Evolution Review
What is evolution
A change in allele frequency in a population over time
What is natural selection?
Organisms better adapted to their environment or more likely to survive and reproduce, which over time will select for these traits.
How many daughter cells are created, and how do they compare to the parent cell?
Four, genetically unique
A disease that kills 60% of adults in a population of deer is an example of what mechanism of evolution?
Genetic drift
What is gene flow, and how does it relate to evolution?
Genes/ alleles moving in or out of a population from immigration or emigration.
What is directional selection?
Selection for traits at one extreme but not the other
When does crossing over occur?
Prophase 1
What is fixation?
When there is only one of a certain allele present in a population
What is genetic drift, and how does it relate to evolution?
A random event that can change the alleles in the population (weather, illness, etc.).
What is stabilizing selection?
Selection pressure against phenotypes at extremes, selecting for the traits in the middle
How many copies of each chromosome are in the daughter cells at the end of meiosis?
1
What is microevolution?
All descendants are from the same species, and there are small changes in allele frequency over time
What is fitness?
What is disruptive selection?
Selection for traits at both extremes
What would the phenotypic frequency be for a BB x bb punnet square (B = brown fur, b = white fur)
100% brown fur
What is macroevolution?
Change at a species level, causing speciation to occur
What are two assumptions of the Hardy-Weinberg equilibrium?
- very large or infinite population
- random mating
- no natural selection (all phenotypes equal)
- no gene flow
- no net mutations
What are two criteria for natural selection?
- The trait has a genetic basis
- There is a variation in fitness
- The variation in fitness is related to the trait
What would be the genotypic frequency of a Bb x Bb punnett square (B = brown fur, b = white fur)
1BB, 2Bb, 1bb
What is the allele frequency for the G allele in a population with 6 GG individuals, 4 Gg, and 8 gg individuals?
0.44