From fossils to mitochondrial genomes: analyzing size variation in caviid rodents

PÉREZ, M. E.; VILELA, JÚLIO; DE OLIVEIRA, J.; LESSA, G.; PATTERSON, BRUCE

Minnesota

Congreso; 96th Annual Meeting of the American Society of Mammalogists; 2016

American Society of Mammalogists

The New World representatives of Hystricognathi, the Caviomorpha rodents, present agreat evolutionary history with relevant fossil records in South America since the Eocene.Many questions have been debated within the last decades concerning their arrival timeand pathways since lineage split from African relatives. This is also true for somecontentious relationships within superfamilies and genera. Besides still controversialaspects on the biogeography and evolution of Caviomorpha, some other questions remainunclear. One of these is the intriguing relationship within Cavioidea with the uncertainarrangement among Hydrochoerus and Kerodon, specifically considering their discrepantbody size. Although the close relationship is well supported by both morphological andmolecular characters, many interesting issues remain unanswered, for instance: whatcould be the ecological explanation to the size disparity between Hydrochoerus andKerodon. In an attempt to determine this, we are performing new phylogenetic analysesbased on a larger molecular dataset, composed by nuclear and mitochondrial genes.Besides the ethanol and nitrogen preserved samples, we additionally gathered some frommuscle ?crusties?. The vouchers accessed to obtain such material were dated from 1905to 1979. ?Ancient? DNA retrieved from such samples after library-prep were submittedto Illumina MiSeq (NGS). The assemblage of mitochondrial genomes, as well as genecapture procedures, are being carried on to increase taxon and gene sampling; leading toa new panorama to solve this puzzle.