Question

1. Discuss Pleiotropy and Developmental tradeoffs? ( Please give me a clear and broad explanation. This is for Evolutionary Biology)

Answer 1

Pleiotropy: A single mutation produces multiple phenotypes.

This happens if a mutation occurs in a major regulator that is involved in multiple pathways.

For example, an auxin biosynthesis mutant in plants shows multiple phenotypes such as leaf serration, lateral root phenotype, and branching phenotypes. This is because auxin is involved in all these processes.

Developmental tradeoff: A trade-off is a decision that involves losing one quality/quantity so that it can gain an advantage in other characters. A tradeoff occurs when a beneficial change in one quality/trait is linked to a detrimental change in the other trait.

Examples:

i. Sweating in hot conditions cools off the organism. However, the organism may face the risk of dehydration due to water loss.

ii. A large beak in raptor helps in prey capture but it is inefficient in nest-building.