Chapter 23 Flashcards
Evolutionary change below the species level
Microevolution
What are the 3 main mechanisms that can cause change in allele frequency?
Natural selection, genetic drift, gene flow
Determined by a single locus with different alleles that produce distinct phenotypes
Discrete characteristics
Vary along a continuum along with a population
Quantitative characteristics
What are the 2 ways of measuring genetic variation in a population?
Gene variability and nucleotide variability
What are 3 mechanisms by which sexual reproduction shuffles existing alleles?
Crossing over, independent assortment, fertilization
A group of individuals of the same species that live in the same area and interbreed
Population
Aggregate of all copies of every type of allele at all loci in every individual in a population
Gene pool
1 allele exists for a particular locus in a population
Fixed alleles
Chance events cause unpredictable allele frequencies generation to generation
Genetic drift
Transfer of alleles into or out of a population due to the movement of their fertile individuals or gametes
Gene flow
A few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of the original population
Founder effect
The size of a population is reduced by a natural disaster or human action
Bottleneck effect
Contribution an individual makes to the gene pool of the next generation
Relative fitness
Both extremes survive and reproduce more successfully than others
Disruptive selection
