He states that there is a struggle for existence that species undergo which either causes them to adapt to survive or to become extinct . Darwin discusses how a large number of eggs or seeds is of some importance for some species who depend on a large amount of food and it also makes up for the destruction of a species at some period of life from natural disasters or some other event. So species might change their behavior in reproduction over time if they need to produce more eggs/seeds to give the species a better chance of survival. In addition , he talks about how intercrossing “plays an important part in nature in keeping the individuals of the same species, or of the same variety, true and uniform in character” (121). Similarly, he states that a species being in isolation helps it to become uniform by tending to modify all the individuals of a species in the same way since their conditions are the same. Since species must obtain certain behaviors and characteristics to survive it can be conclude that if they do not adopt then they risk the chance of decreasing or becoming extinct. He also discusses how variations have helped species to survive such as woodpecker’s beak, the parasite’s structure and the beetle’s ability to go into the water in order to get food. …show more content…
Darwin says that the diversity in the inhabitants of a region is an advantage for them similarly to the way that there is a division of labor in the organs of the body there is one in these diverse regions. Since all the different species have different habits of life it makes it easier for individuals to support themselves and survive. In contrast if there was little to no diversity it would be harder for animals to compete with other animals that have better adapted structures. However, competition among species could cause certain adaptation to occur in order for survival in a region and to make sure they can leave strong offspring so the species can continue to thrive. Darwin discusses how there is a struggle between males of species for the possession of females in order to leave offspring which is known as sexual selection. The males of a species can obtain certain characteristics that make them a stronger competitor than other males such as having a different structure, colour, or ornament caused by sexual