Michel Veuille Ecole Pratique des Hautes Etudes - Paris 1

Banbury 28-31 october 2007

Can we extend intraspecific population genetics to community population genetics ?

Michel VeuilleEcole Pratique des Hautes Etudes

Unité de recherche 5202 CNRS-MNHNParis

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 2

Banbury 28-31 october 2007

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.

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 3

Banbury 28-31 october 2007

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 distributionColonization-extinction modelHubell’s neutral model

Island modelYule’s model Coalescent model

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 4

Banbury 28-31 october 2007

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 ~ 104 years ago, with consequences on:- species range in boreal areas- forests and arid zones distribution in tropical areas- sea level and shoreline patterns

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 5

Banbury 28-31 october 2007

For instance, Hewitt (2000) was able to synthesize the distribution pattern of twelve European species into three routes of northward extension.

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 6

Banbury 28-31 october 2007

Species BSpecies A

If the availability of different kinds of environment change over time, then variation patterns will change accordingly

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 7

Banbury 28-31 october 2007

Species BSpecies 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

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 8

Banbury 28-31 october 2007

Present

120 m

- 18 ky After Fauvelot et al. 2003

An example from the literature : mtDNA haplotypes in coral reef fishes

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 9

Banbury 28-31 october 2007

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

Michel Veuille Ecole Pratique des Hautes Etudes - Paris 10

Banbury 28-31 october 2007

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 10.000 years ago

• 2004 Baudry, Viginier and Veuille (sequence polymorphism in 4 genes in n = 153)Bottleneck 6.400 years ago

• 2005 Ometto Glinka De Lorenzo Stephan (sequence polymorphism in 260 genes in n = 24)Expansion 60.000 years ago in eastern Africa followed by a bottleneck 16.000 years ago in Europe