Evolutionary Genetics Flashcards
Infinite alleles model
- Each mutation creates a new allele in the population and can change into any other state
- All alleles are equally different from each other
Stepwise mutation model
-Mutation only changes allele to adjacent states
What type of mutations are selectively neutral?
silent or synonymous mutations
Muller’s ratchet
- asexuals organisms are subject to this
- deleterious mutations accumulate
Genetic load
presence of deleterious mutations
Natural Theory of Molecular Evolution
- Most single-nucleotide frequency changes are caused by genetic drift, rather than by selection
- Most mutations will become fixed or lost
- Positive selection rare, negative selection more common
Molecular Clock Hypothesis
If the rate of sequence evolution is driven by the rate of mutation, then genetic diversity can be used to date species divergence
k = u
Generation Time Hyposthesis
- mutations occur in germline
- faster generation times means more accumulated mutations in a shorter amount of time
Metabolic Rate Hypothesis
- mutations result largely from endogenous mutagens
- If they produce more byproducts because of higher metabolic rate, then faster accumulation of mutations
How do you calibrate the molecular clock?
- need to know the age of divergence/speciation
- fossil record dating
- Geological age of reproductive barriers
phylogeny-unweighted
all pairwise distances contribute equally
phylogeny-pair group
groups are combined in pair (dichotomies only)
phylogeny-arithmetic mean
pairwise distances to each group are mean distances to all members of that group
FOXP2
- major gene involved in AMH evolution
- transcription factor
- involved in development and function of brain
- mutated in speech/language disorder
srGAPS
- major gene involved in AMH evolution
- membrane bending protein
- involved in neurite outgrowth
