Tuesday, October 15, 2019

Questions based on evolution and definitions Essay

Questions based on evolution and definitions - Essay Example Batesian mimicry which is a natural selection that favors the non-poisonous butterflies due to their similarity in their color with the poisonous butterflies is an example of a negative frequency-dependent. Positive frequency-dependency is seen in morph butterflies that are within the same species but have a different color pattern. Linkage disequilibrium arises when the genotype of at two loci is independent of each other and is as a result of Mutation, Random drift and Gene flow. It can be maintained by inducing mutation, random drift or gene flow in a generation. Deterministic forces are referred to as linear pressures due to their tendency to of pushing alleles frequencies in one direction which is either up , down or towards the middle. Important forces that take place in such a situation include selection, mutation, gene flow, meiotic drive and nonrandom mating. However, stochastic evolutionary force is the genetic drift that takes place due to random sampling of individuals and genes in small populations. Both are important because they lead to evolution as they cause changes in the genetic makeup of any population. The variance of reproductive success is usually higher among males than the females because the male sperm runs faster than the female, but dies faster than the female. The effect of this is more females in the society as a result of higher chances of having a female offspring. In situations when nonrandom processes overwhelm the random processes, it leads to low levels of variation which cannot be reconstructed over ecological time scales. Moreover, variation can arise from mutation and recombination. Since selection can remove variations from a population, genetic drift takes place. Antagonistic pleiotropy is a situation whereby the one gene controls foe more than one trait where at least a single of these traits

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