Who are I? Who am we?

These enigmatic questions, borrowed from my colleague and friend Fabrice Vavre, run through most of my work.

  • Who are I? What multitude of genes, cells, symbiotic partners, compose biological "individuals"? And to what extent do these different degrees of organization also constitute individuals, i.e., effective targets of natural selection, carrying adaptations of their own, potentially deleterious at other scales?
  • Who am we? To what extent should the collective, from the ant colony to the ecosystem, also be perceived as an incipient individual ?

As opportunities of collaborations arose, these questionings gave rise to various research projects that are briefly described below. Symbiotic relationships, approached in particular through evolutionary genomics in arthropods, occupy a prominent place, alongside modeling, didactics, and more recently, epistemology.

To discuss these topics, or to learn about possible opportunities to join us, please feel free to contact me.



We seek to test the hypothesis that parasitoids, particularly via domesticated viruses, would constitute preponderant vectors of horizontal transfers.

Of all symbiotic lineages of bacteria, Wolbachia is probably both the most abundant and the most diverse in terms of evolutionary implications. Its vertical maternal transmission has led it to evolve very particular invasion strategies, often beneficial to females (and more precisely, to the cytoplasmic lineage, transmitted by females) and on the contrary deleterious to males.

Wolbachia has always been central to our work, especially concerning its epidemiological dynamics and evolutionary consequences, at the scale of arthropod communities, and the genetic architecture of cytoplasmic incompatibility.

As powerful as DNA variations may be in explaining evolution, what might be the contribution of other modes of inheritance to adaptive evolution ?

The teaching of evolutionary biology is reputed to be difficult. Beyond ideological reasons, this reveals how hard (but important) it is to deal with uncertainty in science teaching, and science in general.

If, in an evolutionary perspective, the individual is recursively conceived as resulting from the merging of individuals of lower scale, how did the smallest scale, the first, come to be?

What were the first units of selection, the first sparks of life? How to define and describe their properties, which necessarily implies combining biological and physico-chemical concepts? Where does individuality begin, and with it evolution by natural selection? In the uncertain hypothesis that such units of selection could exist outside the living world, in other physico-chemical systems, how to recognize them ?

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