A)
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.
(8 points)
Part A:
- Sexual selection: This type of selection occurs when certain traits increase an individual's reproductive success, often in the context of mate choice. It can lead to the evolution of traits that are not necessarily beneficial for survival, but are advantageous in terms of reproduction.
- Artificial selection: This is the process by which humans intentionally select and breed individuals with desirable traits. It is commonly used in agriculture and animal breeding to produce organisms with specific characteristics.
- Natural selection: This is the process by which organisms best adapted to their environment survive and pass on their genes to the next generation. It is the driving force behind evolution and is responsible for the adaptation of populations to their ecological niches.
Part B:
- Example of a trait favored in sexual selection: Peacock's extravagant tail feathers. These can be favored by sexual selection as they are attractive to females and increase the peacock's mating success. However, they may be selected against in terms of natural selection as they can make the peacock more vulnerable to predators due to their visibility.
- Example of a trait favored in artificial selection: High milk production in dairy cows. This trait is favored by artificial selection as it increases the economic value of the cows for milk production. However, it may be selected against in terms of natural selection if it comes at the cost of other physiological functions or survival traits.
- Example of a trait favored in natural selection: Camouflage in prey animals. This trait is favored by natural selection as it helps the prey to evade predators and survive in their environment. However, it may be selected against in terms of sexual selection if it makes the animal less visually attractive to potential mates.