Natural Selection

Question 1

Principles of Natural Selection

Answer 1

1. natural selection depends on the environment. It does not favor the superior trait but favors the traits that are beneficial for survival and reproduction in a specific area.
2. natural selection acts on the existing heritable traits. This heritable variance serves as a starting material for natural selection to act upon.
3. heritable variations come from random changes or mutations in the genes.

Question 2

Four fundamental principles of natural selection that Charles Darwin originally outlined in his book The Origin of Species

Answer 2

1. Variation
2. Inheritance
3. High rate of population growth
4. Reproductive advantage

Question 3

variables which cause a certain phenotype of an organism to have a better chance of surviving and reproducing.

Answer 3

selective pressures

Question 4

a particular way that genes are expressed in the physical traits or characteristics of an organism

Answer 4

phenotype

Question 5

3 types of natural selection

Answer 5

1. stabilizing selection
2. directional selection
3. Disruptive Selection

Question 6

This type of natural selection occurs when there are selective pressures working against two extremes of a trait and therefore the intermediate or “middle” trait is selected for.

Answer 6

Stabilizing selection

Question 7

This type of natural selection occurs when selective pressures are working in favour of one extreme of a trait.

Answer 7

Directional selection

Question 8

This type of natural selection occurs when selective pressures are working in favour of the two extremes and against the intermediate trait. This type of selection is not as common.

Answer 8

Disruptive selection

Question 9

External forces which affect an organism’s ability to survive in a given environment.

Answer 9

selective pressures

Question 10

a measure of the extent to which natural selection is acting to reduce the relative contribution of a given genotype to the next generation.

Answer 10

selection coefficient

Question 11

describes a difference in relative fitness between one genotype and another standard genotype.

Answer 11

selective coefficient