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In a population that grows, would a disparity in having a boy/girl probability cause the ratio of males to females tend to the same? e.g. if the probability of having boys was .49 and having a girl was .51 would that mean a growing population would tend to be 49% male and 51% female?

What about a non growing population?, would that mean finally one gender will be the only gender left after sufficient amount of time?

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up vote 5 down vote accepted

It's not possible for one gender to "go extinct", as it were. That would happen if there were two different species whose rates of reproduction were different; that is, if girls produced only girls and boys produced only boys.

Here, in each generation you expect 49% boys and 51% girls to be born. No matter what the initial population, once the first generation has died you will be left with an expected proportion of 49% males to 51% females. This holds whether or not the population is growing or fixed -- but only assuming the death rates for males and females are the same.

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