Horses have been valued for their diversity of coat colour since prehistoric times; this is especially the case since their domestication in the Caspian steppe in ~3,500 BC. Although we can assume that human preferences were not constant, we have only anecdotal information about how domestic horses were influenced by humans. Our results from genotype analyses show a significant increase in spotted coats in early domestic horses (Copper Age to Iron Age). In contrast, medieval horses carried significantly fewer alleles for these phenotypes, whereas solid phenotypes (i.e., chestnut) became dominant. This shift may have been supported because of (i) pleiotropic disadvantages, (ii) a reduced need to separate domestic horses from their wild counterparts, (iii) a lower religious prestige, or (iv) novel developments in weaponry. These scenarios may have acted alone or in combination. However, the dominance of chestnut is a remarkable feature of the medieval horse population. ... In addition, we discovered that tobiano spotting, which only occurs in domestic horses and had thus far only been detected after 1500 BC, was present in the Eneolithic/Copper Age (Kazakhstan, cal. 3654–3630 BC, and Germany, cal. 3368–3101 BC). Similar to chestnut and sabino spotting, the tobiano phenotype appears to arise shortly after domestication, which is assumed to have started approximately 4000–3500 BC in the Ponto-Caspian steppe region (modern day Kazakhstan and Ukraine) . ... Moreover, the detection of the tobiano phenotype in two Eneolithic domestic horses from distant regions has important implications regarding the origins of horse domestication  and their subsequent distribution. It also supports previous claims that the emergence of domestic horses in Central Europe at the end of the fourth millennium BC was facilitated by introduced horses from the Ponto-Caspian steppe .Wutke, S. et al. Spotted phenotypes in horses lost attractiveness in the Middle Ages. Sci. Rep. 6, 38548; doi: 10.1038/srep38548 (2016).
Thursday, December 8, 2016
Middle Ages: rotten time to be a spotted horse
Scientific Reports has a new paper on the history of coat patterns in domesticated horses and the domestication process itself. Emphasis is mine: