Credit: Stephen D. Nash/IUCN/SSC Primate Specialist Group

The number of giant lemurs in Madagascar may have been low even before humans pushed them to extinction.

Living lemur populations are found only in Madagascar, with the heaviest species weighing at most 7 kilograms. Giant species weighed up to 160 kg and vanished from the island after humans arrived around 2,000 years ago. A team led by George Perry at Pennsylvania State University in University Park sequenced mitochondrial genomes from five extinct giant lemur species, including multiple samples from two species, Megaladapis edwardsi and Palaeopropithecus ingens (pictured). The authors found that both species had low genetic diversity — a sign of small population size.

The authors suggest that low population numbers, rather than large body size, made giant lemurs especially susceptible to extinction.

J. Hum. Evol. http://doi.org/xwh (2014)