When and How Did Wolves Become Dogs? | Science | Smithsonian
However long our association with dogs has gone on, we have altered them radically from The resulting differences between dogs and wolves are striking. Wolves (canis lupus), coyotes (canis latrans), and domestic dogs (canis familiaris) are closely-related species. All three can interbreed and produce viable, fertile offspring — wolfdogs, coywolves, and coydogs. Dogs and wolves are so closely related that DNA analysis cannot. cial behavior in relation to natural selec- tion. In this . it may explain the fact that highly different sorts of early difference between dogs and wolves appears.
Pugs and poodles may not look the part, but if you trace their lineages far enough back in time all dogs are descended from wolves. Gray wolves and dogs diverged from an extinct wolf species some 15, to 40, years ago. But controversies abound concerning where a long-feared animal first became our closest domestic partner. Genetic studies have pinpointed everywhere from southern China to Mongolia to Europe. Scientists cannot agree on the timing, either. Last summer, research reported in Nature Communications pushed likely dates for domestication further back into the past, suggesting that dogs were domesticated just once at least 20, but likely closer to 40, years ago.
Evolutionary ecologist Krishna R. Tracing genetic mutation rates in these genomes yielded the new date estimates. Veeramah in a release accompanying the study. In fact, at least one study has suggested that dogs could have been domesticated more than once. Researchers analyzed mitochondrial DNA sequences from remains of 59 European dogs aged 3, to 14, yearsand the full genome of a 4,year-old dog that was buried beneath the prehistoric mound monument at Newgrange, Ireland.
The many interbreedings of dogs and wolves also muddy the genetic waters, of course. Such events happen to the present day— even when the dogs in question are supposed to be stopping the wolves from eating livestock.
How did dogs become man's best friend? Perhaps more intriguing then exactly when or where dogs became domesticated is the question of how. Associated Data Video S1: The video illustrates the behaviour variables latency of eye-contact, struggling, biting and the behaviour of 8-week-old wolves in the proximal momentary pointing trials in Study 1.
The video illustrates the procedure of the distal momentary pointing and the behaviour of adult wolves in Study 3. To reconcile previously contradicting views on the origin of dogs' outstanding performance in utilizing human gestures, we suggest that dog-wolf differences should be studied in a more complex way.
Characteristic behavioural differences showed that for wolves it took longer to establish eye contact with the pointing experimenter, they struggled more with the handler, and pups also bit her more before focusing on the human's signal.
The performance of similarly hand-reared 8-week-old dogs and wolves did not differ in utilizing the simpler proximal momentary pointing. However, when tested with the distal momentary pointing, 4-month-old pet dogs outperformed the same aged hand reared wolves. Thus early and intensive socialisation does not diminish differences between young dogs and wolves in behaviour and performance. Socialised adult wolves performed similarly well as dogs in this task without pretraining. The success of adult wolves was accompanied with increased willingness to cooperate.
However, the delayed emergence of utilising human distal momentary pointing in wolves shows that these wild canines react to a lesser degree to intensive socialisation in contrast to dogs, which are able to control agonistic behaviours and inhibition of actions in a food related task early in development. Introduction Recent interest in the evolution of social cognitive abilities in animals puts the domestic dog at the forefront of research .
Dogs even have been found to perform better in some human related communicative tasks compared to chimpanzees .
The origin of this skill of dogs has mainly been discussed from an evolutionary point of view. Originally it was hypothesized that selection during domestication might have directly facilitated human-compatible social cognition in dogs . A more recent hypothesis has argued for indirect selection as an alternative explanation. More recently, one study found that intensive socialisation and regular training of wolves diminish some of the previously suspected differences in social cognitive skills between dogs and wolves.
This led the authors to emphasise the contribution of ontogenetic effects on the emergence of social skills in socialised dogs and wolves . Unfortunately, broadly presented theories have not always been supported by experimental data or the experimental procedures employed can be criticized [e.
For example, the claim about selection for decreased emotional reactivity has not been tested by behavioural observations in socialized wolves and dogs, nor has fearful or aggressive resistance to interaction with humans been shown to correlate at the individual level with the actual performance in communicative tasks . Similarly, there is little data on the social cognitive abilities of adult wolves, which would be necessary to investigate the effect of individual experiences .
