ST Lectures: The Evolution Of Sex

Question 1

What is Muller’s ratchet hypothesis?

Answer 1

1. In asexual populations, harmful mutations tend to build up irreversibly
2. Sexual recombination can get rid of deleterious mutations through sexual reproduction

Question 2

What is the red queen hypothesis?

Answer 2

Species must constantly adapt, evolve and proliferate in order to survive while competing with other evolving species in the same environment. This leads to an evolutionary arms race = must keep “running” just to stay in the same place

Question 3

What are the problems with sexual reproduction?

Answer 3

1. Finding a mate takes time and energy
2. Mates may demand additional resources
3. May be exposed to STD’s
4. Mating may prove an individual is infertile

Question 4

Why is sex considered a paradox?

Answer 4

Sex appears to serve the species at the expense of the individual. Asexually reproducing individuals could rapidly out compete sexual reproduction, but they do not.

Question 5

What are the two theories that can be used to explain the adaptive value of sex?

Answer 5

Muller’s ratchet and RQH