Topic 5: Individual Identity Flashcards
What is identity by descent?
Two alleles are identical by descent if they are descended from the same recent ancestral allele
Two alleles are identical in kind (state) if they have identical DNA sequences that did not come from descent
True or False
Alleles that are identical by descent will always be identical in state
TRUE
What is the probability that two offspring have two alleles that are identical by descent?
1/4
What is the probability that two offspring have 1 allele identical by descent?
1/2
What is the probability that two offspring have NO alleles identical by descent?
1/4
What is probability of identity?
The probability that one person in a population is identical at one locus to another individual in the population.
What is the probability that a random person in the population has the same genotype as you? (for homozygote and heterozygote)
Homozygote: pi^2
Heterozygote: 2pipj
What is the probability that a parent and an offspring are identical in state at one allele? (for homozygote and heterozygote)
Homozygote: pi
Heterozygote: (pi+pj)/2
What is the probability that one sibling is identical to another if the first sibling is a homzygote?
(1+2pi+pi^2)/4
What is the probability that one sibling is identical to another if the first sibling is a heterozygote?
(1+pi+pj+2pipj)/4
What operation do you use if you are finding the probability of an individual having the multilocus DNA profile?
multiply the separate locus probabilities together
How do you calculate average probability of descent?
You square all the genotype frequencies, sum all the homozygotes together and sum all the heterozygotes together
What is mark recapture a method for?
Estimating population size
N= number of individuals marked
p= proportion of marked individuals recaptured
T= total number of individuals in the population
p=N/T
