Lecture 7 - Speciation

Question 1

What is adaptation?

Answer 1

Natural selection in response to the environment leads to increased frequency of a heritable phenotype in a population over time.

Question 2

What is acclimation?

Answer 2

It is a type of phenotypic plasticity in which a physiological response to the environment leads to the change of an individual phenotype during a single generation.

Question 3

What 3 situations cause hybridization to lead to speciation?

Answer 3

1. When hybrids produce more viable offspring
2. When hybrids are more fit than the original species
3. When hybrids become reproductively isolated

Question 4

What is reinforcement?

Answer 4

When hybrids are less fit, natural selection strengthens pre-zygotic barriers to reproduction, reducing the formation of unfit hybrids.

Question 5

What is fusion?

Answer 5

When hybrids are more fit than the original populations, reproductive isolation decreases.

Question 6

What is stability?

Answer 6

When hybrids are more fit in a specific time/place a hybrid zone is created and both species and hybrids continue.

Question 7

What evolutionary processes lead to reproductive isolation?

Answer 7

1. Natural selection
2. Genetic drift
3. Mutation

Question 8

What is punctuated equillibrium?

Answer 8

It is the rate of speciation at which a species undergoes little or no morphological change, interrupted by brief period of sudden change.

Question 9

What is the graduated model

Answer 9

It is the rate of speciation from the Darwinian view in which species diverge from one another slowly and steadily over time.