What is the relationship between competition for mates and natural selection?

Answer 1

'competition between mates' as the words suggest mean that organisms in a habitat compete for their basic needs including mates. three tigers could be competing for one tigress. and the one that's the fittest wins (survival of the fittest).

when thinking about 'natural selection', think evolution. this is to say, over time, the traits that are strongest in an organism gets passed on from one generation to another. what you get as an end result is you may notice the weaker traits have extinguished while the stronger traits have become more obvious.

now the correlation between the two: imagine having two tigers fighting for a tigress. the stronger one with sharper claws and teeth wins the tigress over. this simply means the weaker tiger probably had some flaws in its traits. and because this winning tiger has strong traits, they get passed on and that's evolution (natural selection).

Answer 2

Answer 1

That is a very good question. I'm sure there have been many research papers on this subject, and many hypotheses are extant on this subject. As a layman, I can offer you my simplistic speculation:

In most animals that reproduce sexually and have sexual dimorphism (difference between male and female form), the female has the task of bearing young. This often means two things:
1. The female is more vulnerable during pregnancy.
2. The female can mate less often than the male, because she needs time to produce the egg or baby.
This could result in a situation wherein the male is more promiscuous than the female. After all, the male is always ready to mate, and needs to invest relatively little effort, while the female is stuck with the result.
As a consequence, given an equal number of males and females, there will always be more males ready to mate than there are females. In such a situation, males may be more likely to compete with one another for available females than the reverse. As a result, the situation male-competion-female-choice could evolve quite easily.

Note that I offer this explanation as merely one possible scenario, and that there may be much wrong with what I said. Also note that the male-competion-female-choice pattern is not the pattern for all sexually reproducing organisms with sexual dimorphisms, although it is very common.

Answer 3

Basic Darwinism. Survival of the fittest. The strongest, wiliest males will make the strongest fittest offspring.