Séminaire du Lundi 21mars | Gilles Didier| »Estimation des taux de diversification à partir du registre fossile »

Bonjour à tous,

Lundi prochain Gilles Didier est invité par Séverine Bérard pour nous parler de :

« Estimation des taux de diversification à partir du registre fossile »

Gilles Didier
Institut de Mathématiques de Marseille

We are interested in how fast species born and die. Diversification
rates are estimated from phylogenies which contains extant and
(sometimes) fossil taxa. By  nature, rate estimations depend heavily on
the time data provided in phylogenies, which are  divergence times and
(when used) fossil ages. Among these temporal data, fossil ages are by
far the most precisely known (divergence times are inferences calibrated
with fossils). We present an original method to compute the likelihood
of a phylogenetic tree with fossils in which the only known time
information is the fossil ages.
Testing our approach on simulated data shows that the maximum likelihood
rate estimates from the phylogenetic tree shape and the fossil dates are
almost as accurate as the ones obtained by taking into account all the
data, including the divergence times. Moreover they are substantially
more accurate than the estimates obtained only from the exact divergence
times (without taking into account the fossil record). We finally
estimate the diversification and fossilization rates from a
paleontological dataset (eupelycosaurs tree). (joint work with Michel
Laurin, Museum d’Histoire Naturelle de Paris)

Venez nombreux l’écouter lundi à 11h en salle Louis Thaler, bat 22, 2e étage.

A lundi!