dependent)
In the first stage, water plus sunlight releases oxygen by electrolysis or photolysis. The free electrons from the water molecule use the hydrogen released in the photolysis as a carrier to enter the chloroplast organelle, on the thylakoid membrane inside the chloroplast. Here light energy is converted into chemical energy (ATP) and reducing power or electron donor (NADPH). These two substances trigger the next stage or the biochemical stage of photosynthesis. Therefore, ATP and NADPH are the end products of this first stage, in which sunlight is needed.

The Biochemical Stage (Light Independent)
This stage is much more complex than the first, it is also known as the Calvin Cycle. It consists in short of three steps: fixation, reduction, and regeneration. It starts with the most important enzyme in the world, code name RuBisCo. This substance captures carbon dioxide in the atmosphere, mixes it with a molecule called ribulose bisphosphate (RuBP); in short, fixing the carbon from its inorganic form in CO2 into organic molecules (3-PGA). The next step is a reduction reaction in which electrons are gained by the 3-PGA molecules, supplied by NADPH and ATP, to produce G3P molecules. In the last step, some G3P molecules go to make glucose/sugar, and the rest is sent to regenerate RuBP molecules needed for the fixation step and the cycle repeats. The overall chemical formula for the photosynthesis process is as follows:

6CO2 + 6H2O + sunlight = C6H12O6 (sugar) + 6O2

Conclusion
Today the planet is covered with vast forests and wooded areas; yet 70% of the oxygen in the Earth’s atmosphere does not come from land plants, but from the marine plants in the ocean. It was there that photosynthesis began and it’s still there the photosynthesis that provides us with most of the oxygen that we breathe. We could say then that the photosynthesis of land plants feeds our bodies, and that of the sea allows us to breathe.

The complex chemical reaction that uses sunlight to release from water the oxygen that we breathe and combines the remaining hydrogen with the carbon dioxide in the air to produce the food we eat, is indeed the Big Bang of life on Earth.

Fr. Jorge Amaro, IMC

3 Components of the Cell: Membrane - Cytoplasm - Nucleus

Just as the atom is the building block of matter, and all inorganic matter is a sum and mixture of atoms, the cell is the building block of life, and all living organisms are composed of cells that arose from pre-existing cells. Without atoms there is no matter, without cells there is no life. As the atom is trinitarian so also is the cell which is divided into membrane, cytoplasm and nucleus.

Information – Energy – Time/Space
All life forms consist of these three elements: information and energy that occupy a space for a period of time. All living systems process information, and without this the living organism ceases to be alive. This information is contained in a molecule called deoxyribonucleic acid or DNA. It is the genetic code of life, that is, the essential information or the database to build and maintain a particular life form.

DNA is composed of two long strands of base pairs along with sugar and phosphate molecules, all spiraling to form a double helix. Like a twisted ladder, the base pairs form the rungs, and the sugar and phosphate molecules form the two vertical sides of the ladder. The information for building all the proteins that our body is made of is encoded in the DNA molecules. In other words, it is the DNA that instructs the cells to make the proteins essential for our growth, development and health.

From the colour of our skin to the colour of our eyes and hair, how tall we are going to be and even the diseases we may develop in time, all the information about our body is contained in the DNA; because we carry such precious information, it is so to say kept under lock and key inside the nucleus of each of our cells.

Protein formation is a very intricate process. When a particular protein is needed, in order to keep the DNA safe and unaltered, the instruction on the DNA molecule to make that protein is copied inside the nucleus onto another molecule called ribonucleic acid, or RNA which is similar to DNA, but instead of two strands it is single stranded, and can be found both in the nucleus and the cytoplasm of each cell.

For all this to work, a power source is required. This source of energy is ultimately the sun, because all forms of energy come from the sun. By the process of photosynthesis, cells with chloroplasts transform solar energy into chemical energy that will feed the cells or provide the raw materials like oxygen for all vital processes in other cells.

