1.7 Flashcards
What is the number one mechanism that drives evolution?
NATURAL SELECTION
What is another significant driver of evolution besides natural selection?
Mutation that creates new alleles
What is Genetic Drift?
A random change in the frequency of an allele in a gene pool
In which populations does Genetic Drift occur most easily?
Small populations
What can dramatically change the frequency of alleles in a small gene pool?
Chance mating or luck
Fill in the blank: Genetic Drift occurs when there is a ______ change in the frequency of an allele.
random
What happens when a changed group is reunited with the main population?
The two groups may now be too different for interbreeding
What is the phenotypic ratio for black fur in the sample of rabbits?
84%
What is the phenotypic ratio for white fur in the sample of rabbits?
16%
What is the genotypic ratio for BB in the sample of rabbits?
36%
What is the genotypic ratio for Bb in the sample of rabbits?
48%
What is the genotypic ratio for bb in the sample of rabbits?
16%
How many total alleles are in a sample of 25 rabbits?
50
What is the frequency of the ‘B’ allele?
60%
What is the frequency of the ‘b’ allele?
40%
Fill in the blank: In a small population, a random change to the allelic frequencies can occur for ______ reason.
no particular
What is the analogy used to explain random changes in allelic frequencies?
Flipping a coin
What does differential migration refer to?
The movement of a certain phenotype out of an area, decreasing allele frequency
What happens to the frequency of alleles when individuals emigrate?
Frequency DECREASES
What happens to the frequency of alleles when individuals immigrate?
Frequency INCREASES
What is population isolation?
Separation of a small group of individuals from the main group, leading to different allele frequencies
What can cause a disruption in the allelic frequencies of two different populations?
Gene Flow
What can act as a barrier that maintains two different gene pools?
Mountain, river, etc.
