Historical sources suggest wild dingoes were a valued food source in some but not all areas, and thus widely hunted, apparently by stalking and spearing adults (and sometimes ambushing them at waterholes), and stealing pups from dens (Breckwoldt, 1988). The pups (especially very young, fat ones) were a succulent delicacy, and highly sought after by Aboriginal hunters (e.g., Nind, 1831:29; Morgan, 1852:39; Giles, 1889:20; Tindale, 1974:109). Some groups, however, found dingo flesh unpalatable and hence regarded the animals as a low-ranked prey item (Meggitt, 1965). Others abhorred and/or prohibited the practice of consuming dingo meat (Kolig, 1978).

Numerous observers recorded that some dingo pups were kept alive specifically with the intention of raising them in human society (Meggitt, 1965). These so-called “camp dingoes” had varied roles in Indigenous communities (Meggitt, 1965; Gould, 1969, 1970; Jones, 1970; Hamilton, 1972; White, 1972; Kolig, 1973; Macintosh, 1974; Hayden, 1975; Macintosh, 1975; Barker and Macintosh, 1979; Gould, 1980; Gollan, 1982, 1984; Breckwoldt, 1988; Rose, 1992; Corbett, 1995; Meehan et al., 1999; Smith and Litchfield, 2009; Cahir and Clark, 2013; Smith, 2015b; Balme and O’Connor, 2016; Koungoulos, 2017; Shipman, 2020; Koungoulos and Fillios, 2020a,b; Brumm, 2021; Koungoulos, 2021, 2022; Shipman, 2021; Brumm and Koungoulos, 2022). Some early writers commented on the practical value these animals had as hunting aides (e.g., Dawson, 1881; Giles, 1889:20), although there is continuing debate on this subject (Balme and O’Connor, 2016; Koungoulos and Fillios, 2020a; Koungoulos and Fillios, 2020b). It was also recorded that dingoes served as sentries; protecting the community from malevolent spiritual forces as much as from human intruders (Kolig, 1973; Gould, 1980:23; Tonkinson, 1991:48; Meehan et al., 1999:93). They were also prized by some Aboriginal people as bed warmers (“living blankets”; Meggitt, 1965; Tindale, 1983/2005), and simply for their companionship (Basedow, 1925:118).

Most authorities agree that Aboriginal people did not intentionally control the breeding of camp dingoes (Smith and Litchfield, 2009; Shipman, 2020; but see below). Instead, the available accounts consistently state that they acquired dingo pups by conducting raids on wild dens (Dawson, 1830:176; Nind, 1831). Specific details about the den raids are lacking in most early accounts (Brumm, 2021). Kimber (1976:143) notes, however, that during the dingo whelping season in central Australia, ‘Walpiri and Pintubi men were energetic in their attempts to catch wild dingo pups’. At least in some areas, dingo den-raiding was a pre-planned, community-wide endevour. For example, the Pitjantjatjara people of central Australia organized special-purpose expeditions during the midwinter pup whelping season to raid wild dingo dens, with the intention of obtaining newborn pups as food and pets (Tindale, 1983/2005). This seasonal activity was linked to closely observed astronomical cues and deeply embedded in ceremonial life. Tindale recorded that the rise of the Pleiades open star cluster (the Seven Sisters) prompted the performance of a cycle of dingo increase ceremonies — sacred rites performed in order to promote the species’ continued fertility and abundance (see also Rose, 2012:56). Male initiation rites were also performed. Following these ceremonial activities, people would split into ‘small family and larger clan-like groups’ (Tindale, 1983/2005:374), each with recognized territories in which they were permitted to harvest dingo pups from wild dens.

