Sexual Selection

Question 1

What is intersexual selection?

Answer 1

• one sex chooses
• females choose mates based on displays and physical traits
• males compete to gain the attention of females through elaborate courtship displays, calls and ornamentation

Question 2

What is intrasexual selection?

Answer 2

• individuals of one sex compete amongst themselves
• males monopolize access to females through outcompeting rituals, control of females or control of a resource that is important to females

Question 3

What are some of the methods for intrasexual selection?

Answer 3

• sperm competition
• mating plugs
• scrapers
• sneakers and cheaters

Question 4

What are mating plugs?

Answer 4

after mating, leave a plug to prevent other males from mating

Question 5

What are scrapers?

Answer 5

scrape out sperm deposited by other males

Question 6

What is colonel interference?

Answer 6

they are adaptive mutations that emerge in different background cannot be combined in asexual populations

Question 7

What is the Muller’s ratchet?

Answer 7

by chance, part of the population carrying the fewest deleterious mutations. Sex can break the ratchet through recombination and independent assortment

Question 8

What is sexual dimorphism?

Answer 8

a distance difference in size or appearance beyond the difference in their sexual organs

Question 9

What is a reason organisms exchange genetic material?

Answer 9

• breaking up successful combinations of genes in exchange for potentially flawed combinations in your offspring

Question 10

What are 3 of the costs of sex?

Answer 10

1. competition for mates (sexual selection)
2. exposure to predation by attracting mates
3. sexually transmitted disease