We can now biologically define life as being what distinguishes the animal or plant kingdom from minerals and metals, the organic world from the inorganic, or the animate world from the inert one. A living being is an organism that is self-contained and maintains a certain independence from the environment in which it lives and thrives. It keeps an internal equilibrium or homeostasis, and is composed of one or more cells that maintain life via metabolism or biochemical processes. It has the capacity to grow and adapt to its environment, to respond to stimuli, to reproduce and to die.

I believe that life appeared spontaneously on Earth when the right conditions were created for it to emerge. God kicked off with the Big Bang and the rest came about spontaneously, in a continuous succession of cause-effect-cause… and so on until we reached human life.

But all this occurred according to God’s design, who knew beforehand the final result of the sequence of causes and effects; that is to say, He knew that it would lead to the emergence of a being, the human being, in His image and likeness. In fact, like God, human beings also have the capacity to create. The only difference is that God creates out of nothing, while humans mix elements already created to transform them into new things.

We all know that living or organic matter is composed of inorganic elements. However, the passage from the inorganic to the organic is still today the great mystery in biology. Many scientists have sought to recreate the earthly conditions when life first began, placing in this environment the fundamental elements of life, and yet have not managed to create life. Life is God’s creation, it is His property, it belongs to Him, and like the secret of Coca-Cola it is not revealed. Living beings (and we are the living beings created by God) do not create life, they only transmit it.

From the Atom to the Cell
The combination of two or more atoms of different chemical elements forms a compound. The smallest unit that retains the properties of a compound is the molecule, which can be as simple as the water molecule (H2O) or as large and complex (macromolecule) as a molecule of protein or nucleic acid.

The chains of carbon atoms bonded to hydrogen, oxygen, nitrogen, and small amounts of sulfur (S) and phosphorus (P) form the majority of organic compounds found in living matter. Most of these compounds are classified under four groups: proteins, carbohydrates, lipids and nucleic acids, which constitute the raw materials for the formation of the supra molecular structures that make up cells, such as membranes and organelles.

This organic matter still needs inorganic matter in order to obtain life, therefore, in addition to the organic substances, we find in the human body inorganic substances such as water (H2O) and mineral salts. Animal cells are formed chemically by organic compounds and inorganic substances, in different proportions:

Proteins: 17.8 %
Carbohydrates: 6.2 %
Lipids: 11.7 %
Water: 60.0 %
Mineral Salts: 4.3 %

Proteins
Proteins are macromolecules made up of many smaller molecules, or amino acids, composed of carbon, hydrogen, oxygen and nitrogen atoms; some also contain small amounts of sulfur. There are twenty different amino acids that participate in protein structures, eleven of them are synthesized by human cells and the remaining nine must be obtained from protein-rich foods such as soy, legumes and meat.

Carbohydrates
Carbohydrates are molecules made up of carbon, oxygen and hydrogen atoms. The principal characteristic of carbohydrates is its role in energy for action, that is, whenever energy is required by the body to do work, one needs to resort to a diet rich in this compound. These foods are mostly of plant origin such as cereals, legumes, fruits, roots, and starchy foods like potatoes and rice.

Lipids
Fats, also known as lipids, are organic biomolecules composed mainly of hydrogen, oxygen and carbon atoms. Other elements, such as phosphorus, are also part of the lipid composition. Like carbohydrates, they supply energy to the cells, participate in the composition of the cell membranes, and act as thermal insulator in some animals. There are two types of lipids: saturated, of animal origin, and unsaturated, of plant origin.

Nucleic Acids
There are two types of nucleic acids: RNA (ribonucleic acid) and DNA (deoxyribonucleic acid), both are formed from smaller units called nucleotides. Each nucleotide is chemically made up of a phosphate group that confers acidity to the unit, a 5-carbon sugar, and a nitrogenous base (adenine, cytosine, guanine or thymine/uracil). The storage and transmission of the genetic information is the responsibility of the nucleic acids, therefore, they are the most important biomolecules in cellular control because they contain the genetic code.