Pups were usually taken from dens at a very young age, when they were pre-weaned, largely immobile, and completely dependent on parental care. As Smith comments:

Some evidence suggests that, upon raiding a den, the choice between which individuals within the litter of newborn pups were killed for food, and which would be kept alive to rear as companions in camp, was not necessarily an arbitrary one. For example, Pitjantjatjara people would usually kill most of the pups in the den for food, ‘but some particularly marked and semi-albinic animals may be kept’ (Tindale, 1983/2005:374). Similar practices were recorded among another inland desert people, the Ngaanyatjarra: ‘Normal wild [dingoes] are light brown in color but aborigines tend to select odd-colored variants from wild litters on which they feed’ (Tindale, 1974:Plate 79). In addition, Warlpiri people killed and ate weak or deformed pups (both male and female) they found, but they ‘kept unharmed the sound pups’ (Meggitt, 1965:14). Ethnographic evidence therefore seems to suggest that the den-raiding and pup-adoption practices of Aboriginal people involved a process of selection on morphology and other characteristics from the outset (Smith and Litchfield, 2009).

Pre-weaned pups that were taken from dens and selected to live with people as social companions were hand-reared with loving care and affection. Women most commonly undertook this surrogate “mothering” role (Nind, 1831:29; Mitchell, 1839:347). Favored pups were subjected to an intensive process of nurturing and socialization that involved: breast-feeding of pre-weaned pups (Mitchell, 1839:347; Grey, 1841:279; Hamlyn-Harris, 1918:5); continuous ‘petting and pampering’ (Basedow, 1925:118); grooming pups for parasites (Hamilton, 1972:288); and carrying them around in the same position as (and commonly alongside) human babies (Hamilton, 1972:288).

Reports describe the strong emotional attachments between camp dingoes and their adoptive parents or carers (Balme and O’Connor, 2016). Unlike other animals kept as pets (Philip and Garden, 2016), camp dingoes were given personal names and kin classifications that placed them within a web of social relations with humans (Thomson, 1957:18; Rose, 1992:176). They also lived and slept together with their carers and wider human family, and were reputedly ‘indulged’ (that is, played with and coddled incessantly) as though they were small children (e.g., Krefft, 1865:372; Mathew, 1910:79). When the human-reared dingoes died, their human family mourned their loss with profound grief (Curr, 1886:47). Dingo burials (both with and without people) are known from the archeological record (Gunn et al., 2010; Koungoulos and Fillios, 2020b), although they are poorly studied (Koungoulos, 2021). It is also known that dingoes have prominent and varied roles in the cosmologies of many Aboriginal groups, including as mythological figures (Kolig, 1973; Rose, 1992; McIntosh, 1999).

Despite all this, historical accounts and anthropological observations suggest a consistent cultural pattern in which very young pups were intensely nurtured and doted upon, well-fed and so on, but as they grew out of the cute puppyhood phase — and thus presumably became less appealing as objects of human affection — they were largely left to fend for themselves (Meggitt, 1965; Meehan et al., 1999). These dingoes appear to have still been physically and sexually immature, but they were no longer actively provisioned by humans and hence had to survive by scavenging and scrounging discarded food remains. European observers commonly portrayed these dingoes as appearing to be severely emaciated (e.g., Mitchell, 1839:102–103). For example, at one desert camp Gould (1970:65) described an elderly woman’s coterie of pet dingoes as ‘the skinniest dogs I have ever seen’ (Gould, 1970:65). Early written accounts suggest that the hungry young dingoes often left camp to hunt for themselves, but were so closely bonded to humans that they would return to camp after a few days (Nind, 1831:29). Notably, most observations of this sort were made in the arid zones of Australia’s interior, especially deserts, where food is scarce. It is unclear if the same pattern was at play in more resource-rich parts of the country (Meggitt, 1965:17).

