Cultura Brasileira: no ar desde 1998

Where do we come from - Continuation - Evolution and Natural Selection


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 Charles Spencer Darwin (1809 - 1882)



As for the philosophers of classical Greece - between 1,000 and 500 years before our era - as perceived and described, the similarities between the animal species, for example, all have - in slightly different distributions in each species: Anatomical Organization (two upper limbs, two legs, a torso, a head, similar internal organs...), Sexual Reproduction, Locomotion and such, mainly arise naturally in species as diverse as rodents, dogs, cattle and primates, like us.

At the first part of these considerations we have seen how the advance of religious fundamentalism silenced the pursuit of knowledge through observation and experimentation rather than a particular doctrine originally written on papyrus by shepherds who, in the Middle East, sought to give meaning to what they saw, creating their own Creation myths of the world and being human.

To measure more or less the size of the loss, when Christians incinerated the Library of Alexandria such a large amount of human knowledge has been lost, let’s take Sophocles (497 to 406 before our era), for example, we have only 7 of his dramas (Ajax, Antigone, The pesky Oedipus, Electra, Philoctetes and Oedipus at Colonus) although we know that he wrote over a hundred of them for references from other contemporary authors. The parallel with Shakespeare would be to - if their works were all destroyed and there remained only a few - we would know "The Merry Wives of Windsor", "Tales of a Summer Night" and "The Taming of the Shrew," with others unknown to us such as “Hamlet”, “Romeo and Juliet”, “Henry IV”, “Richard III”, etc..

Ptolemy (90-168 Before Our Era) lived in Alexandria and was a Roman citizen (lived in Egypt by the time Rome ruled virtually all around the Mediterranean Sea), curiously, much has been preserved, in particular his "Geography" and his "Apotelesmatika (which included knowledge about what we now call astronomy and astrology)." His Precious Work, however, was prohibited during the thousand years of darkness when Europe plunged over religious fundamentalism, as he proposed, for the first time, a heliocentric system, which was considered by the authorities of the time, a crime - the term used then was "heresy", but had the sense that today we understand the word "crime". Fluctuations of the language ...

As we saw, it took 14 centuries for Copernicus and Kepler - who exerted great influence on Galileo Galilei - the Ptolemaic system was reinstated and improved. Today, every child learns in his first letter that the earth is round, rotates around its axis, the sun is the center of the solar system around which the planets orbit, the Earth being one of them, etc.

Already the Greek question on evolution had to wait even five centuries after Copernicus, before Charles Darwin (1809 - 1882 of Our Age), after a Palingenesic voyage aboard the ship Beagle, reaching the Galapagos Islands, where he observed and collected an amazing amount copies of various animal species, some clearly intermediate to each other and did carry on ideas already postulated by Jean-Baptiste de Lamarck - (1744 - 1829) unconvincingly because Lamarck dared to include a series of scientific inaccuracies.



Lamarck vs. Darwin


Okay, the importance of Lamarck to the knowledge of Fact on Evolution should not be obliterated. Reached as far as, in his time and resources available to him, was possible. However, to conclude that variations between animal species are affected by the environment (not based on natural selection as Darwin postulated) made a mistake, but the idea that "species are interconnected and there are variations among them for some reason” was finally resurrected after centuries of darkness of religious obscurantism. Notice and never forget: even though slightly misguided in our innovative theories, we may be opening the door to more precise searches in the future. In science, the only thing to fear is dishonesty. If the scientific method is followed precisely (and may in some cases and under certain circumstances, be replicated) there is nothing to fear, even if we come to inconsistent conclusions at some point.

The classic example is still one of the giraffes that everyone knows but here we summarize again: Lamarck believed that to attain food - sprouts of trees - which were increasingly high, the giraffes were, over the generations “craning” and passing this trait on to future generations. Darwin's explanation is, instead, consistent with the scientific thinking and his analysis is confirmed by paleontological evidence. In the case of giraffes, those born with smaller necks (awkward to access food) simply perished and those who were born with larger necks survive and pass this trait on to future generations. Not yet known modern theories of genetics, but the rational observation allows us to see clearly how the pups resemble their generators: cubs, while growing, are very similar to their parents and have the same habits, instincts and characteristics. The same is true for primates that are persuaded to be the most evolved (you and I, for example), our offspring tends to be much like us. If a little human primate is born baring more resemblances with the milk deliverer than with her husband, the wife is in trouble, or both ;)



Darwin and Natural Selection


In the mid-nineteenth century, the Augustinian monk Gregor Mendel (1822 - 1884), and, besides the affairs of the Roman Catholic Church, he was also interested in plants and weather. His research in plant breeding led to the first reflection on what we now call “genetics” - but in his time, that knowledge did not come to Darwin and Alfred Russell Wallace (1823 - 1913), friend, scholar and enthusiast of evolutionism and foremost “accomplice” of the publication of the First Edition of “The Origin of Species by means of Natural Selection” in 1859. Darwin's wife was very religious - Darwin himself went through moments of crisis in this aspect with respect to a series of points of his new theory that contradicted the clearly inflated creationism in children in all Christian churches in the world - and would prefer that his work, of undeniable value, where published after his death. Wallace encouraged the publication of Darwin's work.