Recapitulating the path that life takes starting from the atom, the smallest form of matter, this is its course: subatomic particle – atom – molecule – macromolecule – organelle – cell – tissue – organ – organ system – organism or body…

The Cell and Its Internal Structure
Like the atom is the building block of inorganic matter, the cell is the building block of organic or living matter. The cell is in itself a living being, the smallest one in nature; the amoeba, for example, is a single-celled organism. One main difference between the amoeba and other living organisms is in the number of cells. An adult human body contains trillions of cells, although they all began from a single cell, just as all multicellular organisms begin from a single cell at the moment of conception.

All cells can be classified structurally as either prokaryotes or eukaryotes. The prokaryotes are predominantly single-celled organisms of the domains Bacteria and Archaea, and they do not have a nucleus or any other membrane bound organelles. The cells that we are interested in are the eukaryotes, that is, cells with nucleus that are common to all plants and animals including humans.

External Membrane
The cell membrane is the outer boundary of a cell that separates it from the world outside, it is the protective barrier of the cell. It defines the cell as the smallest unit of life – hence the word “cell” from Latin cella, meaning “small room”. It imparts shape and size to the cell, and keep other components within. All cells have a cell membrane. The membrane permits the passage of certain substances and impedes the passage of others, that is, it controls what comes in and what goes out of the cell. In animal cells oxygen and nutrients can enter while carbon dioxide and other waste products can go out.

Cytoplasm
Inside the cell membrane, the cell is filled with a gelatinous substance called the cytoplasm. All the organelles float inside this medium.

What Are Organelles
Organelles are the tiny organs of a cell. A cell is fundamentally a free and independent living being, and like the body of an animal, it contains organs for specific functions: respiration, digestion, elimination of toxins etc. In this way, a cell has its own tiny organs to perform vital functions. Let’s look at the different types of organelles in an eukaryotic cell.

Endoplasmic Reticulum is the transport highway of the materials within the cell; it connects different parts of the cell and helps in the exchange of materials. It can be rough, if its surface is studded with ribosomes, or smooth if it is ribosome-free. The former is involved in the production of protein products and the latter is involved in lipid synthesis and detoxification of drugs and poisons.

Mitochondria is the power plant of the cell where cellular respiration occurs. Although cellular respiration is a combustion reaction, it does not resemble one when it occurs in a living cell because energy is not created from one rapid reaction, but is released slowly from a series of reactions. Nutrients are oxidized in the presence of oxygen, resulting in energy and carbon dioxide. In other words, mitochondria convert the energy from food into a form that can be used by the cells to keep and sustain their lives.

Unlike other organelles, mitochondria are semiautonomous, that is, they have their own DNA which is inherited from the mother only, and can replicate independently of the nucleus. Because of this, researchers believe that mitochondria have evolved from a primitive eukaryote that ingested a prokaryote, with the two developing a symbiotic relationship.

Lysosomes are the sacs containing enzymes that aid in the breaking down of food ingested by the cell. They are also important in removing old cellular components and replacing with newer ones. Sometimes they are called to destroy the cell itself, and are therefore called the suicide cell sacs.

Golgi Apparatus is where proteins are mixed with other chemicals and repackaged, and then released from the cell surface.

Ribosomes float freely inside the cytoplasm or are bound to the surface of the endoplasmic reticulum; their job is to produce proteins. The bounded ribosomes produce proteins that are released from the cell to be used elsewhere, and the free ribosomes produce proteins that are used inside of the cell itself.

Chloroplasts are solar power centers in cells of plants and algae where photosynthesis takes place, that is, the generation of energy using water, carbon dioxide, and sunlight. They are the counterparts of mitochondria in animal cells, where cellular respiration or combustion takes place. Like mitochondria, they also contain their own DNA and are also believed to have evolved via symbiosis.

Vacuoles are the wrappings used to store and move substances that are ingested, excreted, processed or digested by the cell. Vacuoles are found in both animal and plant cells, but are much larger in the latter.

Nucleus
It is the brain of the cell that controls all its vital functions, and allows the cell to function like an independent living being. The nucleus is separated from the cytoplasm by a porous membrane that allows certain molecules to enter and exit the nucleus. The chromosomes are contained within the nucleus which carry the genetic code responsible for hereditary traits.

In the DNA of most cell in the human body, we can find the complete blueprint for all the proteins that are necessary for somatic life. The genetic information encoded in the DNA is transcribed into the messenger RNA which carries the code to the ribosomes in the cytoplasm, and these in turn take the information and translate it into proteins.

As a living organism, a cell can be compared to the social life within a medieval castle made of external walls, inner walls and the keep or tower where the royal family lives. The external walls represent the membrane, that protects the cell from the outside and controls what comes in and what goes out; the inner walls, between the keep and the external walls where people live and interact, represent the cytoplasm where all chemical reactions inherent to life occur; the keep or tower where the royal family lives represents the nucleus of the cell where the DNA that commands all cell operations reside.

Cancer, Disease of the Cell
The cell is the simplest element of any organism. The average human body is made up of an estimated 30 to 40 trillion cells. Since each cell is a living organism, our body is formed by trillions of living organisms that stick together because they all originated from a primordial cell that was formed by the union and fusion of a half cell from each of our parents.

As we have said above, cells, like all living organisms whether plants, animals or humans, are born, grow, reproduce, and die. Each cell, before dying, transmits its genetic material to its descendants, so that it can continue to fulfill the same function as its “parent”. In a simple way, cancer occurs when cells refuse to die and instead, keep multiplying in a disorderly manner.

In reality, cancer is nothing but a civil war within one’s own body: some cells resolve to multiply in a disorderly and uncontrolled fashion. These cells are in a way suicidal, because by completely dominating the body, precipitating its death, they end up dying themselves. Deep down they are suicide bombers, they kill by dying or they die by killing.

Human cells are continuously regenerating. The human body produces roughly a million billion cells in a lifetime. Each time a cell divides to give rise to another, its DNA is copied. The daughter cells resulting from cell divisions must be the exact copy of the parent cell. In other words, the genes of the daughter cells must be identical to that of the parent cell.

In practice, however, small alterations in the DNA molecules that we call mutations can arise, which may be caused by several factors or may simply be random errors. Cancer cells are cells with gene mutation and therefore they don’t have the proper instructions to carry out the duties of their counterparts. Instead they divide out of control, are immature and do not do the job they are created for, they don’t stick to their own kind, and can spread to other parts of the body to attack other tissues and organs.

Even if we were to rid ourselves of all internal, emotional and physical carcinogenic factors, as well as external ones, we would not be completely free from the scourge of cancer, because the error may be a random event during cell division. Fortunately, most errors result in cell death. However even Egyptian mummies have been found with cancer, which leads us to conclude that this is as old as humanity.

It is therefore a real game of Russian roulette whether we get cancer or not during the course of our lifetime, with the likelihood increasing the longer we live. The only hope is that science will develop more sophisticated methods of detecting gene mutation shortly after it occurs, and thus be able to correct it before the mutated cells have the chance to divide out of control.

Fr. Jorge Amaro, IMC

3 Rules of sustainable development: Environmental - Economic - Sociopolitical

Our planet’s biosphere, our common home, is not as vast as it seems. The portion of the biosphere that is intimately linked to man’s survival is in fact quite small. In the oceans, it is only a kilometer deep, in the land only two meters in depth, and the ceiling is relatively low, since beyond 7,000 meters the air is unbreathable and the cold is unbearable.

With such a low ceiling and thin layer of breathable air, it becomes difficult to understand how there are still people who do not believe that human activities such as the burning of fossil fuels and other industrial activities have a harmful effect on our habitat.

The History of the Concept
With the industrial revolution, the mechanization of agriculture, the expansion of trade and globalization, the Western world, the developing countries and the poor countries, in this order, have experienced an unprecedented development at all levels: increased production, population increase, increased consumption, increased needs for energy, and increased means of transportation, especially planes and automobiles, to the point that each family in the richer countries owns more than one car. Sadly, pollution and the environmental deterioration have been the inevitable consequences of this unbalanced development.

