Coevolution

Question 1

What two things are involved in coevolution?

Answer 1

Coadaptation and cospeciation

Question 2

What is coadaptation?

Answer 2

When change in one organism causes the other to respond to that change

Question 3

What is the difference between something being infected vs infested?

Answer 3

Infected refers to an internal parasite, infested refers to external parasite

Question 4

What is the Red Queen hypothesis?

Answer 4

Hosts and parasites are constantly locked in an evolutionary arms race

Question 5

What is cospeciation?

Answer 5

When an original host species diverges into two species, the parasite also undergoes speciation

Question 6

What are the 3 options for a parasite once its host evolves?

Answer 6

1. Go extinct
2. Same parasite infects derived host
3. Undergoes speciation

Question 7

How can we tell if cospeciation has occurred?

Answer 7

Congruent phylogenies between parasite and host

Question 8

What is host capture?

Answer 8

Two hosts sharing similar niches allow one to contract the parasites of the other

Question 9

What is a parasite?

Answer 9

An organism living in or on another organism that causes damage to its host

Question 10

What is the parasite life cycle?

Answer 10

Hatch, find a host, get inside the host, extract nutrients to grow, reproduce, get offspring out

Question 11

What are the problems that parasites have during their life cycle?

Answer 11

Hard to find a mate, they tend to be R selected species and make tons of offspring

Question 12

What selection pressures are the hosts under?

Answer 12

Avoiding parasitism

Question 13

What selection pressures are the parasites under?

Answer 13

Evade host defences

Question 14

Which host genotypes will parasites evolve to exploit?

Answer 14

The most common ones

Question 15

Which genotypes will be selected for in the host?

Answer 15

The rare alleles that confer resistance to the parasite, so they become more common

Question 16

What will happen to the parasite when the host genotype conferring resistance to the parasite becomes more common?

Answer 16

The parasite evolves to exploit that genotype

Question 17

Despite all the problems associated with sexual reproduction, why is it advantageous?

Answer 17

Genetic variability

Question 18

Will a population that is parasitized choose to reproduce sexually or asexually more often?

Answer 18

Sexually

Question 19

What is toxoplasmosis?

Answer 19

A parasite that influences the behaviour of the host

Question 20

What are the 3 types of lice found on humans?

Answer 20

Head lice, body lice, pubic lice

Question 21

What phenomenon explains how body lice diverged off from head lice when we started wearing clothing?

Answer 21

Coadaptation

Question 22

What phenomenon explains how we acquired head lice?

Answer 22

Cospeciation

Question 23

How do we know that we acquired head lice through cospeciation?

Answer 23

Constructing phylogenies for the primates and lice lineages shows that head lice diverged off at the same time we diverged off from chimps, congruency

Question 24

What phenomenon explains how we acquired pubic lice?

Answer 24

Host capture from gorillas