Pliocene-Pleistocene ecological niche evolution in a Mediterranean Carex group.
Guest lecture by Dr. Pedro Jimenez-Mejias, The New York Botanical Garden.
Species ability to adapt to environmental changes is crucial to understand their past and future response to climate change. The Mediterranean basin has experienced remarkable climatic changes since the Miocene, which have greatly influenced the evolution of the Mediterranean flora. Here we examine the evolutionary history and biogeographic20 patterns of two sedge sister species (Carex, Cyperaceae) restricted in the western Mediterranean basin, but with Pliocene fossil record in central Europe. In particular, we evaluated ecological niche through time and its influence in lineage differentiation. We carried out a dated phylogenetic-phylogeographic study based on seven DNA regions (nDNA and ptDNA) and fingerprinting data (AFLPs). Comparisons of ecological niche and species distributions were modelled for the Pliocene, Pleistocene, and present. Phylogenetic and divergence time analyses revealed that both species form a monophyletic lineage originated in the late Pliocene-early Pleistocene. Clear genetic differentiation was detected between them with genetic clusters following disjunct areas, indicating the predominant role of geographic barriers limiting gene flow. A remarkable shift in the climatic requirements between Pliocene and extant populations was detected, although the niche seems to have been relatively conserved since the Pleistocene split of both species.
About the speaker
Dr. Pedro Jimenez-Mejias has a wide interest in different aspects of plant diversity, but a particular interest on all aspects of the genus Carex (Cyperaceae). His research spans from paleobotany, morphology, taxonomy, population genetics, phylogenetics, diversification and reproductive biology. His article on “Megaphylogenetic specimen-level approaches to the Carex Phylogeny" was an important contribution to a deeper understanding of on eof the world’s most species rich genera.