achilles - population genetics Flashcards
(23 cards)
What is at the center of the theory of evolution?
Adaptation to environmental conditions
The theory of evolution explains how species change over time through adaptation.
What are the three principles of natural selection?
- Principle of variation
- Principle of heredity
- Principle of selection
These principles explain how traits are passed on and how they affect survival.
What is the principle of variation?
Among individuals there is variation in morphology, physiology and behavior
This principle highlights the differences among individuals in a population.
What does the principle of heredity state?
Offspring resemble their parents more than they resemble unrelated individuals
This principle underscores the genetic connection between generations.
What does the principle of selection entail?
Some forms are more successful at surviving and reproducing than other forms in a given environment
This principle illustrates how certain traits confer advantages in survival.
What is the ultimate source of all genetic variation?
Mutation
Mutations can introduce new alleles into a population.
Are all mutations influential to natural selection?
No, most mutations are neutral, leading to molecular changes that do not offer advantages or disadvantages
Neutral mutations do not affect fitness and can accumulate over time.
What can indicate that selection has intervened in mutation rates?
If the rate of molecular changes is different than the expected rate of neutral changes
This may suggest that certain alleles are being favored or eliminated.
What does migration do in the context of allele variation?
Introduces alleles from one population to another with different ancestry
Migration can increase genetic diversity within populations.
What is linkage equilibrium?
The association between the alleles at two loci is random
In linkage equilibrium, allele combinations form independently.
What is linkage disequilibrium?
The association between the two loci is not random
Linkage disequilibrium can arise from new mutations.
What causes linkage disequilibrium to decline over time?
Recombination events
Recombination mixes alleles, leading to more random allele combinations.
What is genetic drift?
Change in allele frequency between generations due to sampling error
Genetic drift is a random process that can significantly affect small populations.
What happens to allele frequency if the population size is infinite?
Allele frequency remains the same from one generation to the next
Infinite populations are unaffected by genetic drift.
What is the probability that a self-fertilized offspring of a heterozygous individual Yy will be YY?
0.0625
This probability reflects basic Mendelian inheritance.
What is the founder effect?
Genetic drift resulting from the random sampling of the original population to create a new population
The founder effect can lead to reduced genetic diversity.
What is an example of the founder effect?
The reduced genetic diversity of Native Americans
This occurred due to a small population crossing from Asia to America.
What is a bottleneck in population genetics?
Period of population size contraction
Bottleneck events can lead to significant genetic drift.
What is natural selection?
The process by which individuals with certain heritable features are more likely to survive and reproduce
Natural selection drives evolution by favoring beneficial traits.
What is Darwinian fitness?
Ability of an organism to survive and reproduce
Fitness is a key concept in understanding natural selection.
What is absolute fitness?
Number of offspring
Absolute fitness measures reproductive success without comparison.
What is relative fitness?
Number of offspring/number of offspring of individual with the highest absolute fitness
Relative fitness provides a comparative measure of reproductive success.
What is a gene pool?
The sum of all alleles in the breeding members of the population
The gene pool is essential for understanding genetic diversity within a population.
