Nadine van Reeuwijk

Populations of conservation concern are small and/or declining in numbers. Small, isolated populations suffer accelerated inbreeding and loss of genetic diversity leading to reduced reproductive fitness (inbreeding depression) and reduced ability to evolve in response to environmental change. Some conservation biologists have predicted that demographic and environmental stochasticity and catastrophes would usually drive populations to extinction before genetic factors become a problem. This prediction is not generally true, as the majority of endangered species have lower genetic diversity than related non-endangered species.

Given the dramatic decline in orang-utans during the past century, there is a strong chance that they have undergone a severe bottleneck. Although recent populations show a quite high genetic diversity, there should be evidence of even a much higher diversity 100 years ago. Therefore it would be interesting to know more about the genetic diversity in the past comparing to recent populations from Borneo and Sumatra and to test if there has been a bottleneck. This information will be useful for the conservation of orang-utans and establishing effective conservation measures.