Only our planet did not increase, and since it did not increase, the results of this too fast and haphazard growth soon appeared, especially because of the “use and throw away” philosophy that has been in force for several decades. The concept of recycling is recent, and has not yet entered the minds of many people, which is quite strange as we have said in the previous article about the cycles of water, nitrogen, carbon, oxygen etc. which showed that life on this planet has always depended on recycling finite amounts of elements.

Recycling has always been the philosophy of life on our planet, although its inhabitants have lived for a long time, and many will still do, according to the “use and throw away” thinking. Nowadays, it is cheaper, and less hassle, to buy new than to repair. But to which is it cheaper? To the economy or to the planet? What kind of toll do we place on our planet with this type of short-sighted ill-considered choice?

The idea of sustainable development emerged at the United Nations Conference on Environment and Development in Rio de Janeiro, in 1992. Initially, only the environmental impact on development was considered, that is, the capacity of our planet to sustain a given level of development without depleting its resources or jeopardizing the lives of the future generations. The other two pillars – economic and social – appeared later.

It is easy to know whether what we are doing is sustainable or not; we just need ask ourselves if we can continue doing this over and over again, forever? The first thing to inquire is the environment – does it compromise the environment for the next generation? Secondly, we need to ask if it is conducive to economic growth. And thirdly, if this economic benefit extends to all or only to selected few, and whether it promotes peace, justice and social stability.

What we have seen so far is that the wealth that some produce is proportional to the poverty they cause, in short, the more wealth, the more poverty. Furthermore, in relation to the environment, we have lived with the mentality of the mule that says “after I die if there is no more grass that grows on all the Earth, I don’t care for I no longer need it”.

Development seen solely as economic growth destroys the environment and causes deep social inequalities. For development to be sustainable, it has to be tridimensional, that is, the aspects of social justice and environmental protection should be just as important as economic growth.

The Real Situation
“Long before we exhaust the physical limits of our planet there will be grave social upheavals provoked by the great divide existing between the income of rich countries and poor countries.” III Report of the Club of Rome (1976)

For a bench to stand, it must have at least three legs; it cannot stand on one or two; this is the same with sustainable development. Capitalism has long inflated economic development without thinking of the other two and this has created a world where 1% of humanity has more wealth than the remaining 99%.

More concretely, one percent of the world population holds 54% of the world wealth and the rest of humanity only 46%. The difference is abysmal and even worse is that the gap between the rich and the poor continues to grow… The capitalism that has created the middle class is destroying it, even in the rich and developing countries.

Immigration – The “grave social upheavals provoked by the great divide between the income between rich countries and poor countries” advocated by the Club of Rome are already happening. To defend themselves, the rich have entrenched themselves behind thick walls, some in process of being constructed between US and Mexico, others in the form of natural barriers such as the Mediterranean Sea, preventing the Africans from entering Europe.

The poor are barred from entering the European fortress or into North America, or Japan or Australia. However, the highly qualified professionals, surgeons, football players, musicians, architects, and lawyers always have the doors open to them. To the poor countries we search for raw material at low cost, cheap labour, human trafficking for adoption (not all bad), but also for prostitution, organ trafficking etc. This leads us to the next issue – globalization.

Globalization – Through globalization, the Earth functions as a unit. The means of communication have removed the constraints of space and time. Today, we no longer get to know what happened in the recent past, we get to know while it is still happening.

But beyond the informational aspect, globalization is fundamentally economics and its leaders are less and less the states and more and more the multinational companies. In the continuing quest for cheap manual labour, which often involves child labour, the multinational brands and logos call for a lifestyle and form a global culture that little by little replaces the local culture.

Globalization per se would not be bad in fostering close communication among all peoples. Following the physical principle of the communicating vessels, when we connect an almost empty bucket of water to a full one, water flows from the bucket that has more to the one that has less, until equilibrium is reached between the two. In principle, through globalization we should reach equality between peoples.

The problem is that globalization is an invention of the rich to exploit the poor. The communication is made through valves which are devices that allow the movement to happen in only one direction. In this case, the movement occurs from the poor countries to the rich and not from the rich to the poor.

