Predators versus prey: evolutionary race

Beneta, Dijana (2009) Predators versus prey: evolutionary race. Bachelor's thesis, Faculty of Science > Department of Biology.

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Species while evolving must confront with the selective pressure. In order to evolve new adaptations they must go through genetic mixture, random fluctuation and mutation. The larger population has more chance to develop useful mutation because genetic fluctuations rely on probabilities and quantity. Individuales with useful genotype have competitive advantage. The predator species and prey species coexsist and develop together. The adaptations of predators and their prey reflect the result of an evolutionary arms race. Evolutionary arms race can get to extintcion of predator or prey population, or those comunities can coexist together with cyclic oscilations.The predator population size affect preys population size and vice versa. The higher evolutionary pressure is on prey population. Evolutionary arms race is battle between coevolution genes. It's an example of positive feedback. Experiments on predation by birds on cryptic prey show that crypsis (even slight crypsis) reduce predation and polimorphism in the prey population reduce search image. Predators learned to avoid noxious and brightly coloured prey. Experiments have confirmed that predators can learn to eject noxious pray faster if they are conspicuous rather than cryptic, but that kind of adaptation has advantages (mating ritual) and disadvantages (it is more noticeable). Parasitism is one form of predation (cuckoos and cowbirds nests). Acceptance of non-mimetic eggs by some hosts may reflect evolutionary lag or the costs of recognizing and rejecting parasite eggs. Most species during their lifetime are potential preys, even the biggest predators such as lions and wolves. The ultimate predators on planet earth are human beings because of their developed technology.

Item Type: Thesis (Bachelor's thesis)
Supervisor: Tadić, Zoran
Date: 2009
Number of Pages: 27
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Silvana Šehić
Date Deposited: 05 Dec 2014 13:36
Last Modified: 05 Dec 2014 13:36

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