Sexual Selection

Question 1

Sexual dimorphism

Answer 1

The differences in appearance between males and females of the same species.

Question 2

Sexual Selection

Answer 2

It is a special type of natural selection that favours traits that specifically enhance the mating success of an individual.

It is even powerful enough to produce features that are harmful to the individual’s survival. For example, extravagant and colorful tail feathers are likely to attract predators as well as interested members of the opposite sex.

Question 3

Tug of War

Answer 3

If natural selection pulls too hard, then it will be hard to mate

• If sexual selection pulls to hard it will be hard to survive
• Nature often finds a balance

Question 4

Intrasexual Selection

Answer 4

• Refers to competition between members of the same sex (usually males)
• Direct competition
• Example: Male deer fight over a female

Question 5

Intersexual Selection

Answer 5

• Refers to when members of one sex (usually females) choose which members of the opposite sex to mate with.
• Indirect competition
• Example: Birds of paradise dancing

Question 6

Natural vs Sexual Selection (Provide Examples)

Answer 6

Natural Selection:
Individuals with advantageous traits are more likely to survive and pass on the genes of the advantageous traits.

Sexual selection:
It is a special type of natural selection that favours traits that specifically enhance the mating success of an individual.

It is even powerful enough to produce features that are harmful to the individual’s survival. For example, extravagant and colorful tail feathers are likely to attract predators as well as interested members of the opposite sex.

Examples

**Natural Selection **

Camouflage in animals (e.g., peppered moths adapting to industrial pollution).

Beak shape in finches (Darwin’s finches) based on food availability.

Antibiotic resistance in bacteria due to natural selection against antibiotics.

**Sexual Selection **

Peacock Tails: Male peacocks have elaborate, colorful tails. These tails are energetically costly and hinder escape from predators. However, they persist because peahens (female peafowls) find them attractive, leading to more mating opportunities.

Elk Antlers: Male elk grow large antlers, which they use in combat during the mating season. The size and quality of antlers influence female choice.

Bird Songs: Male birds sing complex songs to attract females. The quality of the song reflects the male’s health and genetic fitness.