Monday 24 June 2013

Did men's yearning for young women create the menopause?

My take: this idea reverses cause & effect.

To understand, it is necessary to remember that natural selection favours characteristics that produce the largest number of descendants.  For a woman, there comes a time as she ages, that as her strength & general health decline, her descendants are better served by assisting her children in raising her grandchildren rather than undertaking the risks of pregnancy with her diminished powers.  It is in her reproductive interest, therefor that a woman's fertility declines relatively quickly as she ages.  This terminates in menopause.

Having children does not pose the same risks to men, & so their fertility declines more slowly, in line with the general deterioration of their powers.  In practice, this means that men are capable of fathering children into their 70s & beyond.

Following the natural selection principle, is there a reproductive advantage for men preferring young women?

As discussed above, women's fertility declines as they age.  Youth, therefore, is an indicator of fertility.  In general, characteristics which are thought to be beautiful in women are indicators of fertility, e.g. smooth skin, large breasts.  In general, these indicators of fertility are most prominent in the young.  

To summarize: men are attracted to fertile women, rather than young women per se.

Playing devils advocate, it could be said that the above is mere speculation. Where is the evidence?

Relevant evidence was posted on these pages last week: a study of tips received by lap dancers revealed that men have a preference for women who are ovulating, i.e. whose fertility is greatest.

http://www.dailymail.co.uk/health/article-2341407/Did-mans-yearning-young-women-create-menopause-Research-suggests-men-caused-middle-age-loss-fertility.html#ixzz2WBrkynus / Research wandering eyes middle-age loss of fertility in women study suggests preferential dating menopause women ability offspring children age Professor Rama Singh McMaster University Canada menopausal menopause evolution older women need ability baby child babies children men stop mate sex men's predilection younger females preferential mating menopause scientist researching prolong women women's fertility generation generations preference younger mates reproduce until they died favor favored favoured young mates shunned older males developed losing fertility lost their appeal potential breeding partners average age for the loss fertility 52 chimpanzees closest animal relatives cousins fertile near end their lives age 45 other species pilot killer whales experience published in the journal Public Library of Science Computational Biology controversial theory attracted criticism other specialists  reason infertile middle age mystery Dr Maxwell Burton-Chellew evolutionary biologist Oxford University dismiss dismissed plain wrong human humans strong preference younger females less fertile /

Ditch batteries forever with the NX-ECO Battery-Free Wireless Notebook Mouse by Genius


Credit: Genius/ The Gadgeteer

"Battery free"?  Well, kinda ... it uses a capacitor to achieve the same thing.

So, what's the point?  It charges in 3 minutes (sic).   Fast charge times are typical of capacitors.

Other  characteristics of capacitors are multiple charge cycles (100,000 typical) :) & low energy density compared to lithium ion :(

Frequent recharges are likely to be required, making this a perfect candidate for wireless charging.  Unfortunately the design doesn't provide for it.

http://the-gadgeteer.com/2013/06/23/ditch-batteries-forever-with-the-nx-eco-battery-free-wireless-notebook-mouse-by-genius/ / mouse pointing device electricity computer mouse /