Thursday, 14 February 2013

Southeast Asian Neolithic dogs

From the paper:
Nevertheless, the close phylogenetic clustering of haplotypes from Thailand, Brunei, Bali, and the Philippines suggests these populations originated from the same source, consistent with a single migration event, whereas the dingoes, NGSDs, and dogs from Taiwan appear sufficiently distinct from these to reflect a distinct migration event (Fig. 2b-c). The clustering of the three Island Southeast Asian populations with Thailand also was more consistent with origination from Mainland Southeast Asia than Taiwan (in agreement with mtDNA findings of Oskarsson et al. 2011).
In light of findings from the present study, it seems clear that both post-Victorian and Neolithic exchanges link eastern and western Eurasian dogs. However, the cause of post-Victorian haplotype sharing between Western breed dogs and Southeast Asian village dogs apparently reflects very recent introduction of Western dogs to the East rather than extraction of Eastern dogs to create Western breeds during the Victorian Era.
Specifically, our aging of this European haplogroup to 5,800 (±SE = 1750) or 8,400 (±SE = 2500) years (depending on the dingo calibration to 3,500 or 5,000 years, respectively) suggests that the connection between pre-Victorian European and Southeast Asian dogs traces only to the Neolithic period and is not of sufficient antiquity to support the hypothesis of a single origin of dogs from Southeast Asia. Thus, although future studies are needed to combine the Y SNPs and STR markers in a geographically broader sampling of dogs than was considered here, our findings support the hypothesis for a massive Neolithic expansion of dogs from Southeast Asia rather than a Paleolithic origin of dogs from this region.

This massive Neolithic expansion of Southeast Asian dogs is testable by looking at early European dogs; these ought not to belong to haplogroup H1. It would also be interesting to speculate about the trade routes and/or population movements that facilitated the spread of dogs from SE Asia to Europe during the Neolithic.

Mol Biol Evol (2013) doi: 10.1093/molbev/mst027

Y chromosome analysis of dingoes and Southeast Asian village dogs suggests a Neolithic continental expansion from Southeast Asia followed by multiple Austronesian dispersals

Benjamin N. Sacks et al.

Dogs originated >14,000 BP, but the location(s) where they first arose is uncertain. The earliest archaeological evidence of ancient dogs was discovered in Europe and the Middle East, some 5–7 millennia before that from Southeast Asia. However, mitochondrial DNA analyses suggest that most modern dogs derive from Southeast Asia, which has fueled the controversial hypothesis that dog domestication originated in this region despite the lack of supporting archaeological evidence. We propose and investigate with Y chromosomes an alternative hypothesis for the proximate origins of dogs from Southeast Asia--a massive Neolithic expansion of dogs from this region that largely replaced more primitive dogs to the west and north. Previous attempts to test matrilineal findings with independent patrilineal markers have lacked the necessary genealogical resolution and mutation rate estimates. Here, we used Y chromosome genotypes, composed of 29 SNPs and 5 STRs, from 338 Australian dingoes, New Guinea singing dogs, and village dogs from Island Southeast Asia, along with modern European breed dogs, to estimate the evolutionary mutation rates of Y chromosome STRs based on calibration to the independently known age of the dingo population. Dingoes exhibited a unique haplogroup characterized by a single distinguishing SNP mutation and 14 STR haplotypes. The age of the European haplogroup was estimated to be only 1.7 times older than that of the dingo population, suggesting an origin during the Neolithic rather than the Paleolithic (as predicted by the Southeast Asian origins hypothesis). We hypothesize that isolation of Neolithic dogs from wolves in Southeast Asia was a key step accelerating their phenotypic transformation, enhancing their value in trade and as cargo, and enabling them to rapidly expand and replace more primitive dogs to the West. Our findings also suggest that dingoes could have arrived in Australia directly from Taiwan, independently of later dispersals of dogs through Thailand to Island Southeast Asia.


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