does that mean therefore that there are NOT 3 billion females and 3 billion males in the world, since, if it is not just about the sperm race and our bodies have mechanisms to determine the chances of survival of the foetus, then it is no longer 50/50?
World-wide there are 107 men born for every 100 women. As women tend to get older the overall difference is 101/100. It also differs per country, and possibly other groupings.
The sperm race isn't 50/50 either. The y-sperm is slightly lighter than the x-sperm and thus slightly faster. On the other hand, women tend to live longer.
