Over generations, female reindeer in a Finnish population give birth to larger offspring. Which type of selection is occurring, and how would a distribution curve for this trait change over time?

Question

1. directional selection; the curve would shift to the right
2. stabilizing selection; the curve would become taller in the middle
3. stabilizing selection; the curve would become shorter in the middle
4. directional selection; the curve would shift to the left

Answer 1

The scenario describes a situation where female reindeer are giving birth to larger offspring over generations. This indicates that larger offspring are being favored, which is characteristic of directional selection. In directional selection, the distribution curve for a trait shifts in one direction as a particular phenotype becomes more common in the population.

Since the offspring are getting larger, the distribution curve would shift to the right (indicating larger sizes are becoming more prevalent).

Thus, the correct answer is: 1. directional selection; the curve would shift to the right.