Lecture 12: Coevolution

Question 1

_____ & _____ now make up a large proportion of terrestrial species

Answer 1

insects & angiosperms

Question 2

coevolution definition

Answer 2

reciprocal genetic change in interacting species, owing to natural selection imposed by each on the other
–can also involve interaction between groups of individuals or gent elements within species

Question 3

coevolution can result from which 3 types of interaction s

Answer 3

-antagonism (e.g. predation, parasitism) (+/-)
-competition (-/-)
mutualism (+/+)

Question 4

antagonistic interactions: which hypothesis?

Answer 4

• red queen hypothesis
• -spp. A evolves adaption in response to spp. B
• spp. B evolves adaption in response to spp. A
• -parasitism & disease

Question 5

antagonism herbivory:

Answer 5

• costly to plant
• -regenerate lose parts or have less leaf area
• evolved defences:
• -thorns/spines
• -toxins
• -visual cues

Question 6

antagonism herbivory example:

Answer 6

Passionflower vine shave toxin (cyanogenic compounds) in their leaves
-Heliconius caterpillar can detoxify & disable these AND use them for their own defence against predators

Question 7

competition: sometimes one species ____ others and drives them to extinction

Answer 7

out competes

Question 8

sometimes competition results in adaptions that ___ competition - helping the species to co-exist

Answer 8

REDUCE

Question 9

scenario for competition to occur:

Answer 9

• 2 species with significant overlap of niches
• over time, those individuals competition experience less success. NS drives each species to greater speciation, partition the resource

Question 10

resource partitioning may be accompanies by

Answer 10

character displacement.

-when in sympatry traits differ more so less competition

Question 11

mutualism does not mean no

Answer 11

conflict

Question 12

mutualism can lead to antagonism

Answer 12

nectar robbers –> as don’t pollinate, just steal!

Question 13

Mullerian mimicry:

Answer 13

Heliconius species have evolved bright colour patterns to advertise their toxicity to predators
-several other species have the same pattern, all benefit by sharing cost of educating predators
(all acc toxic)

Question 14

coevolution below the species level:

Answer 14

• Sexually antagonistic coevolution (SAC)

- coevolution between genes in the genome

Question 15

sexually antagonistic coevolution

Answer 15

Arms race between the sexes

Question 16

coevolution between genes in the genome

Answer 16

• mutualistic (coevolved gene complexes)

- antagonsitic (genomic conflict)

Question 17

how is SAC a case of genomic conflict?

Answer 17

• most differences between the sexes (sexual dimorphism) are produced by differences in expression of AUTOSOMAL GENES (sex biased gene expression)
• genes that show sex biased expression can have different evolutionary rates
• could be indicative of SS/SAC

Question 18

abiotic influences produce ___, but biotic interactions are probably more important for generating ___

Answer 18

–adaptation

–Diversity (speciation)

Question 19

fitness is an interaction between the ___ and the ____:: the biotic environment is itself _______

Answer 19

Fitness is an interaction between the GENOTYPE and the ENVIRONMENT: the biotic environment is itself CONSTANTLY EVOLVING

Question 20

coevolutionary dynamic can rapidly influence

Answer 20

traits

Question 21

ways of studying coevolution:

Answer 21

• Models
• -parasitism
• Observations
• -phylogenetics
• Experiments
• -e.g. competition between caterpillar, learning leaf shape

Question 22

adaptation passiflora (passionflower) to reduce caterpillar herbivory damage and caterpillar counter-adaption

Answer 22

• passiflora have egg mimicry
• and secrete nectar from their leaves to attract ants and wasps so they feed on caterpillar
• also have leaf shape variation to escape detection
• -caterpillar can learn leaf shape