The Origin of Species: Evolution and Natural Selection
Evolution is by definition:
Evolution is change in the heritable characteristics of biological populations over successive generations. Evolutionary processes give rise to biodiversity at every level of biological organization, including the levels of species, individual organisms, and molecules.
Natural selection is by definition:
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in heritable traits of a population over time. Charles Darwin popularised the term "natural selection". He compared it with artificial selection, which is intentional, whereas natural selection is not.
Darwin deducted from his work that:
All life forms find themselves submitted to a constant fight for life and for leaving the most amount of descendence. Also that this species are not fixed, they are constantly changing. Evolution and natural selection occurs over very long periods of time and variations between individuals are intrinsic.
There are other factors besides natural selection which affect the stability of species as well. These are mutations, genetic flow, genetic drift and genetic recombination.
Before Darwin there were other scientists who contributed to lay the foundations for the discovery of this natural law. Scientists like Georges Louis Leclerc, Georges Cuvier, Thomas Malthus and Jean-Baptiste Lamarck.
Despite all of this, it has been an unprecedented contribution to the life sciences and even other branch of science as well.
Which lead me to the following points:
Evolution promotes immoral behavior: That’s absolute nonsense. Most people who bring this kind of argument say that, because evolution it is based on the survival of the fittest, this implies that from this evolutionary perspective immoral and criminal behavior would be somehow justified. Survival of the fittest in the biological sense means the capacity for a given organism to adapt to a certain environment, survive and reproduce. Just as fish are adapted to live in water and birds are adapted to fly, we talk about fitness in the same sense. Evolution is just the biological mechanism that gives rise to new forms of life, to biodiversity as the definition says. It has nothing to do with our morality and empathy in that sense, which ironically, are now know to be natural, inherent characteristics in ourselves, granted by our process of evolution. They are part of complex social interaction, which is the reason why we have managed to get along so well or at least relatively well.
Evolution it has not been empirically demonstrated: Again, sheer nonsense. There a lot of evidence to prove the theory of evolution. There a countless fossil records where it can be observed the evolutionary process of the species, including ours. And there are other forms of evidence as well, like cases of artificial selection in pigeons and dogs. There also well known and studied cases of natural selection like giraffes and their tall necks for example. And also the known presence of vestigial organs which can only be rationally explained by this theory.
I really recommend you to read the book On the Origin of Species by Charles Darwin if you haven’t read it. There he explains clearly this theory and the ideas he had back then when he proposed it.
To conclude this post, i would also like you to see this youtube video in which is detailed about the reason why we know this theory is true. The video is quite long so watch it if you have the time or curiosity.
References:
Biological Sciences Theory by Yaditzha Irausquin. Editorial Actualidad.