Well, we are in 2011, scientists have been able to map the human genome and we have extensive knowledge of how it is the process of DNA. We have advanced a lot in knowledge about evolution by natural selection over all these years.

Where in sexual reproduction, a new being is breed; half of its features are inherited from the male, and half the female of the species, thus creating a totally different but both of the same species and with the same habits, instincts and characteristics. Occasionally, a different combination generates mutations. Mutations with little chance of adapting to the world, quickly go extinct; mutations, however, better adapted to the natural environment that their parents tend to proliferate differentiating. Of course, this whole process takes a few thousands if not millions of years, so that you cannot reproduce it in the laboratory. However, the amount of evidence from all relevant areas of human knowledge to support this theory is overwhelming!

Paleontologists found in the oldest geological strata, fossils of extinct animals that today, however, retain similarities with their descendants who live and breathe today.

Zoologists and medicine doctors found the existence, in the species now living, some “useless survivor characteristics” obviously useful to an ancestor in the evolutionary process: Fin Whale that surprisingly resemble, in their bones, at the hands of primates, the human coccyx, evident reminiscence of the tail that the ancestral primate that gave rise to all contemporary great apes (chimpanzees, orangutans, gorillas, Homo sapiens ...); birds with wings that are no longer useful to the flight ... The examples multiply.



The Tree of Life


We do not know yet how inorganic matter made possible the emergence of life. Scientific research continues and progresses, but we can discard the myths that have been useful at the childhood of humanity (whether of Brahma who creates the universe by opening his eyes every 300 billion years them to close and allow Shiva to destroy it; that of the Indian of Brazil which released the night by opening a forbidden  coconut, that of Yahweh creating man of mud and woman from a rib) remain there with their poetic beauty but contribute nothing to scientific research – well, sometimes they even disturb it.

What we know, from all the evidence collected since the mid-nineteenth century to the beginning of this century is that all life originated in this world of one being able to reproduce itself. Over the ages, a phenomenon not very clear to the scientists raised the mating, amplifying the benefits of life, as part of the gene code comes from one parent and parts of the other, the next generation is more likely to mutate, and in many cases, mutations better adapted to their environment.

We also know that life originated in water, which over many ages came the fish, plus many thousands or millions of years and the first amphibians (creatures able to extract the oxygen they need to survive from the water or from open air, as certain species of lizards and frogs) and reptiles, including dinosaurs. The impact of a massive object (it is estimated that the size of Mount Everest, the highest mountain on earth) from space not only caused the extinction of the dinosaurs - not to mention an untold number of plants obliterated by a vast cloud of dust that encircled an Earth warmer than usual for several years - as about 90% of life then known, giving a chance to sort that made their first forays into the world but bared no chance while dinosaurs where still living: mammals.


Parenthesis - Impact of Asteroids and Mass Extinction Events


Here it is a digression, to deepen one pretty unique event: the impact of a celestial object of enormous proportions, causing mass extinction of life on Earth. For many years paleontologists know that some 65 million years the dinosaurs went extinct. In fact, there is not a single dinosaur fossil newer or younger than those dated 65 million years (there are several methods of dating ancient objects on the planet, and the Carbon 14's best known and accepted in the international academic community ). Many scientists have postulated that the impact of an asteroid or a comet of extraordinary dimensions would cause the extinction event that paleontologists reported, but there was no corroborative evidence to that up to the mid 70's, when a company prospecting for oil in the vicinity of the Yucatan Peninsula, near the village of Chicxulub, Mexico, found at the bottom of the sea, a crater 180 km; the object estimated to cause a crater that size is between 10 and 20 km A mountain high enough to cause an explosion equivalent to triple or more the entire nuclear arsenal ever produced by the entire human species at once. Sediments were removed from the site and compared with traces of other known impacts on our planet, and the same radioactivity signature found in other parts of asteroid impact on Earth was there too.

Finally, in March 2010, after extensive analysis of available evidence covering 20 years of data covering the fields of paleontology, geochemistry, climate modeling, geophysics and sedimentology, 41 international experts from 33 institutions reviewed all available evidence and concluded that the impact on Chicxulub triggered mass extinctions at the KT boundary (Cretaceous-Tertiary), including the extinction of dinosaurs.

Prova do Impacto que causou a extinção dos dinossauros

Needless to emphasize how much this has influenced the scientists and their reluctant supporters to step up the surveillance of Near-Earth Object (NEO - Near Earth Objects). For example, we know that on April 13, 2029 Asteroid named "99942 Apophis" or simply "Apophis", the name of an Egyptian god of destruction, will pass very close to the Earth, and if passed by a small area designated as "keyhole" that asteroid of 450 meters will come directly toward the Earth at its next orbit in 2036. There is time to prepare and think of a way to deflect it or destroy it. Or, as the ideologues of the world have preferred in recent decades, disregard this information and focus their attention on the capital market, leaving to future generations a big problem on their hands. 450 km will not cause a mass extinction event, but if it impacts us, can wipe out an astronomical amount of living organisms - including many humans - and destroy all our electronic communications system, among other drawbacks.


