Evolutionary Animal Evolution

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The environment on earth is always changing and in order for organisms to survive they have to evolve in order to adapt to their surroundings (Dobzhansky 1973). As the environment changes it presents challenges to which organisms respond to by genetic changes that help them adapt to the new environment (Dobzhansky 1973). If the organism is not able to respond to the changes that it is presented with it can cause the organism to become extinct. An example of organisms adapting to their environment is an evolutionary arms race. In an evolutionary arms race both the predator and prey are constantly changing in order to compete with each other. If the predator did not adapt to the changes that the prey underwent the predator would go extinct and vice versa. This can also be referred to as coevolution, this is when two species genetic composition changes due to changes in another species and has affected their evolution. The predator prey relationship between the garter snake and the newt is a type of coevolution. Both the newt and the garter snake are constantly changing to out compete one another; this is an example of an evolutionary arms race. In order to understand adaptive evolution both genetic …show more content…
The evolution between the two will continue to happen unless one of the species no longer changes, this will cause the other species not to evolve because it no longer has to adapt to anything. In order for adaptive evolution to occur there has to be differences of tetrodotoxin resistance in the individuals as well as genetic variation (Brodie et al 1990). The continuous evolution of snakes with higher resistance is due to a high selective pressure on individuals with this capability. Garter snakes with the resistance trait have a higher survivorship and will be able to eat the toxic newts. Newts have also evolved in response of the snakes resistance to their