Test 2 Flashcards
(23 cards)
What is the definition of inbreeding?
An increase of homozygosity because mating occurs in closely related individuals
What is the inbreeding coefficient, and what does it mean?
F
The probability that an average individual has 2 “identical” alleles at a locus
What is the inbreeding formula? What does H stand for? What does 2pq stand for?
F = 1 - H/2pq
H is heterozygosity
2pq is the expected HW proportions
What is inbreeding depression?
The proportion of excess rare homozygous recessives (compared to an “outcrossed” population in HW proportions)
Describe the inbreeding depression formula in terms of words and alleles.
Inbred aa/Outbred aa
What is the simplified formula for inbreeding depression?
1+ pF/q
Using algebra simplify the inbreeding depression formula, given q2+pqF/ q2
q2+pqF/ q2 =
q(q+pF)/ q2 =
p+qF/q =
1+ pF/q
What is microevolution?
The change in allele/genotype frequencies over time in a population
What is the most severe form of inbreeding?
Self fertilization
Why doesn’t evolution occur during inbreeding?
Due to the decay in heterozygosity
Who are the only organisms mutation works for, in the sense of a mechanism of microevolution?
Prokaryotic and fast reproducing, haploid organisms
What does mutation do for a population?
Increase genetic variation
Define genetic drift.
A non-random sampling of parental gene pool due to small deme size
What does genetic drift lead to?
Sampling error (delta Q) and a loss of genetic variation (P)
The term deme is referred to as “population size,” but what else could it be referred to as?
A panmictic unit
Define panmixis.
All members of a group have equal access and are equally infertile with others (mating is random)
What is a metapopulation?
A group of spatially separated populations of the same species which interact at some level
What is the effective population size (Ne) equation?
And what do Nf and Nm represent?
Ne = 4NfNm/(Nf+Nm) Nf = females within the population Nm = males within the population
What are two things that can cause Ne to be smaller than the actual census (N)?
A skewed sex radio and an inequality in the number of offspring among parents
What are the four causes of genetic drift?
Founder effect
Population bottleneck
Population subdivision
Assortative mating
Which cause of genetic drift is this?
The population declines, almost to the point of extinction, and then recovers with a loss of genetic variation
Population bottleneck
Which cause of genetic drift is this?
N is very small
Founder effect
Which cause of genetic drift is this?
A violation of random mating (panmixis), producing almost the same results as inbreeding
Assortative mating
