herbivores rather than carnivores. The other main theory for the extinction was that it was due to the climate change brought on by the most recent ice age. Genetics The Tasmanian devil's genome was sequenced in 2010 by the Wellcome Trust Sanger Institute. Like all dasyurids, the devil has 14 chromosomes. Devils have a low genetic diversity compared to other Australian marsupials and placental carnivores; this is consistent with a founder effect as allelic size ranges were low and nearly continuous throughout all subpopulations measured. Allelic diversity was measured at 2.7–3.3 in the subpopulations sampled, and heterozygosity was in the range 0.386–0.467. According to a study by Menna Jones, "gene flow appears extensive up to ", meaning a high assignment rate to source or close neighbour populations "in agreement with movement data. At larger scales (), gene flow is reduced but there is no evidence for isolation by distance". Island effects may also have contributed to their low genetic diversity. Periods of low population density may also have created moderate population bottlenecks, reducing genetic diversity. Low genetic diversity is thought to have been a feature in the Tasmanian devil population since the mid-Holocene. Outbreaks of devil facial tumour disease (DFTD) cause an increase in inbreeding. A sub-population of devils in the north-west of the state is genetically distinct from other devils, but there is some exchange between the two groups. One strand conformation polymorphism analysis (OSCP) on the major histocompatibility complex (MHC) class I domain taken from various locations across Tasmania showed 25 different types, and showed a different pattern of MHC types in north-western Tasmania to eastern Tasmania. Those devils in the east of the state have less MHC diversity; 30% are of the same type as the tumour (type 1), and 24% are of type A. Seven of every ten devils in the east are of type A, D, G or 1, which are linked to DFTD; whereas only 55% of the western devils fall into these MHC categories. Of the 25 MHC types, 40% are exclusive to the western devils. Although the north-west population is less genetically diverse overall, it has higher MHC gene diversity, which allows them to mount an immune response to DFTD. According to this research, mixing the devils may increase the chance of disease. Of the fifteen different regions in Tasmania surveyed in this research, six were in the eastern half of the