If Longevity is Your Goal...
...then do what I do. Keep on having babies as long as possible.
To the great surprise of a group of Finnish scientists, it has been found that, contrary to their expectations, mothers who have children late in life are demonstrating signs of "physical robustness" and aren't aging as fast biologically as their counterparts who quit at an earlier age.
"This result is unexpected because late age at reproduction is not generally believed to be favoured by natural selection, owing to its adverse effects on both the survival of the mother and the offspring, " they said.
"However, the result fits with earlier studies that showed the later a woman goes through the menopause, the longer she is likely to live. "
Of course, the birth control people want to put this down to women being able to control their fertility and delay it to a time when they are psychologically and financially prepared to raise offspring. However, given the large numbers of women who experience problems with fertility when they delay childbearing, how much credence can be given to this idea? Especially as it flies in the face of the actual study, which looked at a group of people who had no access to modern medical care, birth control, or other modern "advances." The study group experienced "natural mortality" and seemed to show a direct link between the physiology that underlies both general physical health and reproductive abilities. In other words, the more your health declines, the faster an end to your reproductive years. Conversely, if you are physically robust and healthy, you'll be able to produce offspring long after your sickly sisters have quit.
I may look like the human equivalent of a brood mare that has seen a lot of years of service, but hey, I must still be pretty healthy, right?