Telegony, which originated with the ancient Greek philosopher Aristotle, is the idea that a male can leave a mark on his mate’s body which influences her offspring with a different male. Telegony was popular as a scientific hypothesis in the 1800s and used as a fear tactic to prevent women from copulating with different races or lower classes. The notion was rejected in the early 1900s as incompatible with the new science of genetics.
Building on recent advances in our understanding of inheritance that offspring‐parent resemblance cannot be explained solely by the transmission of parental genes, a trio of Australian scientists — University of New South Wales scientists Dr. Angela Crean, Professor Russell Bonduriansky and Dr. Anna Kopps — discovered a modern form of telegony in fruit flies, wherein the offspring can resemble their mother’s previous sexual partner.
Their study is published in “Revisiting telegony: offspring inherit an acquired characteristic of their mother’s previous mate,” Ecology Letters, Sept. 30, 2014.
According to the scientists’ press release, they hypothesized that molecules in the seminal fluid of the a male fruit fly can be absorbed by the female’s immature eggs and then influence the growth of her offspring sired by a subsequent male.
The scientists produced two groups of male flies, large and small, by feeding them diets as larvae that were high or low in nutrients. Males that are well-fed as larvae go on to produce big offspring.
The female fruit flies, when immature, were mated with either a large or a small male. Once the females had matured, they were mated again with either a big or a small male, and their offspring were studied.
The scientists found that the size of the young was determined by the size of the first male the mother mated with, rather than the second male who sired the offspring.
Lead author Dr. Crean said:
“We found that even though the second male sired the offspring, offspring size was determined by what the mother’s previous mating partner ate as a maggot. We know that features that run in families are not just influenced by the genes that are passed down from parents to their children. Various non-genetic inheritance mechanisms make it possible for maternal or paternal environmental factors to influence characteristics of a child. Our discovery complicates our entire view of how variation is transmitted across generations….Our new findings take this to a whole new level – showing a male can also transmit some of his acquired features to offspring sired by other males. But we don’t know yet whether this applies to other species.“
Below is the study’s Abstract:
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.
To ascertain that the mechanism by which the offspring’s size is determined, not by its biological father, but by the semen of the mother’s previous sexual partner, Crean repeated the studies with an unfortunate group of male flies who had their genitalia glued down so they could not pass on any semen during their encounters. When these males, both large and small, were the first “mates” for females, their size did not have an effect on the offspring when the female mated with her second mate and had offspring. (Time)
Dana Dovey writes for Medical Daily, October 1, 2014:
To answer the question that I’m sure is on every one of your minds, no the researchers are not yet sure whether this phenomenon exists in any other species, but testimony of many experienced breeders suggests this phenomenon exists in other species. [It’s a long-held belief among animal breeders that pure-bred progeny are best produced by females who have never mated before.] As for humans, I don’t even want to begin opening that can of worms, but Crean did tell Medical Daily in an email that she’s not ruling out this possibility.
“There is no evidence of such effects in humans, but there has not been any research on this possibility in humans. There is a potential for such effects in mammals,” explained Crean. “For example, there is a lot of foetal DNA in maternal blood during pregnancy, and this could potentially play a role in such effects. There is also evidence in mammals that seminal fluid affects offspring development, so semen from one male could potentially influence the development of eggs fertilized by another male (which is what we think is happening in flies).”
Crean added that due to ethical restraints it would be difficult to conduct a similar experiment on humans.
Needless to say, if the telegony discovered in fruit flies is true also for humans, the implications are serious. At a minimum, it should give women pause to reconsider how sexual promiscuity can affect their future children.
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