Ecological en evolutionary determinants of diversification: integrating biogeography, functional ecology, and macroevolution – ECOEVOBIO

The project has 1) a theoretical part that aims to improve phylogenetic inference methods; this part relies on birth-death and branching processes 2) a data componant aimed at compiling large datasets 3) an application of the newly developed phylogenetic inference methods to data in order to improve our understanding of the processus generating wide variations in species richness across the geographical space and the tree of life.

Mathematical models that allow reconstructing past biodiversity often contradict fossil data gathered by paleontologists in the field. These models have a hard time identifying periods of extinction and biodiversity loss. Our results explain and correct these inconsistencies. We show that inconsistencies appear if the model considers a species group as a whole, ignoring the heterogeneity of diversification rates across phylogenetic branches. In this case, the branches that that diversified recently and rapidly mask extinctions in the global phylogeny. We correct this issue with a mathematical model that allows taking into account periods of diversity decline and the heterogeneity of diversification rates across species groups. For cetaceans, we obtain diversity curves in agreement with fossil data. In particular, our results suggest that most extant cetaceans arose
from four recent radiations, with a few additional species arising
from clades that have been in decline over the last ~10 Myr. Our model, implemented in R, is publicly available and is used by the international scientific community.
The project also allowed obtaining theoretical results on protracted speciation, on individual-based diversification models, to produce a Review piece (invited, Ecology Letters) on phylogenetic approaches to diversification, and a Perspective piece (invited, Ecology Letters) on applications of phylogenetic approaches to global change research. On the empirical standpoint, besides cetaceans, we worked on the diversification of microorganisms, mammals, and flowering plants.

The models developed are going to be applied on a wide range of empirical phylogenies in order to identify general tendencies.

Paper resulting from an international working group
Dornelas, M., Buckland, S., Chazdon, R., Chao, A., Colwell, R., Curtis, T., Gotelli, N., Kosnik, M., McGill, B., Magurran, A., Morlon, H., Mumby, P., Øvreås, L., Studeny, A. and Vellend, M. (in press) Quantifying temporal change in biodiversity: challenges and opportunities Proceedings of the Royal Society B

Applications of the methods developed to microorganisms
Morlon, H. (2012) Microbial cooperative warfare Science 334: 1184-1185

Morlon, H., Kemps, B., Plotkin, J.B. and Brisson, D. (2012) Explosive radiation of a bacterial species group Evolution 66: 2577–2586

Applications of the methods developed to conservation
Rolland, J., Cadotte, M., Davies, J., Devictor, V., Lavergne, S., Mouquet, N., Pavoine, S., Rodrigues, A., Thuiller, W., Turcati, L., Winter, M., Zupan, L., Jabot F., and Morlon, H. (2011) Using phylogenies in conservation: new perspectives Biology Letters

Methodological developments (explained in «Results«)
Morlon, H., Parsons, T.L. and Plotkin, J.B. (2011) Reconciling molecular phylogenies with the fossil record Proceedings of the National Academy of Sciences 108: 16327-16332

Paper resulting from an international working group
McInnes, L., Baker, W.J., Barraclough, T.G., Dasmahapata, K.K., Goswami, A., Harmon, L.J., Morlon, H., Purvis, A., Rosindell, J., Thomas, G.H., Turvey, S.T., Phillimore, A.B. (2011) Integrating ecology into macroevolutionary research Biology Letters

The systematic variation in species richness across taxonomic groups and geographic regions is one of the most striking patterns on the planet. Yet, the processes driving this variation are poorly understood. Our project aims at identifying specific ecological variables, including species’ association with the tropical or the temperate biome, that influence rates of molecular evolution and/or diversification, and ultimately species richness. We propose to develop the theoretical tools, and to compile the empirical data, necessary to analyze the patterns and process of diversification dynamics using phylogenies of extant taxa. We will model the dynamics of diversification in a non-spatial and spatial context, using individual-based and lineage-based models. We will compile a large database for flowering plants, mammals, and birds at continental/global spatial scales. This data will encompass species’ phylogeny, geographic location, a suite of ecological traits characterizing them, and fossil record when available. Applying the theory to this ambitious database, we will identify key ecological factors influencing the tempo and mode of diversification across lineages and geographic regions.