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The Theory of Evolution Explained For Beginners | Evolution biology

Every February 12th we celebrate Darwin's Day. Why? It is the date when the one who is considered the father of the theory of evolution was born. 

Darwinian Theory of Evolution.
Darwinian Theory of Evolution.
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That is why, all over the world, thousands of institutions, collectives and individuals do something to celebrate the incredible work of this naturalist hundreds of years ago.

What is the theory of evolution?

The theory of evolution is how a corpus is known, that is, a body of knowledge and scientific evidence that explains a phenomenon: biological evolution. 

It explains that living beings do not appear out of nowhere and for no reason, but that they have an origin and that they change little by little. At times, these changes cause two distinct species to emerge from the same living being, or ancestor. 

These two species are distinct enough to be recognized separately and without doubt. The gradual changes are known as evolution, because the living being changes towards something different.

Evolution is mediated by something generally called "natural selection," although this term is very vague. A more correct term is selective pressure.

The same is true of the theory of evolution, which explains that living beings do not appear out of nowhere and why. This name is understood to mean a factor that "pushes" these changes in one direction. 

For example, the dryness of a desert will put pressure on all species to be more resistant to dehydration, while those less adapted will perish and be lost to history. 

Evolutionary changes, as we can already deduce, are often adaptive in a very rough way, which means that they adapt to the selective pressure on a species (or make it disappear forever). 

The theory of evolution is far from simple and has grown enormously over the course of the history of biology. 

Today, this body of work is so large that it is being studied in a number of different ways, and there are specialists who are dedicated exclusively to understanding very specific parts of the theory.

When did it appear?

The origin of the theory of evolution has a specific date and is the publication of the book "The Origin of Species" by Charles Darwin himself. 

Although in reality the idea of evolution and various related concepts can be traced back to much earlier times, the truth is that the controversial publication of his book provoked an unparalleled reaction. 

To this day, this text clearly laid the foundation around which the basic "axioms" with respect to all aspects of biology. That was on 24th November 1859. 

In this book, Darwin explained his hypothesis (which had been greatly tested and proven since then) as to how living species evolve and how natural selection (and selective pressure) drives such change.

Where was it originated?

Although "The Origin of Species" was published in England, the fact is that the emergence of the theory of evolution came much earlier than that. Historians place this moment in Darwin's travels aboard the "Beagle," a British explorer. 

On his second mission, the young Darwin was added to the crew, whose education and interest in geology and nature, as well as some family interests, opened the door to his passage. 

During his trips around the world (literally), which lasted five years, Darwin acted as a naturalist (the classic concept of a biologist) collecting all kinds of information for the English empire and the crew. Thus, during the voyage he came across several islands and their species. 

The modifications and characteristics of these, as well as his geological knowledge and the influence of several acquaintances instilled in his mind the idea of evolution in living beings. Especially striking is the case of the finches of the Galapagos Islands, which are very prominent in the literature. 

However, it took several decades for the idea to mature, which finally, and not without many dilemmas and some tragedy, resulted in "The Origin of Species", the seed of the theory of Evolution.

Who proposed it?

Well, it's obvious, at this point, that the father of the theory of evolution was Charles Darwin. We've been able to prove that so far. But we owe the theory not only to him, let alone its current state. 

Leaving aside some classics, it would be unforgivable not to mention Alfred Russel Wallace, a naturalist and geographer, as well as an explorer very similar in spirit to Darwin. His more modest position than Charles probably put him a few steps behind the father of the theory of evolution. 

However, Wallace himself came to similar conclusions to Darwin even before he did. It was a letter from him that finally put the ideas into the head of the most famous naturalist in history.

Thus, this letter from Wallace was decisive in its publication on the subject. However, that does not detract from the merit of Darwin. On the other hand, it would also be necessary to name Lamarck, since he proposed the first theory of evolution as it is known today. 

The theory was wrong, but this has not prevented debates that are still going on today. 

Later other great scientists laid some necessary foundations: Georges Cuvier and √Čtienne Geoffroy Saint-Hilaire discussed extensively about catastrophism and uniformitarianism; Mendel and, years later, Fisher laid the genetic and statistical foundations essential to the theory; Avery, MacLeod and McCarty found deoxyribonucleic acid; and Francis Crick and James Watson, thanks to the work of Rosalind Franklin, discovered the structure of DNA. And these are just some of the names to which we could claim to thank for the theory of evolution


Perhaps the most difficult and yet most simple answer to give. Why did the theory of evolution appear? We can look for historical reasons, consequences: Darwin watching a few birds on a remote island or Watson and Crick discussing a strange black and white photograph pensively. 

But the truth is that the theory of evolution appears as a consequence of observation. 

Over the centuries, over the millennia, we've seen living things change. What's more, we use this fact to our advantage. So it was only a matter of time before someone would figure out how. 

After centuries of observation and experimentation, the theory of evolution is what we've accomplished. But we're not finished yet, and it isn't complete. Some aspects of it we'll probably never fully understand. 

In any case, the answer to the question of why the theory of evolution appeared will always be the same: because we need to know where we come from; and where we are going.