Atmospheric Contamination – The industrial civilization derived its energy mainly from non-renewable raw materials (fossil fuels, especially coal and oil). It used these raw materials without control, as if they were inexhaustible. Air pollution is increasing at an astonishing rate: it has doubled in a single decade. The Earth’s ability to sustain this contamination and avoid its harmful consequences is limited.

Industries and automobiles remove large amounts of oxygen from the air, and in return emit large quantities of carbon dioxide. As the result, we are breathing more and more rarified air that can cause diseases, namely cancer; it also raises the average temperature of the planet by increasing the greenhouse effect, thus trapping too much heat, not letting it escape into space. Our planet is heading towards a planet like Venus by the ever increasing amount of carbon dioxide.

From the point of view of biology, the human species is doomed to extinction if it persists in destroying its environment. Every organism that destroys the environment in which it lives, will end up destroying itself. Science affirms that in order to survive, it is not enough to cut the CO2 emissions by 20% or 60% by 2050, it is necessary to cut it by 90% by 2030.

The Problem of Water – In many countries, the lack of water is the main reason why people cannot get out of poverty. Around 3.4 million people, mostly children, die every year from diseases associated with the shortage of safe drinking water, inadequate sanitation and lack of hygiene. The waterborne diseases are the leading cause of death worldwide – 80% of all diseases in the world. It is predicted that by 2035 half of the world’s population is expected to live in conditions of “insecurity” in relation to the supply of drinkable water.

• “If the wars of this century were fought over oil, the wars of the next century will be fought over water.” Ismail Serageldin, World Bank vice president in 1995
•  “The next war in the Middle East will break out due to scarcity of water supply.” Muammar Gaddafi
• “The conditions are set for a century of conflicts over water.” The Economist

 The Plastic – We are not just talking about the tons of plastics found in the stomachs of whales, but the micro plastics coming from the microfibers that are part of our clothing are even worse. These come from the washing machines, go into the rivers and seas, and become part of fish diet which we later consume.

In addition to plastics, fish are no longer a healthy choice of food that they once were because of the levels of mercury present in the sea water continue to rise. The older the fish, the more mercury is absorbed into its system.

A Planet With Only Duties – No one defends the rights of the planet. The Earth has no rights, it only has the duty to feed us. If we don’t take good care of it, it cannot take care of us and sustain our life.

Deforestation – Livestock farming or monoculture, of soya beans for example, is causing desertification. The land used was rich only within the forest ecosystem; without trees, it is quickly depleted, and it becomes necessary to resort to chemical fertilizers so that some agriculture can be practiced.

Deforestation is proceeding at a rapid pace, without taking into account that growth or recovery is slow. We need the trees, not so much to produce oxygen, because the great majority of oxygen comes from the marine forests, but to absorb CO2.

Forest fires of criminal origin that occur systematically in Portugal, California, Australia, have killed hundreds of people year after year, in addition to emitting CO2 into the atmosphere and desertifying previously luscious leafy zones.

The ozone layer, or the blue gas that protects us from solar radiation, has decreased so much due to the use and misuse of aerosols that it is no longer good for health to sunbathe. The truth is that we need very much to be exposed to sunlight in order to synthesize vitamin D which is so important to our overall health.

Garbage – Our cities produce tons and tons of garbage every day. On one hand, there is an increasing public awareness to recycle household waste in large cities, and on the other, it is forbidden to recycle leftover food by feeding it to animals. As the result, a lot of food ends up in the trash, which is in itself contradictory to the new mentality of recycling.

Oil tanker accidents at sea ruin the ecosystems for many years. It takes a long time to clean them up. Crimes, like the deliberate blaze of oil wells during the Iraq war that lasted years, have ejected into the atmosphere billions of tons of CO2.

Not many years have passed since the beginning of space exploration and already the orbit of our planet is littered with orbital debris or space junk comprised of various old satellites that stopped functioning. Everyone is thinking of putting more and more satellites into orbit, but no one thinks of retrieving those that no longer work.

