From these slim clues, Hawkes and her colleagues developed the "grandmother hypothesis," which holds that women past childbearing age helped not just their children, but their children's children, and lengthened the human lifespan in the process. Without babies of their own to lug around, grandmothers had both time and a very good reason to be useful. When they eked out food for their daughters' children, they reduced the chance that those children would die. That gave the grandmothers a better chance of passing on their own predisposition to longevity. (In general, grandmothers appear to have helped daughters' offspring more than sons'; evolutionary theorists explain this by pointing out that a daughter's maternity affords a surer genetic connection than a son's paternity, unless you all but imprison your daughter-in-law.2)I've written about the Grandmother Hypothesis before [The Adaptive Value of Menopause] [How Women Got Their Menopause ]. It's an adaptationist just-so story that makes no sense whatsoever as soon as you start thinking critically.
But that's not what worries me today. What troubles me is that grandfathers don't seem to figure into these stories. Why is that? Are we completely irrelevant to our children and grandchildren?
8 comments :
Larry, I'm sure that you will be every bit as evolutionarily important to Zoe as Mrs. Sandwalk ... for what that's worth.
More importantly, I'm sure that Zoe will be better off over all because of both of you, even if it never shows up in her or her descendants' genes.
This is an easy one:
There were no living grandfathers in earlier times because all grandfathers were killed by saber-toothed tigers during hunting. You know, young men run faster. Sacrificing themselves allowed women to evolve the gransmother role. Extiction of the cat after the last ice age helped grandfathers to survive. However, due to a lack of selective forces grandfathers never evolved any senseful function and are stuck in a evolutionary dead end street.
This all actually shows a creationist good point.
Anyone can speculate about selection doing this or that.
Often the only difference is if there are degrees on the wall.
Lots of evolutionary concepts I find just as well say selection did this or that.
Anythings possible.
If selection can turn primitive stuff into complicated creatures then why not minor social things?
Selection never brought change to human populations because the great point is that populations growing so quickly with good food sources and enough peace quickly overwhelm any possible selectionism going on.
Big populations are not affected by selection and these are the populations that made the world. not tiny tribes.
The bible says man is given 70 years and 80 with health.
Thats why the elderly are around.
Its just for time enough to figure out about eternity.
Sounds almost as reasonable as the grandmother hypothesis. :-)
However, I can think of one small problem. If all of the grandfathers were dead then why did their spouses need to evolve menopause in order to stop having babies? Was there a lot of hanky-panky going on in those hunter-gatherer societies?
This all actually shows a creationist good point.
Of course it does. :-)
That's because the only "good points" that creationists have are gaps in our understanding of evolution. Think of evolution as a giant jigsaw puzzle that's almost complete. The big picture is perfectly clear. The one or two missing pieces (e.g. menopause) are the only things creationists can point to in support of their side.
They then proceed to extrapolate from this missing piece to the outlandish claim that the big picture is something entirely different than it seems. They do this because they are completely ignorant of the entire rest of the puzzle. It's as though they've never seen the forest because they are only looking at trees.
That's exactly what you do in the rest of your comment.
Have you no shame?
The bible says man is given 70 years and 80 with health.
Except for those that lived to the ripe old age of 900 or so.
Do you even read your big book of bad ideas, or do you get all of your ideas spoon fed to you ?
@Larry
You tell us to think of evolution as a nearly complete jigsaw - but given your definition of evolution as mere change in allele frequency over generations, or some such nonsense, that makes no sense. It's almost as if you have about 15 different definitions of evolution to hand and flit between them depending on what particular unscientific points you wish to make at any given time.
Steve Oberski,
The "big book of bad ideas" is a great title for the Bible and other religious texts. Thank you. A++++
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