EVOLUTION
SOURCES OF VARIATION IN A POPULATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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less variation in the gene pool and survival is not affected
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Selective breeding, with enhanced chances of survival
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Natural Selection, with no impact on survival
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increased genetic variation and an increase in chance of survival
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Detailed explanation-1: -Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error). Genetic drift occurs in all populations of non-infinite size, but its effects are strongest in small populations.
Detailed explanation-2: -Migrants change the distribution of genetic diversity among populations, by modifying allele frequencies (the proportion of members carrying a particular variant of a gene). High rates of gene flow can reduce the genetic differentiation between the two groups, increasing homogeneity.
Detailed explanation-3: -Migration will change gene frequencies by bringing in more copies of an allele already in the population or by bringing in a new allele that has arisen by mutation. Because mutations do not occur in every population, migration will be required for that allele to spread throughout that species.
Detailed explanation-4: -Typically, mutations increase genetic diversity; the other three processes reduce it. Natural selection and genetic drift tend to enhance genetic differences among populations; migration tends to homogenize genetic difference, decreasing the differences among populations.