How do stabilizing and disruptive selection differ?
1.With stabilizing selection, the phenotype for a trait does not influence survival. With disruptive selection, the phenotype for a trait affects survival.
2. Stabilizing selection reduces the amount of variation in a trait. Disruptive selection increases the amount of variation in a trait.
3.With stabilizing selection, extreme individuals have high biological fitness. With disruptive selection, extreme individuals have low biological fitness.
4.Stabilizing selection produces adaptation. Disruptive selection is nonadaptive.
How do stabilizing and disruptive selection differ?
1.With stabilizing selection, the phenotype for a trait does not influence survival. With disruptive selection, the phenotype for a trait affects survival.
2. Stabilizing selection reduces the amount of variation in a trait. Disruptive selection increases the amount of variation in a trait.
3.With stabilizing selection, extreme individuals have high biological fitness. With disruptive selection, extreme individuals have low biological fitness.
4.Stabilizing selection produces adaptation. Disruptive selection is nonadaptive.
Related textbook solutions
Related questions
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.
Individuals in a population of fruit flies show variation in the number of bristles they have on their abdomens. Bristle number is a polygenic trait. The average bristle number is 40 with a low of 30 and a high of 50. An artificial selection experiment is begun where only individuals with greater than average bristle number are allowed to reproduce. After many generations of selection which of the following do we expect for the average bristle number?
| a. | it will be between 40 and 50 | |
| b. | it will be 50 | |
| c. | it will be greater than 50 | |
| d. | all individuals will have a bristle number of 50 |
