The average human female outlives the average human male by at least 4 years. What started this line of thought was in the Tribune on 9/17/2012. I cut out the article because it fascinated me that there was proof that another species has females living longer than males, even after the childbearing years have passed. Until I read this article, I had believed only human females survived well past their reproductive years. I was surprised to find out that killer whale mothers survive past their reproductive years. Of course the article explains the probable reason for that; these older female killer whales live longer to ensure that their genetic line through the males will survive.
For decades scientists of all disciplines and especially biologists have tried to understand why human females survive so long. They have studied Catholic nuns to see if such survival rates had something to do with childbearing. The studies found that given similar circumstances, nuns and women who have children live equally long and equally longer than men. There is a caveat to this. The act of childbearing is dangerous in itself and even with modern medicine, more women will die from childbirth than will die from side effects of birth control. The point is that with the exception of childbirth, women live longer than men.
None of the female great apes (chimpanzees, gorillas, and orangutans) survive much past their reproductive years. They keep on having babies in the old age and often they die in childbirth simply because they live so long. But after human females stop reproducing they continue to live productive lives.
But there must be a survival reason for the species for human females to survive so long after no longer reproducing. With modern medical care a human male can also live almost to their 100th birthday. However, the males, unlike human females,
never give up their ability to reproduce. Of course, their reproductive capabilities aren’t of the sort that need a great deal of energy – besides, with Viagra®, et al, they don’t need to do very much to make sure their sperm are headed in the right direction. However, human females then have to expend the energy to carry the infant to term, give birth and be around to raise it until the child can survive on its own.
The only thing I’ve come across is that biologists figure that once humans acquired the ability to speak, it was important that someone live long enough to store and be able to repeat memories that would be beyond the probable memories of the tribe or group they are in. Here’s what I mean: evolution has been going on for millions of years. The time in which reading, writing and civilization has involved human progress is equal to the head on a pin in relationship to a 10 mile long line. In other words, human society AS WE KNOW IT with all the technology, etc. is a blip in time in comparison to the rest of humans’ time on earth. Until the last few thousand years, we were hunter/gatherers not builders and technologists. We survived by being ‘generalists’. We could tackle a multitude of environments and conditions unlike the ‘Dodo’ flightless bird of Australia. The Dodo filled a very specific niche in its specialized environment and when that disappeared, the bird went extinct. In various extreme natural environments where we had to survive against great odds, every little bit of evolutionary help we got – we used. Now we dominate the earth
I believe pretty much what the biologists think – that for some reason once humans had gained the ability to speak there was a need for females to live longer than males SO THEY COULD HELP THE SPECIES SURVIVE! I think, and again this is only my opinion, that the female brain is the reason. Scientists have finally been able to definitively prove that human brains in the male and female are literally hard-wired differently. MRIs and CAT scans have proven that, in general, men tend to do well in math and women tend to do well in language and social sciences. Mind you, this doesn’t mean that some females can’t learn high level math or science, it simply means that there’s a majority of females who take very easily to language, etc. Women and men in the human species may be hard-wired differently but both genders are generalists so you can find men who enjoy cooking and women who enjoy civil engineering.
This plays well in the extra length of life that women have because the survival of the species is so important. Once humanoids began to speak there was a benefit to maintain some link to the past. A link that women had an interest in and that men tended to ignore – survival of younger ones in the tribe or group. The women could pass on knowledge they had gained throughout life and women who went through menopause would no longer be in danger of dying during childbirth. At a time when life spans were around 35 years old, a person who could live another 10 or 20 years would become very valuable to the species by being able to share their knowledge verbally.
“Oh yes, when I was a child and my brother got sick to his stomach my mother gave him a drink of this plant and it made him better.” “Here is what you do when a leg is broken so you can walk again.” “When a baby doesn’t want to be born a woman can reach inside the mother to turn the baby the right way and then it will be born healthy.”
One of the best explanations I've found is: http://www.scientificamerican.com/article.cfm?id=why-is-life-expectancy-lo
But for all this it has only been in the last couple of weeks that I think I’ve found an explanation of why human males have survival problems from the time of their conception. It really does boil down to the: Survival of the Species
Filed under: Anthropology