In his last chapter, “Recap and Conclusion”, Darwin uses arguments of instincts, extinction, migration, and disuse to try and convince his readers of evolution through natural selection. First off, Darwin argues that instincts have been passed down through species of the common genus from a common parent. These instincts have come from natural selection and habits that the creature does through out its lifetime. Darwin uses the example of the architectural powers of a hive bee and how it knows how to follow roles and build hives. Darwin says, “If we admit that the geological record is imperfect in an extreme degree, then the facts as the record gives, support the theory of descent with modification”(Darwin 496). Shorty after this Darwin states again how creatures of the same species from different time periods have intermediates in between the present being to the common parent. These intermediate species have slowly developed traits that can be seen in the creature today, that were not found in the extinct version. He states, “For old forms will be supplanted by new and improved forms. Neither single species nor groups of species reappear when the chain of ordinary generation has once been broken” (Darwin 497). One of Darwin’s final arguments is disuse. Disuse refers to a creature not needing the use of an organ or extremity that it had once needed before. He uses the example of calf, which has inherited teeth that never come in. Natural selection has made these teeth unnecessary because the tongue or pallet became able to graze with out them.
I believe Darwin’s most convincing argument has to be the disuse of organs. Take for example wisdom teeth or our tailbones. Most humans no longer need their wisdom teeth and have them removed, much like Darwin’s example of calf’s teeth not coming in. Our tailbones used to serve a completely different purpose than the one it has today. Though the argument of disuse, one can clearly see how natural selection has effect many different species and how they have evolved to no longer need certain things. Darwin could not prove many of his arguments during his time, but I believe this argument could convince people of evolution.