Close parenthesis - The Tree of Life – Deepening


Life, which first emerged in the water, one being at a certain time of about 4.5 billion years of existence on Planet Earth over the ages has evolved to be able to reproduce sexually and their offspring was adapting even be able to populate the Planet.

The genetic chain of all living beings (animals and plants) has the same basic features - they are based on chains of carbon and have a genetic code based on adenine, cytosine, guanine and thymine. What distinguishes us from a blade of grass or a lion is the amount and organization of the genetic code; the building blocks are precisely the same.

During an astronomically huge amount of time, a process over the animal and plant species have been - and continue! – differentiating itself, evolving. Surviving those who, by birth, are better adapted and succumbing those born with little or no chance of adapting to the environment.


Uncomfortable questions


For the scientist the most uncomfortable is not knowing (yet) exactly how inorganic matter are combined and/or suffered that kind of astronomical influences to become living matter. Again, research with eyes wide open is far more rational and dignified than the uncritical acceptance of ancient myths linked to the infancy of our species.

For the non-scientist, or even to someone who has genuine anger of those who rationally explain something which differs from scientific knowledge, a series of non-scientific questions arise. Let's explore some.

"If man descended from monkeys, how do monkeys still exist in the world?" - This question, more popular among religious fundamentalists, demonstrates an abysmal ignorance of the Theory of Evolution and the Tree of Life. Chimpanzees, orangutans, gorillas, and Homo sapiens have a common ancestor, but each of our species follows different direction. The same goes for dogs, horses, orchids ... All these species have a common ancestor but through the ages, the ancestral canine led the Wolf, The Jackal, the German shepherd ...

“The universe has less than 6,000 years old. You are in the Scriptures of Judaism, Christianity and Islam” (but not in the Vedas, which is more than 45,000 years old, of course) - this question usually is postulated by those who believe literally in a group of shepherds in search wrote to understand the world they lived in the Bronze Age. Usually are refractory to scientific knowledge but it is the challenge posited by Steven Weinberg: "And how do you explain the existence of oil on our planet?" - Everyone knows that oil is the result of decomposing organic matter under enormous pressure by a period of not less than 5 million years...


Extemporaneous sad note: a false controversy raised by fundamentalist American Protestants


The fanatical eagerness to find the god of Abraham in the beginning of all upset the minds of some scholars who have sought so eagerly but without any success – an irreducible complex structure. Evolution detailed and clearly explains how more complex organisms arose all from less complex organisms, so if it is a complex structure that is autonomous and not composed of pre-existing parts in other species, Darwin's theory would suffer a concussion.

The flagellum (a body which enables certain organisms to stick his entry into another, as a kind of biological drill) is the only example they could present. The problem is that the flagellum is composed of five different structures that exist in other species.

Dissatisfied, the creationists were right hair to U.S. courts to “teach the controversy” to the students. Nothing wrong on my part, frankly, but if we are to talk about the various mythological theories of creation when, in the infancy of mankind, we tried to explain the existence of the existing things, why should we cling to the Abrahamic theories when there are thousands of others, from the Eskimos to the Bushmen, through the millions of Hindus and Chinese theories with hair at least 40 millennia older than the Abrahamic? No. I think this just not fits in biology classes. Perhaps it is fitting in Philosophy, History of Philosophy, Comparative Mythology ...

To the amazement of many - myself included! - The U.S. Supreme Court decided that the scientific community must maintain its freedom to teach what the empirical data and the evidence found, prohibiting religious dogma dubbed "Intelligent Design" to be nailed in the classroom as if this conning religious propaganda were a sort of “alternative theory to evolution of species through natural selection.”

This kind of “debate” is still alive on the Internet, for example, but the score at the time of writing these lines is this: Fact of Evolution 1 x 0 Creationism).





Homo sapiens, primate superior, is the result of a long process of evolution and emerged, like all other primates, initially in Africa, migrating from there to all cardinal points of the world and in the process, acquiring appropriate adaptations to the places where he lives (skin with less melanin in locations with lower incidence of sunlight, stronger eyes in places subjected to high wind ...).

Our mental faculties allowed us, through the ages, to control fire, to develop spoken language (Noam Chomsky says that the human brain is a kind of  “hardware” born prepared for the spoken language; variations in language are due to different circumstances as where we live and the learning’s we get from our ancestors), to unite us against common enemies ... Throughout the ages, we become even able to domesticate animals and plants rather than being at the mercy of the uncertainties of hunting or collecting. When domesticated animals and plants formed the first human villages and we are now giving an introduction to our next chapter, which became known as the "Neolithic Revolution."

 Carl Sagan Explains The Evolution of Species


The Theory of Evolution Made Easy

Lazaro Curvêlo Chaves - May 7, 2010



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