Darwin argues that natural selection is correct in a variety of ways, even though he couldn’t definitely prove it. He discusses how humans have the ability to create and manipulate these ideas, so why wouldn’t nature (pg.488). He also argues that birth happens at a much quicker rate than death, and there is a necessity for those who are more fit to live, to continue on their genetics, while those who are unable to survive die, and eventually that weak trait doesn’t live on anymore (pg.492). It is also important to remember that these genes that die out from the weaker species do not come back into the cycle, as they are detrimental to survival. He also argues that through domestication, we have altered the lives of animals, and they are on a new genetic track that may be altering to them (pg. 490).
The most convincing argument, in my opinion, was that if humans have the ability to manipulate reproduction and offspring, then nature would as well. This is an argument I had not thought of but find very interesting and applicable. Considering we come from nature, and adapted to this point where we can alter and control genetics, it would make sense that on some level nature allowed for this because of it leading us to where we are.