Consider the roles of different types of selective pressure
Part A: Compare and contrast sexual selection, artificial selection, and natural selection
Part B: Give examples of traits that may be favored in sexual selection, artificial selection, and natural selection. For each, explain if the trait would be favored by one type of selection but selected against by another type of selection.
Part A:
1. Sexual selection: Sexual selection refers to the process where certain traits in individuals are favored because they increase their chances of mating and reproducing. This can occur through competition between members of the same sex (intrasexual selection) or through mate choice (intersexual selection).
2. Artificial selection: Artificial selection is the process where humans intentionally breed individuals with desirable traits to produce offspring with those traits. This often leads to changes in domesticated plants and animals over generations, as humans selectively breed for characteristics that are beneficial to them.
3. Natural selection: Natural selection is the process where certain traits in individuals are favored because they increase their chances of survival and reproduction in a given environment. Individuals with these advantageous traits are more likely to pass on their genes to the next generation, leading to evolutionary changes over time.
Part B:
1. Sexual selection: Examples of traits that may be favored in sexual selection include elaborate ornaments or displays in males (such as peacock feathers) that attract females, as well as size and strength in males for competing with other males. These traits may be favored in sexual selection but selected against in natural selection if they make individuals more vulnerable to predators.
2. Artificial selection: Examples of traits that may be favored in artificial selection include increased milk production in dairy cows, larger fruits in agriculture, and specific coat colors in pets. These traits may not necessarily be advantageous in natural selection, as they may not provide a survival or reproductive advantage in the wild.
3. Natural selection: Examples of traits that may be favored in natural selection include camouflage in prey species to avoid predation, antibiotic resistance in bacteria to survive in a changing environment, and faster running speeds in prey species to escape predators. These traits may not necessarily be favored in sexual selection or artificial selection if they do not directly contribute to mating success or human preferences.