And Man Created Dog

[SkyWriting]

When humans make the decisions on what individuals in a population get to breed on the basis of traits they find beneficial (such as the cows that produce the most milk and the chickens that lay the most eggs) it is no longer natural selection guided evolution, because it isn't environmental pressures that are guiding it but human breeders. Since humans can effectively prevent animals with undesirable traits from breeding (such as cows that produce little milk or chickens that lay few eggs) human guided evolution is very fast compared to what is seen in nature, but it can only work using the same essential principles that allow for evolution that happens all on its own. Technically, humans might become the first species that has a direct say in its own evolution.

Many species have played a role in their own extinction.
Again, how is any human behavior not a natural part of life?
If your saying that humanity is not natural, I agree. But why
would you say that?

If humans do not do natural things, then we are not animals.

 

[PsychoSarah]

Many species have played a role in their own extinction.
Again, how is any human behavior not a natural part of life?
If your saying that humanity is not natural, I agree. But why
would you say that?

If humans do not do natural things, then we are not animals.

I am not saying it isn't "natural" only that it is one species directing the evolutionary path of another rather than the natural environment in which they live alone. The key difference in human guided evolution versus natural selection is that we can actively prevent animals with certain characteristics from breeding (even if those characteristics wouldn't be detrimental to that in nature). This reduces genetic variation, which is why many domesticated animals are more prone to disease and genetic defects than wild ones.

I think you misunderstand the meaning of natural in this context. For humans, breeding animals for our use is natural, natural selection in this context means "through nature" as in through the environment as a whole, rather than human guided, which is where humans are the primary environmental force that dictates what traits are passed down to the next generation.