For each scenario, indicate which evolutionary process is most likely to be dominant.
1.
Genetic drift.
2.
Outbreeding depression.
3.
Directional selection.
4.
Stabilizing selection.
5.
Balancing selection.
6.
Disruptive selection
SCENARIOS
A) A population of rabbits is primarily preyed upon by coyotes. Only the fastest rabbits escape once seen.
B) In a population of cone snails, the individuals of the most common color suffer the heaviest predation.
C) In widowbirds, males with longer tails attract more mates, but also suffer higher predation.
D) Fledging success is highest among bluebirds with four or five eggs per clutch, although bluebirds lay two to seven eggs per nesting attempt.
F) Among a certain species of fish, both large males that defend high quality nest sites, and smaller males that resemble female fish fertilize many eggs.
G) A Puerto Rican parrot population was decimated by a recent hurricane. It appears that most birds within the path of the storm were killed.
H) In a population of sparrows, scientists noted that the sparrows killed in a particular storm were birds with much longer or shorter than average wings.
I) Fossil evidence indicates that the small, forest dwelling ancestor of modern horses gave rise to much taller (more recent) ancestors as the environment changed to grassland.
J) A population of solid gray ground snakes is well camouflaged on the rocky beaches of the island it occupies. Snakes born to island snakes that mate with the banded snakes from the mainland that occasionally arrive on the island are more likely to be eaten by birds.
K) In ground finches, both small beaked and large beaked birds have higher survivorship than those with intermediate beak sizes.
For each scenario, indicate which evolutionary process is most likely to be dominant.
| 1. | Genetic drift. |
| 2. | Outbreeding depression. |
| 3. | Directional selection. |
| 4. | Stabilizing selection. |
| 5. | Balancing selection. |
| 6. | Disruptive selection |
| SCENARIOS |
A) A population of rabbits is primarily preyed upon by coyotes. Only the fastest rabbits escape once seen.
B) In a population of cone snails, the individuals of the most common color suffer the heaviest predation.
C) In widowbirds, males with longer tails attract more mates, but also suffer higher predation.
D) Fledging success is highest among bluebirds with four or five eggs per clutch, although bluebirds lay two to seven eggs per nesting attempt.
F) Among a certain species of fish, both large males that defend high quality nest sites, and smaller males that resemble female fish fertilize many eggs.
G) A Puerto Rican parrot population was decimated by a recent hurricane. It appears that most birds within the path of the storm were killed.
H) In a population of sparrows, scientists noted that the sparrows killed in a particular storm were birds with much longer or shorter than average wings.
I) Fossil evidence indicates that the small, forest dwelling ancestor of modern horses gave rise to much taller (more recent) ancestors as the environment changed to grassland.
J) A population of solid gray ground snakes is well camouflaged on the rocky beaches of the island it occupies. Snakes born to island snakes that mate with the banded snakes from the mainland that occasionally arrive on the island are more likely to be eaten by birds.
K) In ground finches, both small beaked and large beaked birds have higher survivorship than those with intermediate beak sizes.
