Extensive Phenotypic Diversity among South Chinese Dogs

We describe here a broad diversity in phenotype among dogs in southern China’s rural areas, previously relatively unknown outside of China. These dogs display a much broader spectrum of diversity than is observed for the Indian Pariah Dog and the Australian Dingo, which are of a more uniform type and popularly thought to be typical for South Asian dogs and to represent the primitive morphology of the earliest domestic dogs. We show here that the village dog population of southern China harbors a broad diversity of morphological features, for color, body structure and size, coat texture, ear, and tail set, that are otherwise typically associated with the wide variety of Western dog breeds and assumed to be the result of intense selective breeding. The diversity of southern China’s dogs is cast in the light of mtDNA and Y-chromosome DNA studies showing that the genetic diversity is distinctly higher in southern East Asia than in the rest of the world, indicating that this was the geographical origins of today’s dog. These data suggest that the diverse morphologies of European dogs may have been formed from genetic “building blocks" still present in the dog population of rural southern China. 1. Introduction Recent publications have shown that dogs in southern East Asia (China south of the Yangtze River and southeast Asia) harbor practically the full genetic diversity for mitochondrial DNA (mtDNA) [1, 2] as well as Y-chromosomal DNA [3], while all other indigenous dog populations across the world harbor just a subset of the gene pool found in southern East Asia (Figure 1). Consequently, the genetic diversity for these markers is distinctly higher for dogs in southern East Asia than in all other dog populations across the world. Most noticeably, in the universal dog gene pool there are 10 principal genetic groups of mtDNA, and all these groups have been found in southern East Asia, while only subsets of this gene pool were found in other regions, for example, Europe (4 of the 10 groups), Southwest Asia (5), and north China (5). This gives a strong indication that today’s Domestic Dog (Canis familiaris) originated from wolves in southern Eastern Asia, thus suggesting a region not previously thought to be the place of dog origins. The previously most prominent theories about dog origins were based on the archaeological record and proposed that dogs originated from either Southwest Asia or Europe, or from several separate regions, since the earliest reasonably firm evidence of domestic dogs are from Southwest Asia [4, 5] and Europe [6, 7]. However,