KA 2 Flashcards
What is evolution?
It is the change over time in the proportion of individuals in a population differing in one or more inherited traits
During evolution, changes in allele frequency occur through what 3 processes?
The non-random processes of natural selection and sexual selection, and the random process of genetic drift
Natural selection acts on?
Genetic variation in populations Variation in traits arises as a result of mutation.
Mutation is the original source of new?
Alleles
New sequences can be what kind of alleles?
Novel alleles.
Most mutations are? But in some cases they may be?
Harmful or neutral, but in rare cases they may be beneficial to the fitness of an individual.
Populations produce …. Offspring than the environment can support
More
Individuals with variations that are better suited to their environment tend to?
Survive longer and produce more offspring, breeding to pass on those alleles that conferred an advantage to the next generation.
Selection results in the?
Non-random increase in the frequency of advantageous alleles and the non-random decrease in the frequency of deleterious alleles.
Sexual selection is the?
Non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring
Sexual selection may lead to?
Sexual dimorphism
Sexual selection can be due to?
Male-male rivalry and female choice
What is male-male rivalry?
Where large size or weaponry increases access to females through conflict.
Female choice involves?
Females assessing the fitness of males.
Genetic drift occurs when?
Chance events cause unpredictable fluctuations in allele frequencies from one generation to the next
Genetic drift is more important for what kind of population?
Small populations, as alleles are more likely to be lost from the gene pool
Population bottlenecks occur when a?
Population size is reduced for at least one generation.
Population size is reduced for at least one generation.
Population size is reduced for at least one generation.
Founder effects occur through the?
Isolation of a few members of a population from a larger population.