Timing the origin and past connections between Andean and Atlantic Seasonally Dry Tropical Forests i

Rafael Felipe de Almeida (1,2*), André Marcio Araújo Amorim (1,3) & Cássio van den Berg (1)

(1) Universidade Estadual de Feira de Santana, Departamento de Ciências Biológicas, Programa de Pós-Graduação em Botânica, Av. Transnordestina s/n, 44036-900, Feira de Santana, Bahia, Brazil

(2) Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Botânica, Avenida Antonio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, Minas Gerais, Brazil

(3) Universidade Estadual de Santa Cruz, Departamento de Ciências Biológicas, Rodovia Ilhéus-Itabuna, Km 16, 45600-970, Ilhéus, Bahia, Brazil

Author for correspondence: dealmeida.rafaelfelipe@gmail.com

We investigated the timing of origin and past connections between Andean and Atlantic Seasonally Dry Tropical Forests in South America based on the biogeographical history of Amorimia, a genus of Malpighiaceae restricted to South America. We used a time-calibrated phylogenetic tree based three cpDNA (ndhF, rpl16, and trnQ-rps16) and two nrDNA (ETS, and ITS) regions including all currently accepted species in Amorimia for ancestral area reconstructions. Our results show that: (1) the ancestor of Amorimia originated in Atlantic dry forests around 22.0 Mya; (2) ancestors of both Amorimia subgenera arose in Southern Brazilian dry forests from 18.0 to 14.0 Mya; (3) the remaining lineages in the genera diversified from Mid-Miocene to the late-Pliocene; and (4) a history of two expansion events during early and middle Miocene, besides several colonization events in different nuclei of dry forests in South America is suggested.

Keywords: ancestral area reconstruction; biogeography; Malpighiales; molecular clock; phylogeny