Dados do Trabalho

TÍTULO

MITOCHONDRIAL PHYLOGENOMICS OF NEOTROPICAL TREE SQUIRRELS (SCIURIDAE, SCIURINI)

Resumo

Tree squirrels are conspicuous inhabitants of all Neotropical forest biomes, but in contrast to other widespread rodent groups, they have been largely neglected in taxonomic and phylogenetic studies. Basic information on the number of genera and species is still ambiguous for the group — 15 to 35 species have been recognized in three to eight genera, depending on the author — and their phylogenetic relationships remain poorly understood. This project outlines a pioneering effort to provide a comprehensive phylogeny of Neotropical tree squirrels. Herein we present the first insights into their evolutionary history based on a phylogenetic analysis generated from high-throughput sequencing of mitogenomes from about 200 modern and historical samples obtained in 27 collections. Our results confirmed the tribe Sciurini as a monophyletic group with full support. The first lineage to diverge within the tribe was the North-American genus Tamiasciurus, followed by two Eurasian radiations – the genus Rheithrosciurus and a clade including Sciurus lis and S. vulgaris. Subsequently, the North-American species of Sciurus composed two distinct well supported clades. Central-American specimens plus two specimens from Ecuador compose a monophyletic group, which includes taxa currently placed in four different genera. Sister to this clade is the South-American group, which is structured in six main clades, not fully correspondent with any generic arrangement ever proposed. Regardless of the taxonomic discordances, our results are biogeographically consistent. For example, most of Northern South-American highland taxa (from Panama, Colombia and Ecuador) are clustered together; trans-Andean taxa from the cost of Ecuador and Peru are monophyletic; and lowland Amazonian forms (including the largest and some of the smaller species) are closely related. These results provide new perspectives into the diversification of Sciurini and will offer a sound basis for a forthcoming comprehensive taxonomic review of the group.

Palavras-chave

biogeography, rodents, South America, systematics, taxonomy

Financiamento

Conselho Nacional de Pesquisa e Desenvolvimento Científico (CNPq), Smithsonian Institution, American Society of Mammalogists, National Geographic Society.