The early writers are largely silent on this issue of what happened to the young socialized companion dingoes when they were physically mature. To our knowledge, there are few confirmed observations of breeding-age females or adult males consistently being present in Aboriginal camps (Brumm, 2021; Koungoulos, 2021, 2022). It should be noted that there is little evidence to suggest that Aboriginal people slaughtered camp-living dingoes with the intention of consuming them, except during times of extreme hardship — and even then with great reluctance (e.g., Gould, 1980:241). Dingo body parts (skins, teeth, bones, and so on) were observed in use as material culture items (e.g., dingo tail headbands) in various parts of Australia (for detailed reviews of such uses see Philip, 2016 and Koungoulos, 2021). However, there are no indications either from available ethnographic accounts or the archeological record that Aboriginal people consistently used the remains of human-reared dingoes as culturally modified objects — which might have provided a motivation for harvesting pups raised in captivity (e.g., Germonpré et al., 2018). In cold areas, warm garments like cloaks and rugs were fashioned from possum skins (Wright, 1979). In modern Aboriginal communities there are often prohibitions against killing dogs: ‘To harm one, even by accident, is a serious offense punishable by a fine of hundreds of dollars and a public beating’ (McIntosh, 1999:188). According to Gould (1980:246), ‘there is every reason to think that this was true for dingoes in pre-contact times as well’.

The most commonly held notion among present-day scholars — based principally on the testimony of Aboriginal informants — is that when human-raised dingoes reached reproductive age (~12–24 months) they reverted permanently to the wild to breed (Meggitt, 1965; see also Lumholtz, 1889:196; Thomson, 1957:16; Hamilton, 1972:288; Meehan et al., 1999:92–93). The question remains: if the tamed and socialized camp dingoes had access to a regular source of human-derived food as they got older, would they have chosen to remain with their adoptive human family? There is evidence to suggest that some Aboriginal groups may not necessarily have favored such an outcome. Certain communities had a cultural prohibition against mature dingoes residing in camp because the reproductive behavior of these canids (e.g., incestuous coupling) diverged so dramatically from that of humans (Kolig, 1978; Tonkinson, 1991:22; Rose, 1992). Camp dingoes that did not revert to the wild when they reached breeding age may have been ousted or killed for this reason. According to the traditional exegesis of the Yarralin (northern Australia), dingoes who would not leave when they became sexually active ‘were destroyed by a poison derived from an orchid’ (Rose, 1992:176).

Exceptions to the above pattern may have been found in recent pre-colonial southeastern Australia, broadly defined as the area approximately between Adelaide and Sydney, bounded on the west by the limits of the Murray-Darling river system and in the south and east by the coastline (Figure 2). Within this region, deceased tame dingoes were frequently buried via inhumation in the same manner, and often alongside, Aboriginal people (Pardoe, 1996), constituting a tradition apparently unique to this part of the Australian continent and communicating the importance of tame dingoes to local communities. An osteometric study of a small subset of these individuals identified that some of them had reached or were long past the onset of sexual maturity, and that some displayed morphological alterations from the (otherwise highly conservative) wild morphotype, suggestive of isolated reproductive pools centered around Aboriginal settlements (Gollan, 1982). These changes included reductions in the gross size of dentition, and a pronounced gracility of size and shape in cranial proportions; most notably shortened and broadened rostrum, steeper face and brow, rounded and shortened calvarium, reduced sagittal and nuchal cresting. Together these traits are reminiscent of domestication-related morphological changes noted between dogs and wolves (Drake et al., 2015; Geiger et al., 2017; Galeta et al., 2021).

The question of whether such individuals were domesticated depends on the definition employed. In the biological sense focusing on presence of phenotype changes, the evidence is equivocal. The reproduction of tame dingoes within the camp is entirely plausible given the long-term residences of individuals for years into reproductive maturity and the occasional presence of puppy remains, but there is no evidence that there was any degree of human influence over this process. The morphological changes ostensibly resulting from domestication-related selection are variable, and their origin poorly understood. The clearest cases of dental reduction and altered cranial proportions seemingly did not occur within the same individuals, and potentially were driven by unrelated processes that could reflect epigenetic or early developmental factors rather than impacts of long-term selection (Koungoulos, 2021). They may potentially also relate to deep-rooted genetic divergences that are unrelated to human influence and predate these specimens by thousands of years (Koungoulos, 2021). Finally, most specimens assessed by Gollan (1982) showed no phenotypic difference to wild dingoes, despite signs of anthropogenic influences on their diet, indicating they were most likely born to wild parents lacking a history of anthropogenic selection. This suggests that in the long-term camp-dwelling dingo populations could not be sustained by internal reproduction and required replenishment from wild dens, probably owing to high juvenile mortality and adult dispersal.

