Friday, November 20, 2015

God--He's a Real Smart Guy: Virginity, Telegony and Damaged Goods

The concept of chastity, including that woman should be virgins at marriage, is increasingly mocked in our day and age. (See, e.g., "Virgin bride presents pastor father with 'certificate of purity' on wedding day, sparking outrage: 'This is just sick'"--New York Daily News; and this from the Daily Mail: "'No hymen, no diamond': Male activist Facebook group mocked for demanding that women are virgins before they get married"). It is viewed as a throwback with no real function or reason. However, there is recent evidence that one historic reason--telegony--is valid.

Telegony was a once discredited theory--even termed a superstition--that a woman's sexual partner(s) could pass traits on to subsequent children of the woman, even if the children were sired by a different person. Apparently the science was not settled. An abstract from  Reprod Domest Anim. 2011 Apr;46(2):338-43.
Telegony is the belief that the sire first mated to a female will have an influence upon some of that female's later offspring by another male. Although the reality of telegony was acknowledged by such authorities as Darwin, Spencer, Romanes and many experienced breeders, it has been met with scepticism because of Weismann's unfavourable comments and negative results obtained in several test experiments. In this article, alleged cases of telegony are provided. A search of the literature of cell biology and biochemistry reveals several plausible mechanisms that may form the basis for telegony. These involve the penetration of spermatozoa into the somatic tissues of the female genital tract, the incorporation of the DNA released by spermatozoa into maternal somatic cells, the presence of foetal DNA in maternal blood, as well as sperm RNA-mediated non-Mendelian inheritance of epigenetic changes.
An abstract from Gene. 2013 Jul 25;524(2):414-6:
Telegony is a discredited genetic phenomenon that a previous male may influence the characteristics of offspring subsequently borne by the same female to another male. Although its reality was acknowledged by such authorities as Charles Darwin and Herbert Spencer, it has been met with skepticism because of a lack of understanding of the theoretical basis for telegony. With the discovery of fetal genes in mother's blood, the penetration of somatic cells by sperm, and the ability of RNA to program genome rearrangement, mechanisms might exist for telegony.
An abstract from Ecology Letters on September 30, 2014:
Newly discovered non-genetic mechanisms break the link between genes and inheritance, thereby also raising the possibility that previous mating partners could influence traits in offspring sired by subsequent males that mate with the same female (‘telegony’). In the fly Telostylinus angusticollis, males transmit their environmentally acquired condition via paternal effects on offspring body size. We manipulated male condition, and mated females to two males in high or low condition in a fully crossed design. Although the second male sired a large majority of offspring, offspring body size was influenced by the condition of the first male. This effect was not observed when females were exposed to the first male without mating, implicating semen-mediated effects rather than female differential allocation based on pre-mating assessment of male quality. Our results reveal a novel type of transgenerational effect with potential implications for the evolution of reproductive strategies.
Or, as The Telegraph reports the findings:
The idea that the physical traits of previous sexual partners could be passed on to future children was hypothesised by Aristotle and formed part of the reason that kings were banned from marrying divorcees. 
But the birth of genetics dismissed ‘telegony’ as a superstition which had no basis in science. 
Now, however, an intriguing new study suggests children may resemble a mother’s previous sexual partner after all. 
Scientists at the University of New South Wales discovered that, for fruit flies at least, the size of the young was determined by the size of the first male the mother mated with, rather than the second male that sired the offspring. 
It is the first time that telegony has been proved in the animal kingdom. 
The researchers propose that the effect is due to molecules in the semen of the first mate being absorbed by the female's immature eggs where they influence future offspring.
(See also the International Business Times and the Daily Mail).

And today I came across this article, "A Woman’s Body May Incorporate DNA From The Semen Of Casual Sex Partners," which explains the implications from this most recent study:
Compelling new scientific research has shown that female insects and mammals are able to absorb foreign DNA throughout the cells of their bodies. In human beings, this phenomenon has been conclusively shown to occur in women during pregnancy where genetic material from her growing fetus becomes fused within areas of her brain, affecting her chances of developing Alzheimer’s disease.

The evidence now shows that female animals can incorporate sperm DNA from her prior sex partners. This foreign DNA winds up in future children after the woman successfully reproduces with a completely different male. In the human world, this means that the children a man has with a promiscuous woman could possess genes from previous sexual partners he has never seen or met.

There are existing sociological studies that show a marriage is far more likely to fail when a woman had more than two prior sexual partners
[footnotes omitted], but now renewed support for the once-questionable field of telegony is showing that there are also genetic reasons not to start a family with a promiscuous woman: children you have with her may have their gene pool polluted by her random affairs and one-night stands.

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The above study has two seismic implications. The first is that a woman can absorb enough DNA during her lifetime that it changes her phenotype (i.e. her appearance and overall health state). There could be some truth to the phrase “slut face” in which highly promiscuous women suffer a change to their appearance because of all the variable sperm from different males that have been deposited inside them.

The second implication stems from the fact that it’s scientifically conclusive that single mothers have DNA of their bastard children residing permanently within their bodies. Any man who reproduces with a single mom will have a child that contains DNA from the bastard spawn, which of course includes DNA from the absentee father. This means that men can be genetically cuckolded without being traditionally cuckolded, and that having a baby with a single mom is essentially giving the father of her first child a bonus prize in the game of evolution.

Microchimerism has also been noted in dogs, where older siblings pass on their DNA to younger siblings, suggesting that first-borns possess the highest genetic purity, a suspicion perhaps suspected by the royalty of old. Not only that, but the mother dogs incorporated Y-chromosome material from her male children. The mother dog essentially becomes more masculine by having sons.
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For thousands of years, a woman’s purity was cherished above all else when it came to creating a family. Now the scientific community is confirming the validity of that practice. ....

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