This site is here for only one purpose. It is to explain the reasoning behind the above statement. It struck me one day that if people became immortal, it would lead to huge overpopulation, and I quickly realized that I was not unique in this thought. But then it also struck me: women go through menopause. Their eggs die off during their lives, the last of them disappearing when a woman is between 48 and 52 years old. This happens even before women reach puberty, meaning that even eternally young women would go through menopause at about the same age as normal women, or possibly a little later. However, this would still give immortal women a relatively small window of fertility, much as modern women have. If the Grandmother Hypothesis is correct, then it would take thousands of years for womens ferility periods to grow longer, as it would only happen through sexual selection processes. This means that if a cure for death or aging is ever found, something which is everyday coming closer to being a scientific reality, we won't have to worry about the new generation of immortal (or much longer-lived) men and women greatly increasing our current birthrates over their lifespans. Granted, there will be more people alive for much longer, but they won't be reproducing any faster or more often than otherwise healthy humans.
"Overpopulation and Immortality" By Boris Smelov, 06-26-07