Oral Presentation- Symposium 12th International Mammalogical Congress

The influence of ecological and geographical context on a recent rapid radiation: A case of study in the sigmodontine rodents. (#412)

Andrés Parada Rodriguez 1 , Guillermo D'Elía 1
  1. Universidad Austral de Chile, Valdivia, Valdivia, LOS RíOS, Chile

Rodents of the subfamily Sigmodontinae (family Cricetidae), which originated in the Late Miocene, comprise one of the most diverse clades of Neotropical mammals (above 400 living species grouped into ca. 86 genera). Sigmodontine genera have been traditionally assembled into groups, most of which are formally recognised as tribes, which greatly differ in species richness and ecological diversity. As such, the ecological and geographical contexts are crucial to understand sigmodontine diversification. Previous studies failed to solve most relationships among tribes, remaining unknown if this is a case of almost-simultaneous cladogenesis within a rapid radiation or simple lack of sufficient data to resolve this relationships. We aimed to understand the diversification pattern, rates and drivers of this radiation. We discuss the timing of the radiation of the main sigmodontine lineages. We report that the evolution of habitat preference (considering vegetation type and elevational range) was associated with diversification rates. We propose that a overall observed diversification slowdown might be the result of ecological or geographical constraints. Lineages-per-area-through-time plots show that tropical areas accumulated more lineages than other areas. This highlights the influence of tropical lowlands -which might have acted as both a cradle and a museum of species-in the diversification of Neotropical mammals. Financial support: FONDECYT 1141055, FONDECYT-Postdoctorado 3150604.