"Biological evolution is just a theory or a fact? What if we ask someone on the street that is biological evolution?, We probably would more or less similar responses, some could be:
- Biological evolution is just a theory that monkey come
- is a process that improves the animals, humans reaching
is - as a theory that life began
The truth is that neither is correct, and if not expected, it happens that a theory and a fact at the same time! But how can this be?: In everyday life, the word theory means something like a guess, an idea about something not totally proven, but if it were shown, would cause a huge stir, as "theories" conspiracy Salfate .
Unfortunately, in science, the word "theory" means something radically different. In this, a theory is the highest degree of knowledge we can get on something (not forever, it can be replaced by another or simply refuted) is a mental construct that even allows to make predictions about the events studied under certain conditions, also should propose mechanisms to explain the "how" of the events studied. On the other hand, an act is simply an assertion, which would deny most chilling (Newton noted that apples fell, "denying it would be weird?). So, back to evolution, the truth is that it is a fact, a fact mainly studied by the branch of biology called "population genetics", but now the developmental biology has made great surprises (we'll discuss this another time .) Thus, biological evolution is:
"The variation in the frequencies of alleles (genes) in a population of individuals over generations"
Simply put, the fact of evolution is the change in the sampling of genes from a population of animals as they pass time, in fact, the term "allele frequency" or "allele frequency" is a term measurable mathematically models (long ago).
As mentioned above, a theory is the construct that explains the "how" of the facts, mechanisms and even make predictions. So, here is the "theory of evolution", which was originally postulated by Darwin (Actually next to Wallace), but since his nomination, has been enriched with all the new knowledge we have about genetics, molecular biology, embryology, etc. Forming a body of knowledge with great strength.
So what way the theory explains the "how" the fact of evolution?. To do this, proposed mechanisms, some proposed by Darwin and others more modern, some of which are:
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- Natural Selection Artificial selection (not applicable in nature, but to understand the origin of domestic animals)
Sexual Selection -
- Genetic Drift Genetic Recombination
- Genetic Drift
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- Horizontal Gene Transfer
- etc.
As you can see, since humans understood how genes work and the laws that govern inheritance (Darwin was not privileged), it was much easier to understand the evolution, as well as to integrate it into a major intellectual synthesis.
addition to this arsenal of mechanisms, many of which have been consistently confirmed in the laboratory, the theory can make predictions (also verifiable), such that it should look like an extinct animal, or what kind of fossils we should look at certain depths land (for this kind of predictions, biology takes her hand with geology).
As a final remark, note that the fact of evolution is never not try to explain how life originated on this planet (the theory does not cover this topic.) This is another fascinating subject, of which more later insurance.
