Some male peacocks used to have bright and large tails while others had dull, smaller tails.

Female peacocks will only mate with the ones that have the brightest and largest tails. Explain how this would impact the offspring of male peacocks over time.

Over time, the offspring of male peacocks with bright and large tails would become increasingly more common in the population. This is because female peacocks will only mate with males that have the brightest and largest tails, meaning that the genes for bright and large tails will be passed on to the offspring more often than the genes for dull and small tails. As a result, the population of peacocks will become increasingly more likely to have bright and large tails.