Coevolution

Question 1

What is coevolution?

Answer 1

occurs when two species evolve in response to each other

Question 2

Is it coevolution when one or more organisms evolve in response to their abiotic environment?

Answer 2

NOT COEVOLUTION

Question 3

What is this an example of:

Lizard populations that experience regular hurricanes have evolved the adaptation of increased to pad size, as those with smaller toe pads get blown off trees during hurricanes and die.

Answer 3

REGULAR evolution NOT coevolution

Question 4

Example of coevolution occurring between plants and pollinators.

Answer 4

Dwarf hammer orchids have evolved to mimic the smell, size, shape, and color of a female thynnid wasp. Male thynnid wasps inadvertently spread pollen between orchids, while (unsuccessfully) attempting to mate with the plants.

Question 5

Example of coevolution occurring between plants and herbivores.

Answer 5

Adult monarchs drink milkweed nectar and lay eggs on underside of leaves. Monarch caterpillars are herbivores of milkweed leaves. Milkweed has developed different defenses.

Question 6

What are the three defenses milkweed has coevolved to protect themselves against caterpillar herbivory?

Answer 6

1) Hairs (trichomes) on the leaves, that prevent monarch caterpillars from being able to reach the leaves.
2) A latex toxin that is exuded by the leaves when bitten, that can cover and kill the caterpillar (like glue).
3) Cardiac glycoside toxin in the plant tissue itself.

Question 7

How do monarch caterpillars ‘counter’ each plant defense?

Answer 7

1) Hairs (trichomes) on the leaves, that prevent monarch caterpillars from being able to reach the leaves.

• they just bite the trichomes off

2) A latex toxin that is exuded by the leaves when bitten, that can cover and kill the caterpillar (like glue).

• they do a behavior called the ‘vein drain’ they bite the leaf further up so that the latex seeps out of the stem and no longer reaches the plant tissue

3) Cardiac glycoside toxin in the plant tissue itself.

• they have genetically determined tolerance to the toxins, as compared to species that do not eat milkweed

Question 8

What do monarch butterflies do with the milkweed toxins?

Answer 8

store the milkweed toxins they consumed as caterpillars through their chrysalis and adult phases to make adult monarchs distasteful to predators

Question 9

How did the Tasmanian devil populations coevolve to devil facial tumor disease (DFTD)?

Answer 9

over time, the frequency of early sexual maturity and early breeding increased in Tasmanian devil populations that had high rates of infection with devil facial tumor disease