Editing Commensalism (section)

===Dogs and humans===
The [[dog]] was the first domesticated animal and was domesticated and widely established across [[Eurasia]] before the end of the [[Pleistocene]], well before the cultivation of crops or the [[domestication]] of other animals.<ref name=larson2012/> The dog is often hypothesised to be a classic example of a domestic animal that likely traveled a commensal pathway into domestication. Archaeological evidence, such as the [[Bonn–Oberkassel dog]] dating to ~14,000 BP,<ref name=janssens2018/> supports the hypothesis that dog domestication preceded the emergence of agriculture <ref name=vila1997/><ref name=thalmann2013/> and began close to the [[Last Glacial Maximum]] when hunter-gatherers preyed on [[megafauna]].

The wolves more likely drawn to human camps were the less aggressive, subdominant pack members with lowered flight response, higher stress thresholds, and less wary around humans, and therefore better candidates for domestication.<ref name=zeder2012/>
Proto-dogs might have taken advantage of carcasses left on site by early hunters, assisted in capturing prey, or provided defense from large competing predators at kills.<ref name=thalmann2013/> However, the extent to which proto-domestic wolves could have become dependent on this way of life prior to domestication and without human provisioning is unclear and highly debated. In contrast, [[cats]] may have become fully dependent on a commensal lifestyle before being domesticated by preying on other commensal animals, such as rats and mice, without any human provisioning. The debate over the extent to which some wolves were commensal with humans before domestication stems from the debate over the level of human intentionality in domestication, which remains untested.<ref name=larson2014/><ref name=hulmebeaman2016/>

The earliest sign of domestication in dogs was the [[Neoteny|neotenization]] (retaining juvenile features into adulthood) of skull morphology<ref name=morey1992/><ref name=trut1999/><ref name=zeder2012/> and the shortening of snout length that results in tooth crowding, reduction in tooth size, and a reduction in the number of teeth,<ref name=turnbull1974/><ref name=zeder2012/> which has been attributed to the strong selection for reduced aggression.<ref name=trut1999/><ref name=zeder2012/> This process may have begun during the initial commensal stage of dog domestication, even before humans began to be active partners in the process.<ref name=zeder2012/><ref name=larson2014/>

A [[Mitochondrion|mitochondrial]], microsatellite, and [[Y chromosome|Y-chromosome]] assessment of two wolf populations in North America combined with satellite [[telemetry]] data revealed significant genetic and morphological differences between one population that migrated with and preyed upon caribou and another territorial ecotype population that remained in a [[Taiga|boreal coniferous forest]]. Although these two populations spend a period of the year in the same place, and though there was evidence of gene flow between them, the difference in prey-habitat specialization has been sufficient to maintain genetic and even coloration divergence.<ref name=musiani2007/><ref name=larson2014/>

A different study has identified the remains of a population of extinct [[Pleistocene]] [[Beringian wolf|Beringian wolves]] with unique mitochondrial signatures. The skull shape, tooth wear, and [[isotopic signature]]s suggested these remains were derived from a population of specialist [[megafauna]] hunters and scavengers that became extinct while less specialized wolf [[ecotype]]s survived.<ref name=leonard2007/><ref name=larson2014/> Analogous to the modern wolf ecotype that has evolved to track and prey upon caribou, a Pleistocene wolf population could have begun following mobile [[hunter-gatherer]]s, thus slowly acquiring genetic and [[Phenotype|phenotypic]] differences that would have allowed them to adapt to the [[human habitat]] more successfully.<ref name=wolpert2013/><ref name=larson2014/>