Sydney: A new study has revealed that a mother’s previous sex partners can influence the appearance of her future child.
The theory that the looks of children may be influenced by past sexual partners dates back to ancient Greece, where it was an accepted fact, but the origin of the genetics in the 20th century disregarded the idea until now.
Scientists at the University of New South Wales have discovered a new form of non-genetic inheritance and have shown for the first time that physical traits of previous sexual mates can be passed on to future children.
According to the researchers, the effect is because molecules in the seminal fluid of the first male mate are absorbed by the immature eggs of the female which then influences the development of the second male’s offspring.
“Our discovery complicates our entire view of how variation is transmitted across generations. It also opens up exciting new possibilities and avenues of research,” said lead study author Angela Crean.
To reach this conclusion, Crean and colleagues Anna Kopps and professor Russell Bonduriansky manipulated the size of male flies and then studied their offspring.
They found that size of the young was determined by the size of the first male their mothers had mated with and not the second male who was their biological father.
“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,” explained Crean.
It shows that various non-genetic inheritance mechanisms make it possible for maternal or paternal environmental factors to influence characteristics of a child, researchers noted.
The study, which has been published in the journal Ecology Letters, has raised many questions about the transmission of certain traits.