Primate molecular divergence dates

OVERLAPPING AND SYNCHRONIZATION IN THE SONG OF THE INDRIS (Indri indri)

“…Loud singing in indris follows a sequential organization (Pollock, 1986), which shows evident species-and sex-specific features Gamba et al, 2011) and may serve conveying different messages (Bonadonna et al, 2013;Torti et al, 2013). We aimed to investigate whether the ability to synchronize calling during group chorusing, which may be a phylogenetic parallel to singing ability in humans, is present in Indri indri, a species who diverged from the human evolutionary path more than 65 million years ago (Steiper & Young, 2006). Singing synchronization was expressed by measuring the percentage of overlap showed by individual singers and by evaluating whether the timing of a song unit could predict the occurrence of a unit sung by another group-member.…”

Systematic and comparative morphologies of the extrinsic cardiac nervous system in lemurs (Primates: Strepsirrhini: Infraorder Lemuriformes, Gray, 1821) with evolutionary morphological implications

“…A through understanding of primate morphology is important because the primate ancestor diverged from the ancestor of the rodents, which includes the main experimental animals such as the rat, mouse, and rabbit. Entire (Kumar and Hedges, 1998;Steiper and Young, 2006;Horvath et al, 2008;Matsui et al, 2009). The strepsirrhini is composed of seven families split into three infraorders: two families of Lorisiformes, four families of Lemuriformes, and one family of Chiromyiformes.…”

Monkeys choose, but do not learn, through exclusion

“…To further evaluate the extent to which choice by exclusion leads to learning in non-humans we studied these processes in rhesus monkeys, a primate species that diverged from humans approximately 30 million years ago (Steiper & Young, 2006). In Experiment 1, we determined the proficiency of monkeys in choice by exclusion.…”