FACTORS AFFECTING THE GENE POOL Flashcards
what is meant by the term “fitness” in biology?
The ability of an individual to survive and reproduce.
what is genetic diversity?
Genetic diversity is the variety of genes within a population. It helps species adapt to changes and survive diseases.
how does natural selection acts on a population: why is it sometimes referred to as “survival of the fittest”?
populations evolve through natural selection, where individuals with beneficial alleles are more likely to survive and reproduce, ones with less beneficial are less likely to survive - this is called “survival of the fittest’
what is the genetic drift?
changes in the allele frequencies of a population due to chance
what is the process of genetic drift and how does it change the make-up of the gene pool?
Genetic drift is the change in frequency of certain alleles within a gene pool between generations and is completely due to chance
what determines the effect that genetic drift has on the population?
it causes some alleles to increase in frequency while others decrease (mainly due to chance), in contrast, natural selection increases advantageous alleles and decrease bad ones due to processes of crossing over, independent assortment and meiosis.
what is migration?
Migration involves the movement of individuals from one population to
another.
whats the difference between immigration and emigration?
Emigration is the process of leaving a population while immigration is the process of joining a new population.
what effect does migration has on the gene pool of a population?
when individuals immigrate to a new population, their alleles add to a new gene pool and change allele frequency within the gene - when they leave they remove their alleles which reduces frequency in original population.
what is the founder effect?
The founder effect occurs when a small group from a larger population starts a new population, leading to limited genetic diversity and different allele frequencies compared to the original population.
what happens during the founder effect?
a small group from an original population leaves to form a new population, leading to differences in the gene pools of the 2 populations/similarities due to the small number of founders.
why does the gene pool of the founding population (the small group) is likely to be different to the larger population?
The founding population has fewer members than the original population, resulting in a smaller gene pool. This smaller pool is likely to differ from the larger gene pool because it represents only a small sample of the original population, leading to different allele ratios.
what is the bottleneck effect?
The bottleneck effect occurs when a large population significantly decreases in size due to an event, leading to reduced genetic diversity and changes in allele frequencies in the surviving population.
what happens to the size of the population during the bottleneck effect, what might cause this change?
During the bottleneck effect, a large population loss reduces the gene pool, leading to fewer alleles and random changes in allele frequency.
what are the effects the bottleneck effect has on the genetic diversity?
With a smaller population and fewer alleles, there is less genetic variation. This increases the risk of genetic drift and inbreeding, which can further reduce genetic diversity.