Conversely, envisioning domestication as a social or cultural process based on enduring relationships between animals and people (Bogaard et al., 2021; Losey, 2022), it would seem that tame dingoes which did not depart the camp but willingly accompanied people for the duration of their lives were not functionally distinct from the undifferentiated free-ranging domestic dogs found in many other Asia-Pacific societies. Although notable differences in disposition, intelligence, and independence probably existed between these dingoes and modern domestic dogs, these individuals had successfully become adapted to life alongside people in a domestic environment. This is particularly notable because this seems to have also been achieved without the use of physical confinements – an enormous challenge for modern dingo-keepers (Brumm and Koungoulos, 2022). Although specific evolutionary or physiological mechanisms generating changes in the morphology of some tamed dingoes are presently not understood, they are not observed in wholly-wild dingo populations and should be regarded as the eventual result of inter-generational dingoes reproducing within camps, or the sourcing of wild-born pups from parents who had previously been raised in camps.

Gollan (1982) speculated that aspects of the mobility and food-procurement pathways characteristic of Aboriginal societies in southeastern Australia were responsible for facilitating the long-term retention of dingoes within or around Aboriginal camps. Koungoulos (2022) has expanded upon this notion, arguing that a particular confluence of social and economic factors was conducive to the long-term management of tame dingoes and the emergence of altered phenotypes among them. Southeastern Australia was home to the largest, densest, and least mobile Aboriginal communities in the continent (Clarke, 2009; Pate and Owen, 2014; Pardoe and Hutton, 2020). The demography and lifestyles of these communities were supported by a well-watered and productive landscape offering abundances of aquatic animals and carbohydrate-rich wetland plants, and in the lower reaches of rivers estuarine and marine resources could also be accessed (Clarke, 2002; Pate, 2017).

Abundance of fish in particular offered a reliable resource base which could be used to provision large and long-term populations of camp dingoes as an alternative to sacrificing terrestrial dietary protein (and the valuable fats of mammalian and avian bone marrow) from the diets of people (Koungoulos, 2022). Two dingo burials studied by Gollan (1982) indeed had marine fish remains, presumably originating via human fishing, preserved in their stomachs. Marine and aquatic resources are frequently identified as important food bases for the management of prehistoric dogs in contexts outside Australia (Clark, 1997; Gonzalez et al., 2013; Losey et al., 2013; Perri et al., 2019). The general abundance of faunal resources in these environments may have also furnished an attractive base of scavengeable discard material within and around Aboriginal occupational sites that lessened the impetus for tame dingoes to stray far from the camp for self-foraged sustenance (particularly while raising pups).

Within such a landscape where larger, more closely-spaced and longer-resident Aboriginal communities were practicing the annual rearing of dingoes taken from dens, the relative probability of human influence acting inter-generationally upon these dingoes must have been greater. This could be because settlements were, through the availability of resources, more capable of sustaining several generations of tame dingoes reproducing within their confines if so desired. More interestingly, pups born to formerly tame dingoes which had left the camp to reproduce in the wild would also have had a greater chance of being subsequently collected from the den by members of the same community or a neighboring one for taming (Brumm, 2021) — by virtue of there being more settlements within close proximity to available denning locations, more people seeking to collect dingo pups, and their being more likely to do so within the same localities year-after-year (Koungoulos, 2022). If this same pattern was repeated over many generations, then a longstanding practice of raiding dens for pups and hand-rearing the favored ones may have modified the genetic makeup of the wider dingo population, even if the socialized canids typically dispersed into the wild when they were sexually mature (Brumm, 2021). Regardless of whether pre-contact southeastern tamed dingoes qualified as “domesticated,” their life-histories are of clear relevance to discussions regarding human-canid interactions potentially leading to domestication and the development of “dogs” which complete their life-cycles within a domestic setting.

