Testing evolutionary questions with genomics tool

Question 1

Case study 1: horns on sheep-
Why do small horns persist on sheep when they have an obvious cost to male reproductive success

Answer 1

-Horns is determined by many genes of small effect and are just an indicator of quality (genic capture)

-Genes associated with small horns confer a fitness advantage in females (sexual conflict)

-Genes associated with small horns have some other benefit in males (trade off)

Question 2

What is the actual reason for short horns in sheep

Answer 2

Heterozygote advantage:
PP- males have poor reproductive success but good survival
++ - Have good reproductive success but poor survival
+P - Males have good reproductive success and survival

Question 3

Case Study 2: Genome sequencing and adaption (Darwin’s finches)

Answer 3

Major locus in beak shape: Fst estimated in 15KB windows, 6 of the 15 most differentiated windows were in loci known to affect craniofacial/ beak development.

A phylogenetic tree was made, most blunt beaks have homologous B

Question 4

What would you describe bill shape to be

Answer 4

Adaptive. Bills got blunter over time, selection favoured the species and bills would get blunter.
The B gene went into fixation

Question 5

Case study3: Evolution and maintenance of complex social behaviour (Fire ant)

Answer 5

Two forms: monogyne : single queen, BB allele
Polygyne: multiple queens, Bb allele

Question 6

How do the fire ant polymorphisms work

Answer 6

Caused by a super gene. The gene order differs between B and b, caused by an inversion

Question 7

What is a super gene

Answer 7

A number of tightly linked genes that are not affected by recombination

Question 8

What is social organisation controlled by

Answer 8

Non-recombining heteromorphic chromosomes