Unit 8: Pedigree Analysis

Question 1

What is inbreeding depression

Answer 1

The reduction in fitness of progeny from mating between related individuals, compared with the fitness of progeny between unrelated individuals

Question 2

What can be used to provide inbreeding information in a population in the absence of molecular data

Answer 2

Data from genealogies or pedigrees, as long as complete pedigrees are available.

Question 3

What does the inbreeding coefficient(F) refer to

Answer 3

It refers to the expected increase in homozygosity in inbred individuals compared to the non-inbred population, and the corresponding decrease in heterozygosity.

Question 4

What is the range of F ( in breeding coefficient) and what does it mean

Answer 4

The range is 0 -1
0 being non-inbred and 1 being in-bred

Question 5

What are autozygous individuals

Answer 5

Individuals who have 2 alleles that can be traced to be from a common ancestor
These alleles are identical by descent (IBD)

Question 6

What are allozygous individuals

Answer 6

Individuals who have 2 alleles descended from different ancestors

Question 7

What does the pedigree inbreeding coefficient indicate

Answer 7

It indicated an individuals probability of being autozygous

Question 8

Explain the example of studying inbreeding coefficient in Callimico Monkeys

Answer 8

• They studied the correlation between inbreeding coefficient and infant survival in callimico monkeys
• There was a negative correlation between the inbreeding coefficient and the % infant survival
• F=0 related to 75% survival
  F=0.125 related to 65% survival
  F= 0.250 (full siblings) related to 20% survival