"Beyond genes": what if we rethought the notion of heredity?

Until the end of the 20th century, heredity was seen by scientists as a matter of genes and DNA transmission. But in recent decades, research has revealed non-genetic transmissions, helping to explain why children on average resemble their parents more than other individuals in a population. These include epigenetic (changes in gene activity without changing the DNA sequence), microbial, hormonal and behavioral transmissions. Some biologists and philosophers now speak of "extended heredity".

"The challenge is to redraw the concept of heredity, going beyond the strictly genetic vision that has prevailed until now", explains Gaëlle Pontarotti. "The aim of my book and my research is to articulate different forms of transmission and to rethink the compatibility between heredity and transgenerational freedom."

For since Greek antiquity, everything suggests that we are locked into a family destiny. But if heredity goes beyond genes, what room for manoeuvre do we have? "The challenge is to find a happy medium between hereditary fatalism and the illusion of omnipotence in the face of our heritage", sums up the researcher.

This new concept overturns our vision of filiation and the status of the individual. We are no longer simply objects determined by causes beyond our control: we are once again actors in what we receive and transmit. It also invites us to reconsider the place of genes in filiation: is the parent fundamentally the one who transmits his or her genetic heritage?

And what if, ultimately, our heritage was also what we chose to make of it?

Cover credit: Éditions Gallimard, book visual Par-delà les gènes.