Why are males and females always (almost) equal in number?

Of course, a 50/50 sex-ratio is not always the case among animal species, but frequently it is, and the evolutionary logic is as follows: Consider a sexually-reproducing species that is 90% female and 10% male. In the current generation, 90% of the genes are from the females, and 10% are from the males. read more

Males and females are not always equal in number. It has only a chance factor . Since there are X & Y sperms approaching to fertilise an egg its a 50: 50 game.But we are not sure whether its X or Y each time .It may happen that an X only fertilise for a number of times and not the Y . read more

It might seems like you could get away with having just a few males and many females, but natural selection will not allow this. If you have a large number of females with only a few males, then there would be nothing to stop a gene for making sons from running wild and producing many sons, until the pendulum has swung into a stable 50/50 ratio. read more