Multiple Loci: Linkage & Sex

Question 1

Advantages of asexual reproduction (4)

Answer 1

1. no waste time or energy finding a mate
2. produce more offspring
3. less costly/dangerous
4. maintains advantageous genotypes (linked genes)

Question 2

According to maynard smith’s null model, a population will maintain both asexual and sexual reproduction if: (2)

Answer 2

1. both modes produce the same number of offspring
2. the mode does not influence the offspring’s probability of survival

Question 3

what is two fold cost of sex

Answer 3

that sexual populations will grow half as fast as the asexual population (assumption 1 of maynard)

Question 4

assumption number 2 of maynard, why did they see increase in sexual vs. asexuals increase

Answer 4

because sexuals have recombination that increases fitness through crossing over and outbreeding

Question 5

recombination in meiosis with crossing over restores ______, random mating restores ____, and recombination increase ____ and improves ____

Answer 5

linkage equilibrium
HWE
variation and improves fitness

Question 6

What is the biggest benefit of recombination

Answer 6

it accelerates the rate of evolution because it creates beneficial mutations with different origins

Question 7

What is muller’s rachet

Answer 7

it is the accumulation of deleterious alleles and in asexual individuals it is passed down to offspring and accumulates with time.

Question 8

What can break muller’s rachet

Answer 8

sexual reproduction

Question 9

What are the 3 advantages of sexual reproduction

Answer 9

1. decrease muller’s rachet (deleterious mutations)
2. provides variability to survive in rapidly changing environment (adaptations)
3. recombination

Question 10

What is the red queen hypothesis

Answer 10

must run as fast as she can to stay in the race, in terms of hosts evolving defense against infection while parasites evolve mechanisms to evade defenses.

Question 11

Parasites adapt to what host type

Answer 11

the most common, therefore the rare host types are advantageous

Question 12

How does the red queen hypothesis example create LD and what results from it

Answer 12

selection creates LD because resistant to one parasite, then selects for the other parasite and causing missing genotypes, then sexual reproduction reduces LD and recreates the missing genotypes and maintain variation