Darwin points out that with the changing environments, domesticated animals have varied, and that this same variance can be found under nature. Darwin argues that the more dominant groups beat the less dominant. He then lists off a few species with unintuitive adaptations, such as the woodpeckers ability to prey on insects on the ground, and upland geese which have webbed feet. He argues that natural selection is always ready to adapt the slowly varying descendants. Next, Darwin makes a great statement, that extinction inevitably follows on the principle of natural selection; for old forms will be supplanted by new and improved forms. Another excellent argument is that “The real affinities of all organic beings are due to the inheritance or community of descent. The framework of bones being the same in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse, etc…” I like to think of myself as one of the “young and rising naturalists” that Darwin is confident in! Darwin sums up his work nicely with the following statement: “I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number.”
Darwin comes across as very humble, questioning his own logic throughout the reading. This actually aids his arguments to be more convincing, for example when he says “It cannot be denied that we are as yet very ignorant of the full extent of the various climatal and geographical changes which have affected the earth during modern periods…” He acknowledges that we don’t have all the answers to life’s questions, and attempts to answer them using concrete evidence. Another example is on page 503. “Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. But analogy may be a deceitful guide.” Additionally, he places the objections to his theory before the special facts which support it, which tells me he accepts and encourages criticism. What is most convincing to me is the idea of shared instincts and traits, coming from common ancestors. Darwin argues against individual creation, saying “…[parent resemblance] would be strange facts if species have been independently created, and varieties have been produced by secondary laws.” Another convincing angle is how the intermediate steps are invisible. However, the evidence points to them existing. Ultimately, Darwin has inspired generations of scientists to question our beliefs and break new ground.