The Three Types Of Disruptive Selection

The third type is disruptive, “Disruptive selection occurs when natural selection favors both extremes of continuous variation. Over time, the two extreme variations will become more common and the intermediate states will be less common or lost” (“Types of Natural Selection” np). For example, on a beach, dark and light oysters would have more options to conceal themselves: white beach sand and shadows from rocks (“Types of Natural Selection” np). The fourth type is kin selection, “Kin selection occurs when natural selection favors a trait that benefits related members of a group. Altruistic behaviors are a result of kin selection, and are best illustrated by animals with complex sociable behaviors” (“Types of Natural Selection” np). For instance,

“Charles Darwin conceived of evolution by natural selection without knowing that genes exist” (Laland et al np). Darwin did not understand that there is a different gene for every trait. “Darwin’s theory of natural selection lacked an adequate account of inheritance, making it logically incomplete” (Brian, Deborah np). If Darwin had an understanding of genetics and how genes work his theory would have been irrefutable. However the father of genetics, Gregor Mendel, discovered traits after Darwin published The Origin of the Species. Evolution starts at the genetic level, “These changes are produced at the genetic level as organisms’ genes mutate and/or recombine in different ways during reproduction and are passed on to future generations” (“Frequently Asked Questions…” np). Reproduction is the only way to pass on traits; the only way to change heredity is to change the genes. A new species is only classified as new if their heredity is different. “What matters is the heritable differences in traits, especially those that bestow some selective advantage” (Laland et al np). When species are striving to survive the organisms with the most advantages will be the ones allowed to pass on their traits and the organisms without advantages will eventually cease to

The theory of evolution also has a purpose in today’s world, more specifically in the study of organism’s immunity. Today antibiotics are very common, their main use is to get rid of viral infections. Although, scientists are finding, due to overusing antibiotics many viruses are becoming resistant to them. The more antibiotics get used the more bacteria and viruses become resistant to antibiotics and soon bacteria and viruses will resist all antibiotics. (“Frequently Asked Questions…” np). This is why, scientists study the evolution of bacteria’s immune system. Viruses mutate to develop plastids that resist antibiotics, this forces scientist to create new antibiotics. People are also guilty of using more than the needed amount of pesticides. “Similarly, the use of pesticides in agriculture has driven the evolution of resistant insects, requiring the use of harsher chemicals in greater quantity to kill them” (“Frequently Asked Questions…” np). The pesticides if distributed in larger quantities, may result in food containing too many chemicals and becoming harmful to humans. Scientists are creating new pesticides that can kill insects using lower quantities. Evolution is very visible in the medical field, especially when looking at the change in organisms like bacteria and viruses, and