Lecture test 1: Hybrid zones

Question 1

Hybrid zone

Answer 1

Region in which members of different species mate and produce hybrids

Question 2

Where does a hybrid zone occur

Answer 2

A single band where adjacent species meet

Question 3

Example of a hybrid zone

Answer 3

Two species of toad of the same genus interbreed in a long narrow hybrid zone where their populations overlap (weak offspring produced-post zygotic barriers)

Question 4

Possibly outcomes of closely related species meeting in a hybrid zone

Answer 4

1. Reinforcement
2. Fusion
3. Stability

Question 5

Reinforcement

Answer 5

Reinforcing parent species, getting rid of hybrids, eliminate hybrid zones. Result in prezygotic barriers that will eliminate hybrid zone altogether

Question 6

Fusion

Answer 6

Hybrids as fit of fitter than parents. if gene flow is great enough parent species fuse into a single species

Question 7

Example of fusion

Answer 7

If the grolar bear proves to be more fit to survive with polar bear numbers going down, grizzly bears and polar bears will fuse to create the single species of grolar bear

Question 8

Stability

Answer 8

Continued formation of hybrids. Stability of hybrid zone.

Question 9

Example of stability

Answer 9

Parent species of Bombina routinely migrate to the narrow hybrid zone resulting in ongoing hybridization