Seminario INGEBI

Lunes 24 de Septiembre, 13:20 hs.

Dr. Diego Hojsgaard

Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen

Asexual plants: genetic and ecological basis for diversification

Sex is ubiquitous to most eukaryotes. Despite its two-fold reproductive advantage, asexual lineages are scarce among multicellular taxa. The absence of meiotic recombination is expected to hinder the creation of genotypic variation and adaptation to novel conditions (Red Queen hypothesis), and to accelerate the stochastic accumulation of slightly deleterious mutation and genetic degeneration (Muller´s ratchet) leading to genomic decay and extinction of asexual lineages after a brief existence. Even with these predictions of affected adaptability and early demise, the known asexual lineages in vertebrates and plants for which age estimates exist had persisted much longer than what was expected from mathematical models, and are associated to significant increases in biodiversity. Based on new evidence, I´ll present and discuss new hypotheses that explain such disparity and suggest a change in the paradigm that asexuality is an evolutionary dead end.