Lecture 18 - Adaptation II

Question 1

what is co-evolution?

Answer 1

the evolution of reciprocal adaptations of 2 or more species that have prolonged close interactions

Question 2

where is co-evolution expected?

Answer 2

in mutualism (where both species gain something), parasitism/predation (one species gains/one species loses) and competition (cost to both species)

Question 3

where is co-evolution not expected?

Answer 3

commensalism and amensalism (one species has gain/loss but the other species doesn’t care)

Question 4

what is the red queen hypothesis?

Answer 4

each species is engaged in a permanent race with another but success for one inevitably means decline for another

Question 5

what is an arms race?

Answer 5

innovation in one species leads to counter innovation in another

Question 6

why do Mullerian mimics exhibit reciprocal evolutionary patterns?

Answer 6

both species are unpalatable and therefore affect each others colour patterns: when the more abundant species becomes less abundant they change their colour to be predated less

Question 7

why may Batesian mimics no exhibit co-evolutionary phenomena

Answer 7

one species is palatable so one copies the other to make them both APPEAR unpalatable

Question 8

what is adaptive radiation?

Answer 8

the spread of a new species of common ancestry into different niches involving an excess of cladogenesis over extinction

Question 9

what is cladogenesis?

Answer 9

the splitting of one lineage into 2+ evolutionary independent new lineages

Question 10

what intrinsic factors promote adaptive radiation?

Answer 10

metabolic, developmental and physical opportunities

Question 11

what extrinsic factors promote adaptive radiation?

Answer 11

empty habitats (no competition), new environments, intensity of selection, founder effect

Question 12

what is convergent evolution?

Answer 12

organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments/ ecological niches

Question 13

what is an example of molecular convergent evolution?

Answer 13

Antarctic and Arctic fish both producing antifreeze to stop them from freezing

Question 14

what homologous structures evidence of?

Answer 14

adaptive radiation (limbs of mammals)wh

Question 15

what are analogous structures evidence of?

Answer 15

convergent evolution (wings of birds and insects)

Question 16

what are the limitations of convergent evolution?

Answer 16

contingency (something that happened in the past), functional/physical, developmental or genetic constraints