The Attitude of Denial – We are sweeping the problems under the carpet. We postpone finding answers to the problems we have at this moment which will only get worse in the future. The attitude in general is that of denial, of not wanting to see, of not taking responsibility for the present behaviours that will deny the future of the next generations. God forgives always, human beings only sometimes, but Mother Nature does not forgive nor forget. Someone once said that with respect to the poisoning of our planet it is like poisoning the placenta that feeds the child.

Greenpeace has stated that if all the inhabitants of the planet were to live like the citizens of the rich countries, consuming and wasting the resources of our planet, the Earth would sustain life for a meager 3 months and then would die, contaminated and depleted of resources. For the latter not to happen, it would take the resources of 10 planets like ours.

Sustainable development is based on the principle that a sustainable and viable economic development is possible without destroying the environment or compromising justice, the world peace, and the habitability of the planet for the future generations.  Sustainable development is one that harmonizes economic growth with the reality of the biosphere or the protection of the environment and the individual and social needs of all the peoples living on the planet, that is, with the social inclusion of all.

Protection of the Environment
Regarding air quality, which is the most burning ecological problem, carbon dioxide that the economy emits into the atmosphere should not exceed the amount that plants can absorb by photosynthesis. It is similar to the scenario that a person should not drink more alcohol than his liver can break down. Currently, we are not able to maintain this balance.

Environmental degradation causes problems of physical health, but on the other hand, this same degradation arises from the moral and social values of people who annihilate the preservation of the environment. Forty-six percent of the world population lives in cities. This is why it is necessary to improve the air quality in urban centers by building more green spaces in the middle of cities that can improve the air and trap dust particles.  The covering of roofs of homes with solar hot water and photovoltaic panels connected to the electrical grid would save a lot of energy when it is most needed: during the day.

The environmental impact analysis refers to the care to be taken when building a business. The impact it will have on the ecosystem, on plant and animal life, needs to be calculated and considered without compromise. There are more and more species of plants and animals that are disappearing from the face of the Earth, and what is scary is a future where plant and animal life will be reduced only to those produced by agriculture and domestic animals – the planet will have no wild animals because there will be no more forests as these will be occupied by man.

At the time of this of writing, it is becoming big news the dramatic decrease of insect population due to the abuse of chemicals in agriculture. The insects are the ones responsible for the pollination of agricultural plants; without them there is no agriculture.

Economic Growth
A company needs to be profitable for it to survive and continue to exist. The problem is to make profit at any cost. There are many so-called “healthy” economies that operate at the expense of the health of the human beings who sustain them. What will be more important: the health of the economy or the health of those who sustain the economy? Paraphrasing the Gospel, the economy was made for man and not man for the economy. A healthy economy based on the exploitation of those who maintain it through low wages, no holidays, with shifts of more than 8 hours, will sooner or later collapse, since companies cannot operate in this way for long.

In order for an economy to be healthy, it has to have a balance between births and deaths; it has to have enough young workers to replace those who achieve reform and subsidize their reforms – or that what is called solidarity between generations.

In the last 200 years, the world economy grew six times more than in the past, and in the rich countries ten times more. This economic growth occurred at the expense of coal, in the first phase of the industrial revolution, and of oil in the second. To save the Earth we should move immediately toward renewable energies. But if we move in this direction, the economy will cease to grow as it has done in the recent past. On the other hand, the rich countries’ mode of life is not sustainable because if all peoples were to live according to this model, the Earth would die shortly.

To care for the Earth and at the same time let the poor live with more dignity, there can be no economic growth in the rich countries. We would have to lower our standard of living, but since we are not doing this, we find mechanisms to ensure that the rich are always rich and the poor always poor. For this reason the sustainable development is a utopia, a chimera.

Social Inclusion
Sustainability should be sought locally by each company. It should look around itself and bring together all those whose lives are touched by the company: suppliers of raw material, producers, transporters and consumers of the products. All must be included, because they form a greater community. If one loses, all lose in the short or long term.

