Genetic Drift quiz #3 Flashcards
Genetic Drift quiz #3
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How do the founder effect and population bottleneck accelerate genetic drift, and what is the long-term impact on genetic variation?
The founder effect occurs when a small group establishes a new population, and the population bottleneck happens when a large population is drastically reduced in size. Both situations create small populations where genetic drift is strong, leading to rapid changes in allele frequencies and a long-term loss of genetic variation, even if the population later becomes large. What is genetic drift and how does it differ from natural selection?
Genetic drift is a random change in allele frequency due to chance, unlike natural selection which is predictable and based on fitness differences. Why is genetic drift more pronounced in small populations compared to large ones?
In small populations, random changes in allele frequencies are larger and more unpredictable, leading to greater effects of genetic drift. What happens to genetic variation in a population as a result of genetic drift?
Genetic drift reduces genetic variation because alleles can be lost from the population over time. How does genetic drift affect neutral alleles compared to alleles with fitness differences?
Genetic drift has the greatest effect on neutral alleles, but it can also affect alleles with fitness differences, sometimes increasing the frequency of deleterious alleles in small populations. What is the founder effect and how does it influence allele frequencies in a new population?
The founder effect occurs when a small group establishes a new population, causing the new population's allele frequencies to match those of the founders, often resulting in reduced genetic variation. Describe what happens during a population bottleneck and its impact on genetic drift.
A population bottleneck happens when a large population is drastically reduced in size, accelerating genetic drift and causing significant changes in allele frequencies. Can genetic drift lead to the fixation or loss of alleles in a population, and if so, how?
Yes, genetic drift can cause alleles to become fixed (frequency of 1) or lost (frequency of 0) in a population, especially in small populations due to random chance. Why might a large population have low genetic variation as a result of genetic drift?
If the population experienced a bottleneck or founder event in the past, genetic drift during the period of small population size could have reduced genetic variation, which persists even after the population grows. How do the founder effect and population bottleneck accelerate genetic drift, and what is the long-term impact on genetic variation?
Both the founder effect and population bottleneck create small populations where genetic drift is strong, leading to rapid changes in allele frequencies and a long-term loss of genetic variation, even if the population later becomes large.
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