Lecture 20

Question 1

Co evolution

Answer 1

evolution of reciprocal adaptations of two or more species that have prolonged close interactions
Expect in mutualism (++), parasitism, predation (-+) and competition (–)
Unlikely in commensalism (o+) and amensalism (-o)

Question 2

Arms race

Answer 2

situations where an innovation one species leads to a counter innovation in the other

Question 3

What shifts adaptive peaks?

Answer 3

Biotic and abiotic world constantly changing

Question 4

Host pathogen interaction Flax Rust

Answer 4

Characterised R1 in plant and E1 genes in fungi
New mutation new pathogen in plant R1 low freq - strong selection for these genes so resisted pathogen and plants R1 at high freq, selection against e1 allele, mutated e1 ineffective r1 creating a sensitive plant, selection against r1 allele, resisted pathogen, sensitive plants, r! low freq and then selection for E1 etc.

Question 5

Mimicry

Answer 5

Mullerian mimics - exhibit reciprocal evolutionary patterns and have an opportunity to affect the evolution of each others colour patterns - depending on abundancy

Question 6

Batesisan mimicry

Answer 6

one palatable and one unpalatable - one has evolved and one has adopted this by dishonest signals

Question 7

Adaptive radiation

Answer 7

spread of new species of common ancestry intro different niches

Question 8

Covergent evolution

Answer 8

not closely related, independently evolve similar traits as a result of having to adapt to similar environments or niches

Question 9

Intrinsic factors

Answer 9

genetically controlled
metabolic and physiological opportunities
developmental opportunities

Question 10

Efficient dispersal

Answer 10

facilitates adaptive radiation

some organisms lack the ability to disperse over wide ranges, others can disperse much more widely

Question 11

intrinsic factors

Answer 11

empty habitats-lack of competition, novel environments, intensity of selection, founder effects

Question 12

ecological release

Answer 12

occurs when a species expands its niche within its own habitat or into a new habit where there is little competition for resources

Question 13

Streelman and Daniel. - general model of vertebrate evolution

Answer 13

Divergence of lineages into different major habitats.

2. Morphological specialization leading to trophic differentiation within habitats
3. Sensory communication diversification – sexual selection

importance of intrinsic factors but extrinsic factors shape radiation

Question 14

Evolutionary capacitance

Answer 14

a new theory stating that living systems have the ability to accumulate genetic variation that has no phenotypic effect until the system is disturbed (perhaps by stress). This mechanism permits rapid phenotypic change in a population, and rapid adaptation to new environmental conditions.

Question 15

Antarctic vs artic fish

Answer 15

them freezing

Antarctic fish produce glycoproteins

Arctic fish produce unrelated antifreeze proteins

Independent episodes of molecular evolution occurred, with the same functional results.

Question 16

Criteria to demonstrate adaptive radiation

Answer 16

common ancestry
phenotype environment correlation
trait utility
rapid speciation
link between key evolutationary innovation and rapid diversification

Question 17

Evolutionary relay

Answer 17

Independent species acquiring similar characteristics through their evolution in similar ecosystems, but not at the same time (eg dorsal fins of extinct ichthyosaurs and dolphins)

Question 18

Parallel evolution

Answer 18

Independent species evolving together at the same time in the same ecospace and acquiring similar characteristics (dolphins and sharks)

Question 19

Homologues

Answer 19

evidence of radiation

Question 20

analogous

Answer 20

evidence of convergent evolution