Which of the following is an example of sexual selection? A Koalas with resistance to disease surviving to reproduce - Scottish Highers Biology - Question 17 - 2018

To identify the example of sexual selection, we need to understand what sexual selection is. Sexual selection is a mode of natural selection in which of the individual's ability to obtain or successfully copulate with a mate is a significant factor in reproductive success.

• Option A discusses koalas surviving due to disease resistance, which relates to natural selection rather than sexual selection.
• Option B focuses on camouflage and predation, also a matter of survival.
• Option C is about plant breeding for grain yield, which does not pertain to animal reproduction.
• Option D, however, pertains to female black grouse choosing mates based on display, which is a clear example of sexual selection.

Thus, the correct answer is D: Female black grouse mating with the male with the best display.