Processes of Macroevolution

Question 1

List the four processes of macroevolution

Answer 1

divergent, convergent, coevolution and parallel

Question 2

Define divergent evolution and draw diagram to represent

Answer 2

the differentiation of distinctly different species (or populations) from a common ancestral species (or population)

refer to book for diagram

Question 3

Define adaptive radiation

Answer 3

rapid divergent evolution of a large number of related species from a common ancestor

Question 4

Define convergent evolution and draw diagram to represent

Answer 4

evolution through natural selection of similar features in unrelated groups of organisms due to similar environmental pressures

refer to book for diagram

Question 5

Define parallel evolution and draw diagram to represent

Answer 5

Occurs when related species evolve similar features independently

refer to book for diagram

Question 6

Explain coevolution

Answer 6

Species that interact closely exert selection pressures on each other. Both species therefore also experience the same environmental pressures. This results in two species evolving together in a reciprocal response to the various pressures

Question 7

Give an example of coevolution

Answer 7

Evident in predator-prey relationships. Once the weaker prey have been eliminated from the population, the predators need to evolve to be stronger and faster to keep up with the strengthening features of the prey.

Question 8

Explain how having high/low genetic diversity can lead to either species survival or species extinction.

Answer 8

A high level of genetic diversity allows populations to survive new or changing environments, which may lead to adaptation. Conversely, low genetic diversity increases the risk of extinction, as seen when species or populations go through a genetic bottleneck.

Question 9

Describe the bottleneck effect

Answer 9

Random events such as natural disasters, the allele frequencies are unlikely to represent the original population and genetic drift may occur. Reduced population sizes results in fewer reproductive pairings - leading to increased inbreeding (results in high numbers of homozygous individuals)

Question 10

What size population does the bottleneck effect have a larger effect on?

Answer 10

Smaller populations