biology help!?

Question

Why do you suppose there are usually equivalent numbers of males and females in most species?

Why would natural selection favor an even number of males and females? Why is this evidence that natural selection acts on individuals rather than populations?

Answer 1

There are usually more females than males...mainly because males can impregnate many females in a short time as opposed to a female that would have to wait to give birth each time. Colonial insect colonies are usually made up of only females. A pride of lions contains many females and one or two dominant males. Females are the majority in most cases. Natural selection would probably favor more females than males because it increases the chances of producing more offspring...unless the animals were monogamous. Natural selection acts upon a population of animals...animals that are more fit survive and you see a curve in the population as a whole. Your questioning is a little off...backwards, I would say.

Answer 2

if there were more males than females, or vice versa, there wouldn't be a maximum reproduction rate.

For example, if there was 99 males and one female, you can only have one baby, maximum. whereas 50 males and 50 females, there would be 50 babies.

natural selection is all about surviving, so naturally, the more babies, the more survival.

about the third question, overtime, natural selection do affect populations. Eventually, slow animals who can't defend themselves are wiped out, and fast animals who can, will live.