Chief Science Correspondent
A study published in Ecology Letters in September suggests that a female's previous sexual partners can influence the phenotypic traits of her subsequent offspring.
Feel free to read that sentence again. The phenomenon is known as telegony, and it may be quite a lot to absorb at once.
Telegony is a bit like epigenetics in that it is a concept that was once widely believed to be true (It was first proposed by Aristotle), but was later largely dismissed by the scientic community.
Of course, this process has not been demonstrated in humans - but the results carry implications that are certainly interesting for our understanding of basic human inheritance.
“There is no evidence of such effects in humans," said lead researcher Angela Crean. "But there has not been any research on this possibility in humans. There is a potential for such effects in mammals."
Scientists have proposed a variety of biological mechanisms that could potentially explain telegony. A 2013 study demonstrated that fetal DNA can pass into the mother during pregnancy, meaning that siblings (or half-siblings, for that matter) could directly pass on DNA. Crean said another potential explanation could involve seminal fluid lingering from a past sexual encounter.
The most logical step would most likely be to attempt to match these phenotypics to genotypes. Could scientists find that a past sexual partner contributes an actual allele, leading to a genotype that would otherwise be impossible? With a smaller model with a series of carefully controlled traits (such as the fly experiment) this test certainly seems a possible next step.
Apart from the obvious implications for paternity questioning in humans, telegony could potentially impact dog breeding, because these animals are controlled closely in an effort to keep their lines pure and produce the offspring with the most desirable traits.
Purebred/mutt mating is a quite controversial topic in the dog breeding community. It's viewed as something to be avoided due to loss of revenue (a dog can only be bred a certain number of times), potential stress on the female, and the possibility of a mixed litter. However, the general consensus within the breeding community has always been that even if a pure-bred gives birth to a mixed-breed litter, she still has the potential to give birth to subsequent pure-bred puppies.
This may not actually be the case. With stronger data and subsequent studies, telegony could demonstrate that these puppies are not truly pure-bred, and could pass down undesirable (and even hidden) traits further down the line. If this does become the case, will these "tainted" mothers become ineligible for breeding?
The answer could prove to be interesting.