A company that cares about its workers, that shares its profits among them, and supports social causes, is a company esteemed by workers who are motivated, productive and work better – whoever runs for love does not tire. The explorer explores the Earth, if a company exploits both the environment and the workers, thinking solely of profit, it will end up losing both.

Politics play an important role in rewarding companies that are sustainable at all three levels and penalizing those that are not, because they pollute more, because they do not take care of their employees, etc. In this way, being sustainable becomes now fashionable, because there are financial incentives in place. This is one way that politics tries to influence the economy, so that the latter is not the only one driving the world. All business activity must be economically profitable, socially just, and environmentally sound.

At the company level, this seems to be relatively easy and doable. During the first industrial revolution, there were some businessmen who, in a personal capacity, applied these models and were called philanthropists. To extend these practices to the global level does not seem to be as easy. However, according to the slogan “Think globally and act locally”, sustainability must be sought by each and every company but not imposed in an ideological manner.

Seventeen Sustainable Development Objectives for 2030
These were the millennium goals. As they were not realized within that time frame, they became the goals for 2015; and as the deadline passed once again without achieving them, they are now the objectives for 2030. We will see if they will finally be reached that year, but it does not seem that we are heading in that direction, when several countries have already abandoned the agreements signed such as the one in Paris and others, without fulfilling them.

1. End poverty in all its forms, in all places;
2. End hunger, achieve food security, improve nutrition and promote sustainable agriculture;
3. Ensure a healthy life and promote the well-being for all, at all ages;
4. Guarantee inclusive and equitable quality education, and promote lifelong learning opportunities for all;
5. Achieve gender equality and empower all women and girls;
6. Guarantee availability and sustainable management of water and sanitation for all;
7. Guarantee access to cheap, reliable, sustainable and modern energy for all;
8. Promote sustained, inclusive and sustainable economic growth, full-time and productive employment and decent work for all;
9. Build resilient infrastructures, promote inclusive and sustainable industrialization, and foster innovation;
10. Reduce inequality between and within countries;
11. Make cities and human settlements inclusive, safe, resilient and sustainable;
12. Ensure sustainable consumption and production patterns;
13. Take urgent action to combat climate change and its impacts, recognizing that the UN Framework Convention on Climate Change (UNFCCC) is the principal international and intergovernmental forum to negotiate the global response to climate change;
14. Conserve and promote the sustainable use of oceans, seas and marine resources for sustainable development;
15. Protect, restore and promote the sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and loss of biodiversity;
16. Promote peaceful and inclusive societies for sustainable development, proportionate access to justice for all and build effective, accountable and inclusive institutions at all levels;
17. Strengthen the implementation mechanisms and revitalize the global partnership for sustainable development.

Be Part of the Solution and Not Part of the Problem
“Water and air, the two essential fluids on which life depends, have become global trash cans.” Jacques Cousteau

The market produces everything we want, according to the law of supply and demand. This law places an enormous power in our hands: through our demand, we have the capacity to influence the supply of the market. As consumers we are not aware of this power, but the producers of goods acknowledge us, for this reason they say that the client is always right.

The economic system of our society has accustomed us to use and enjoy consumer goods without educating us of their acquisition – it does not tell us how these good are made, by whom, under what working conditions, with what resources, how far they travelled to reach us.

As consumers, by our choices, we send messages to the market – if we prefer a product with certain characteristics, the market will try to produce it; if we choose to buy products from companies that adopt conducts that respect their employees and the environment, the market will ipso facto orient itself in that direction.

Similarly, if we reject a product because it was produce against our values, travelled many kilometers to reach us, used cheap labour or, even worse, child labour, contaminated the environment, if we set it aside and stop buying it, the market will in turn cease to produce it; it is enough that the sales fall by a mere 5% for the market to reorient itself.

In addition to being aware in our daily lives and adopting good ecological habits in our personal lives – such as saving water in the shower, walking short distances instead of taking the car, recycling household waste, turning off excessive and unnecessary lights – the use of power that we have as consumers has immediate and lasting effects that contribute to sustainable development based on the protection of the environment and on economic growth where everyone wins.

Fr. Jorge Amaro, IMC