and alliance with dogs Pat Shipman argues that the domestication of the dog gave modern humans an advantage when hunting. Evidence shows the oldest remains of domesticated dogs were found in Belgium (31,700 BP) and in Siberia (33,000 BP). A survey of early sites of modern humans and Neanderthals with faunal remains across Spain, Portugal and France provided an overview of what modern humans and Neanderthals ate. Rabbit became more frequent, while large mammals – mainly eaten by the Neanderthals – became increasingly rare. In 2013, DNA testing on the "Altai dog", a paleolithic dog's remains from the Razboinichya Cave (Altai Mountains), has linked this 33,000-year-old dog with the present lineage of Canis familiaris. Interbreeding Interbreeding can account for only a certain degree of Neanderthal population decrease. A homogeneous absorption of an entire species is a rather unrealistic idea. This would also be counter to strict versions of the Recent African Origin, since it would imply that at least part of the genome of Europeans would descend from Neanderthals, whose ancestors left Africa at least 350,000 years ago. The most vocal proponent of the hybridization hypothesis is Erik Trinkaus of Washington University in St. Louis. Trinkaus claims various fossils as hybrid individuals, including the "child of Lagar Velho", a skeleton found at Lagar Velho in Portugal. In a 2006 publication co-authored by Trinkaus, the fossils found in 1952 in the cave of Peștera Muierilor, Romania, are likewise claimed as hybrids. Genetic studies indicate some form of hybridization between archaic humans and modern humans had taken place after modern humans emerged from Africa. An estimated 1–4% of the DNA in Europeans and Asians (e.g. French, Chinese and Papua probands) is non-modern, and shared with ancient Neanderthal DNA rather than with sub-Saharan Africans (e.g. Yoruba and San probands). Modern-human findings in Abrigo do Lagar Velho, Portugal allegedly featuring Neanderthal admixtures have been published. However, the interpretation of the Portuguese specimen is disputed. Jordan, in his work Neanderthal, points out that without some interbreeding, certain features on some "modern" skulls of Eastern European Cro-Magnon heritage are hard to explain. In another study, researchers have recently found in Peştera Muierilor, Romania, remains of European humans from ~37,000–42,000 years ago who possessed mostly diagnostic "modern" anatomical features, but also had distinct Neanderthal features not present in ancestral modern humans in Africa, including a large bulge at the back of the skull, a more prominent projection