Co-evolution

Question 1

What causes Co-evolution?

Answer 1

• When species often interact with each other
• Occurs when selection pressure on one species are influenced by the evolution of another

Question 2

Inter-specific competition

Answer 2

• Two competing species may partition resources
• Character displacement in Sympatry (together) habitats

Question 3

Mud snail case study

Answer 3

• Two Mud snails Ulvae (U) and Ventrose (V) are examples of interspecific competition
• They both injest substrate and bacteria
• In Allopatric locations, they have same size shell and diet.
• In Sympatric locations, U is much larger and eats larger substrate than normal

Question 4

Cuckoos background

Answer 4

• Cuckoos are brood parasites
• Reed warblers are their favourite hosts which lays 4-5 blue brown eggs
• Cuckoos may lay up to 15 eggs a season
• Chicks hatches ealy and removes competition by pushing the host egg out of the nest.

Question 5

How are cuckoos linked to evolution?

Answer 5

• Strong selection on host to reject cuckoo
• Strong selection on cuckoo to fool host
• Female cuckoos specialise in one species and lay relating eggs
• Mimicry evolved as a result of host discrimination
• Dunnocks do not discriminate as they are evolutinoary new hosts

Question 6

Cuckoo adaptions

Answer 6

• Egg mimicry, shell hardness
• Fast laying behaviour, lays when host is laying
• Chick hatches early and removes young
• Chick mimics host offspring

Question 7

Mutalism

Answer 7

• Co-evolution through mutally positive association
• E.g. bees and flowers

Question 8

Indirect co-evolution

Answer 8

• Insect Aposematism
• Where insects mimic posionous species to prevent being eaten