In the Ille Cave on the island of Palawan, two articulated phalanx bones were found amidst an assemblage of other animal bones and stone tools. They were smaller than mainland tiger fossils, possibly due to insular dwarfism. It has been speculated that the tiger parts were either imported from elsewhere, or that the tiger colonised Palawan from Borneo before the Holocene. Fossil remains of tigers were also excavated in Sri Lanka, China, Japan and Sarawak dating to the Late Pliocene, Pleistocene and Early Holocene. Results of a phylogeographic study indicate that all living tigers had a common ancestor 108,000 to 72,000 years ago. The potential tiger range during the late Pleistocene and Holocene was predicted applying ecological niche modelling based on more than 500 tiger locality records combined with bioclimatic data. The resulting model shows a contiguous tiger range at the Last Glacial Maximum, indicating gene flow between tiger populations in mainland Asia. The Caspian tiger population was likely connected to the Bengal tiger population through corridors below elevations of in the Hindu Kush. The tiger populations on the Sunda Islands and mainland Asia were possibly separated during interglacial periods. The tiger's full genome sequence was published in 2013. It was found to have similar repeat composition to other cat genomes and an appreciably conserved synteny. Hybrids Captive tigers were bred with lions to create hybrids called liger and tigon. They share physical and behavioural qualities of both parent species. Breeding hybrids is now discouraged due to the emphasis on conservation. The liger is a cross between a male lion and a tigress. Ligers are typically between in length, and weigh between or more. Because the lion sire passes on a growth-promoting gene, but the corresponding growth-inhibiting gene from the female tiger is absent, ligers grow far larger than either parent species. The less common tigon is a cross between a lioness and a male tiger. Because the male tiger does not pass on a growth-promoting gene and the lioness passes on a growth inhibiting gene, tigons are around the same size as their parents. Some females are fertile and have occasionally given birth to litigons when mated to a male Asiatic lion. Description The tiger has a muscular body with strong forelimbs, a large head and a tail that is about half the length of its body. Its pelage colouration varies between shades of orange with a white underside