Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris1 Can we extend intraspecific population genetics to community population genetics ? Michel Veuille Ecole Pratique des Hautes Etudes Unité de recherche 5202 CNRS-MNHN Paris

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris2 We will admit that: (1)research on COI as an evolutionary genetics system has been investigated intensively for the last 25 years. We know its properties as a population marker, (2)650 bp of COI sequence (a single sequencing run) convey very little information, though enough information to resolve 95% of species identification, (3)It conveys even less information on intraspecific female variation, but can be used in ~ 25% species, (4)The sample size may be small in highly variable species (5)We are not interested in the barcode but in whatever information that is relevant to population biology.

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris3 Over the last 30 years, our view population stablity changed The repertoire of population biology models, relies on equilibrium or steady state conditions. After Wilson and Bosset 1971 Empiricists usually try to falsify these models to understand the history of species e.g. Species/area distribution Colonization-extinction model Hubell’s neutral model Island model Yule’s model Coalescent model

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris4 However, many changes in the history and distribution of populations are due to strong external factors, acting on groups of species (communities) We know that the last big climatic change occured only ~ 10 4 years ago, with consequences on: - species range in boreal areas - forests and arid zones distribution in tropical areas - sea level and shoreline patterns

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris5 For instance, Hewitt (2000) was able to synthesize the distribution pattern of twelve European species into three routes of northward extension.

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris6 Species B Species A If the availability of different kinds of environment change over time, then variation patterns will change accordingly

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris7 Species B Species A If the availability of different kinds of environment change over time, then variation patterns will change accordingly Our ability to explore remote events also changed over the last 30 years

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris8 Present 120 m - 18 ky After Fauvelot et al An example from the literature : mtDNA haplotypes in coral reef fishes

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris9 Proposal: study population differentiation simultaneously in several species From the barcode library, choose some indicator species to explore the history of ecosystems It might be appropriate to adjust the sample size in these species

Banbury october 2007 Michel Veuille Ecole Pratique des Hautes Etudes - Paris10 Resolution power of methods : how much effort should we put in every species ? A cautionary tale: timing of Drosophila melanogaster expansion from Africa to Europe 1995 Bénassi and Veuille (restriction polymorphism in n = 200) Population divergence years ago 2004 Baudry, Viginier and Veuille (sequence polymorphism in 4 genes in n = 153) Bottleneck years ago 2005 Ometto Glinka De Lorenzo Stephan (sequence polymorphism in 260 genes in n = 24) Expansion years ago in eastern Africa followed by a bottleneck years ago in Europe