Orangutan Genome Sequenced

Nature has published an article detailing the draft sequence of a Sumatran orang-utan genome. Unravelling an organism's genome reveals its complete DNA sequence, allowing us access to all of its hereditary information.

The paper (Locke et al., 2011) indicates that the genome of the Sumatran orang-utan has evolved more slowly than that of the other great apes. Geneticists can determine this sort of thing by looking at gene arrangement and, for example, whether or not individual sequences are duplicated or repeated. It also gives an estimate of the speciation time for the two orang-utan species, and suggests that they split from each other as recently as 400,000 years ago.

The team also studied short read sequence data, from both Sumatran and Bornean orang-utans, and found the Sumatran species to be more genetically diverse than the Bornean orang-utan. In a hypothetical situation where human impact couldn't influence the survival prospects of either species, this higher genetic diversity would give the Sumatran orangutan an advantage over the Bornean orangutan. This is because more genetically diverse populations are generally more able to adapt to a changing environment and better equipped to survive disease outbreaks. However, Sumatran orang-utan populations are suffering, with numbers thought to be as low as 7,000 indivuals, whereas the IUCN Red List website offers estimates of 45,000 - 69,000 for the Bornean orang-utan. Both species remain threatened by habitat loss and fragmentation, fires and poaching for the pet trade. Unfortuantely for the Sumatran orang-utan, these are things that are unlikely to be dodged by having a high genetic diversity, which means it's down to us to make sure we don't force the orang-utan into the dark depths of extinction.

(For more technical information, see the full paper: Locke et al., (2011)Comparative and demographic analysis of orang-utan genomes. Nature 469, 529–533.