Natural Selection

There are a couple of important points Darwin makes when considering his own argument of evolution through natural selection. Things like geographic distribution, the impact of man, and the types or heritable traits. Geographic distribution is something that plays a huge role in his theory of evolution. Two groups of the same species are separated by something like the mountain or the ocean. Over time these two species will develop and change the heritable traits that they pass on to their offspring. “The existence of closely allied or representative species in any two areas, implies, on the theory of descent with modification.” (Darwin 499) They need to do this to survive in their direct environment. Eventually over time both these groups of the same species will begin to resemble completely different species all together due to the traits they need to survive in their own environments. The traits that are passed down of course are the other factor to this equation. Most traits are heritable, meaning that they are passed down from generation to generation. Then these species often produce more offspring than can be sustained by their environment. They fight to stay alive and certain traits are continually passed down based on who has the most success in staying alive in their environment.

I think the most convincing argument is the relationship between geographical environment and barriers and species adapting to these environments. There are many species that are extremely like one another that live in two separate locations. They generally have adaptations that are needed to survive in the environment that they are living in. This is the part that seems almost irrefutable. These two groups that once possibly lived together have both survived in separate environments due to separate mutations that allowed them to thrive. The ability to change your traits based on surrounding is the best defense of natural selection.

One thought on “Natural Selection”

  1. You laid out Darwin’s arguments well. I also think you have a good discussion about them and I agree that adaptation is the fundamental aspect of natural selection. It really is where geography, genetics, and conscious actions of people come together. Your statement about two groups of a species living in an environment takes me back to Harari and the distinction between homo sapiens and neanderthals. What about Darwin’s arguments apply to this distinction? I think it is interesting that the change of a species’ traits is entirely dependent on their environment and it is the traits that produce the best chance of survival in this environment. However, the ability of man to manipulate their environment challenges natural selection as humanity takes the reigns in its own evolution.

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