Both Dienkes and John Hawks have shared news about the latest research on the domestication of dogs. The researchers analyze 117 skulls of prehistoric canids from sites in Belgium, Ukraine and Russia. They conclude that a 31,700 year old canid from Belgium is ‘clearly different from the recent wolves, resembling most closely the prehistoric dogs.’
The draft can be found in the Journal of Archaeological Science under the title, “Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes.” If the dating, and phylogenetic analysis is correct, these remains makes them the oldest known remains of domesticated dog, pushing back domestication time by 17,700 years, since the second oldest known dog, found in Russia, dates to 14,000 years ago as explained by Carl Feagans.
Prehistoric dogs are distinguished from both prehistoric and extant wolves in having a shorter and broader snout, relatively wider brain cases, and a general reduction in skull size. Palaeolithic dogs in the study conform to this pattern. The researchers extended their anatomical analysis to mtDNA and stable isotopes on the Belgian samples. All fossil samples yielded unique DNA sequences, Dienekes pointed out the results:
“when compared to extant wolf and dog sequences available from GenBank, all seven haplotypes found in the Pleistocene samples were found to be unique and not described to date. This result is remarkable when considering the large number of wolf (~160) and particularly dog sequences (> 1,000 from almost all breeds known today) available in Genbank.”
What this indicates is that prehistoric canid diversity was much larger than it is now. That makes sense, part of the domestication process, i.e. selection for desirable traits, weeds out diversity. It is certainly possible that these dogs were one of the first domesticated canids. The isotopic analysis of the dog remains indicate that they ate large game like horse, musk ox and reindeer, but not fish or seafood.
The dog remains come from an adjacent horizon in the Goyet cave, Belgium where Middle and Upper Paleolithic artifacts were discovered along with numerous remains of ice age mammals. Some of the remains show percussion fractions, have cut marks, or display traces of ochre. Aurignacian ivory beads were also discovered. The ancient Belgian canids are considered to be domesticated dogs because of their anatomy, unique isotope profile (they were eating large game, presumably hunted by humans), and since the remains came from a cave with recurrent human occupations from the Pleniglacial until the Late Glacial. This is exciting, but the authors caution that it is not very clear from which horizon the artifacts and bones originate from, if the same horizon at all. I consider the association rather loose.
Also, as John Hawks wonders, why’s there almost a 20,000 year gap in the fossil record of the domesticated dog? Most people share Dienekes opinion that dogs are extremely advantageous, one would expect a consistent representation in the fossil record — not a massive intermission.
- M GERMONPRE, M SABLIN, R STEVENS, R HEDGES, M HOFREITER, M STILLER, V JAENICKEDESPRESE (2008). Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes Journal of Archaeological Science DOI: 10.1016/j.jas.2008.09.033