EE Lecture 2: Genetics and Neutral Evoln Flashcards
why wouldnt blended inheritance work to explain natural selection
advantageous traits would be lost in the blending
what were main criticisms of darwins
blended inheritance would be advantageous traits would be lost in blending
darwins theory explain evoln as a process of chance but NS is a NON RANDOM process
gaps exist between forms in nature = gaps that dont make sense if orgs evolve gradually - directed evoln
why didnt gaps between forms in nature make sense in darwinian time
because darwin suggested that orgs evolved gradually, therefore gaps wouldnt exist, however gaps in fossils suggest directed evoln
what did Mendels pea experiments show about inheritance of genetic material
genetic material is particulate and doesnt blend
what is the modern synthesis of genetics based on
mendelian and darwinian theories
what is eqtn for hardy-weinberg eqbm
p^2+2pq+q^2=1
what is the effective popn size
Ne
total number of breeding individuals in a popn
what is the frequency of (A) in a diploid pop with 2 alleles, A and a
freq(A)=
A / 2Ne = p
what is the frequency of (B) in a diploid pop with 2 alleles, A and a
freq(B)=
B / 2Ne = q
what does p+q=?
1
WHAT are the condns necessary for the hardy-weinberg principle
popn infinitely large no mutation no gene flow no selection random mating
what is gene flow
exchange of genes between popns
migrating then mating
what is genetic drift
change in allelic frequencies due to random factors
small popn size=more genetic drift
what is the founder effect
type of genetic drift where allele frequencies are altered in small pops that are taken from larger pops
founders colonise a new region away from the parent group. over time all the members will be descents from the founders and their genes
a rare allele in the founding pop might become more common in later generations
when is a bottleneck caused
when there is a loss of genetic diversity after drift
