Chapter 23: Evolution Flashcards
What can cause allele frequency(microevolution)?
natural selection, genetic drift, and gene flow
What is genetic variation?
Differences in genes or other DNA segments in individuals
Does nucleotide variation result in phenotypic variation?
No
What is a point mutation?
Change in one base in a gene
What are some effects from point mutations?
Result in a change in protein production(GOOD OR BAD), be hidden in recessive alleles
What is neutral variation?
No selective advantage or disadvantage
What are some conditions for non-evolving populations?
- no mutations
- random mating
- no natural selection
- large population size
- no gene flow
What is adaptive evolution?
An improvement in the match between organisms and their environment
What is genetic drift?
How allele frequencies fluctuate unpredictably from one generation to the next. Reduces genetic variation through loss of alleles
What is the founder effect?
When individuals become isolated from a larger population
What is the bottleneck effect?
The sudden reduction in population size due to a change in the environment
What is gene flow?
Movement of alleles among populations. Alles can be transferred through the movement of fertile individuals
What happens to variation from gene flow?
Reduce variation among populations over time