Origin of the domestic dog
Unfortunately, results of the two studies on adult wolves available so far  cannot be used for comparisons with earlier developmental data because simpler versions of the pointing gesture were used. The study of Udell et al.
Moreover, Udell et al. Beyond the actual cognitive ability for relying on human directional signals these factors seem to have two main origins. Anthropogenic selective environment affected probably the mode of action in dogs by changing emotionality and reactivity to stimulation [for reviews see 6] in comparison to their ancestors. As a consequence dogs are generally predisposed to develop better skills for action inhibition that in a social context results in higher willingness for cooperation with humans.
Independently, selection has affected behavior systems dealing with the recognition of social partners and the minimally required amount of socialization. Thus it is expected that dogs exhibit epigenetically enhanced sensitivity for salient human communicative cues.
This is supported by differential attachment to humans in similarly socialized dogs and wolves and social environment-dependent variability in sensitivity to human communicative cues in wolves .
Origin of the domestic dog - Wikipedia
We suggest that positive feedback between evolutionary selective and ontogenetic processes contributed to the increased readiness of dogs to look at the human face providing the basis for complex forms of dog-human communication . Here we present new data which may enhance the plausibility of the synergistic hypothesis.
We have tested socialized wolves and pet dogs at three different ages in a two-way object choice task in order to reveal what kind of species-specific differences emerge and how they change over development.
The date estimated for the evolutionary divergence of a domestic lineage from a wild one does not necessarily indicate the start of the domestication process but it does provide an upper boundary. The divergence of the domestic horse from the lineage that led to the modern Przewalski's horse is estimated at 45, YBP but the archaeological record indicates 5, YBP. The variance could be due to the modern wild population not being the direct ancestor of the domestic one, or the impact of a split due to climate, topography, or other environmental changes.
The divergence time does not imply domestication during this specific period. The sample provided the first draft genome from the cell nucleus of a Pleistocene carnivore and the sequence was identified as belonging to Canis lupus.
The sequence indicated that the Taimyr-1 lineage was separate to modern wolves and dogs.
Using the Taimyr-1 specimen's radiocarbon date in addition to its genome sequence compared to that of a modern wolf, a direct estimate of the mutation rate in dogs and wolves could be made to calculate the time of divergence. The study calculated a mutation rate for the 7, YBP Neolithic dog and found that it matched the mutation rate of the Taimyr-1 specimen, and noted that this also matched the mutation rate for the Newgrange dog that had been calculated in an earlier study.
Using the 7, YBP specimen and this mutation rate, the dog-wolf divergence time is estimated to have occurred 36, YBP and this is consistent with the timing found with the Taimyr-1 specimen in an earlier study. The study identified six major dog yDNA haplogroups, of which two of these include the majority of modern dogs. The Newgrange dog fell into the most commonly occurring of these haplogroups. The two ancient German dogs fell into a haplogroup commonly found among dogs from the Middle East and Asia, with the Kirschbaum dog sharing a common male lineage with the extant Indian wolf.
The study concluded that at least 2 different male haplogroups existed in ancient Europe, and that the dog male lineage diverged from its nearest common ancestor shared with the gray wolf sometime between 68, YBP. Studies of modern grey wolves have identified distinct sub-populations that live in close proximity to each other. However, the geographic origin of this radiation is not known. Where the genetic divergence of dog and wolf took place remains controversial, with the most plausible proposals spanning Western Europe,   Central Asia,   and East Asia.
Ina study of the maternal mitochondrial genome indicated the origin in south-eastern Asia south of the Yangtze River as more dog haplogroups had been found there. Ina study using single nucleotide polymorphisms indicated that dogs originated in the Middle East due to the greater sharing of haplotypes between dogs and Middle Eastern gray wolves, else there may have been significant admixture between some regional breeds and regional wolves.
Ina study of maternal mDNA indicated that the dog diverged from its ancestor in East Asia because there were more dog mDNA haplotypes found there than in other parts of the world,  but this was rebutted because village dogs in Africa also show a similar haplotype diversity. Then, one of these lineages migrated back to northern China and admixed with endemic Asian lineages before migrating to the Americas.