A vital component of the early human-wolf association based on capturing and raising wild pups is the nature of the relationship between humans and the socialized wolves once they attained breeding age. We contend that when a wild-caught socialized wolf reached sexual maturity it generally would have had a strong natural tendency to revert to the wild to breed. This is in keeping with our knowledge of modern wolf social ecology, wherein a young wolf of breeding age typically disperses from its natal pack to find a mate (Mech and Boitani, 2003). However, wolf behavior is flexible enough (da Silva Vasconcellos et al., 2012; Packard, 2012) that some individuals would probably not disperse if they could find appropriate sexual partners in the camp sites. The socialized wolves that were leaving Upper Paleolithic communities when they matured sexually were likely then in a natural life-history transition that would have been difficult for humans to circumvent. As noted, this behavior appears to have been commonplace among camp dingoes in Australia: indeed, some Aboriginal groups seem to have accepted that it was the “dingo way” to follow “the call of the wild” (i.e., revert to the bush to reproduce), and did not attempt to prevent the animals from departing. In some cases Indigenous foragers may even have actively encouraged hand-reared canids to return to the wild, ostensibly because the sexual behavior of dingoes transgressed the laws of human morality (Rose, 1992).

We agree with Mech and Janssens’s (2022) argument that socialized adult wolves that escaped or were released from camp, and which established their territory in areas with easy access to human occupation areas or kill sites, were likely to have denned and whelped in proximity to humans. Unsocialized wolves are unlikely to have displayed this behavior owing to their natural fear of humans (Sazatornil et al., 2016:108). If socialized adult wolves that reverted to the wild lacked the propensity to segregate their breeding sites from humans then it is reasonable to assume that their dens would have been more easily accessible to humans than those of unsocialized wolves, as was conceivably the case with dingoes in Australia (Brumm, 2021; Koungoulos, 2021, 2022). Consequently, we can think of dens used by “re-wilded” socialized wolves in the vicinity of human settlement sites, which can be considered as anthropogenic habitat “islands” (cf. Spengler, 2022), as being in a liminal zone between the environment inhabited by strictly wild-living (unsocialized) wolves and the camp sites occupied by humans.

It follows that if camp-living and dispersing socialized wolves commonly formed mated pairs with each other, then any offspring they produced are likely to have inherited morphological and behavioral characteristics that had been under human selection in one or both parents. Hence, we surmise that a long-term pattern of hand-reared, socialized wolves breeding in liminal zones near human camps may have influenced the enrichment of genetic variants (i.e., caused genetic changes) in these populations.

We would expect this process to have begun to produce recognizable changes in wild wolf populations long before the first widely accepted remains of domestic dogs appear in the archeological record after the Last Glacial Maximum (LGM). Evidence for this is provided by the early appearance of dog-like skeletal remains in western Eurasian contexts (Germonpré et al., 2009, 2012, 2015a, 2018, 2021a; Ovodov et al., 2011). In the faunal assemblages of several early and middle Upper Paleolithic sites, two sympatric canid morphotypes have been described. The Pleistocene wolf morphotype is rather similar in shape and size to recent northern wild wolves from Eurasia. The Paleolithic dog type (also referred to variously as ‘protodog’ or ‘Palaeodog’; Figure 6) has a smaller skull and a shortened snout with a proportionally wide palate, and a higher and shorter lower jaw compared to the Pleistocene wolf type (Germonpré et al., 2017b; Galeta et al., 2021, 2022). It has been suggested that these altered craniodental features of the Palaeodogs could have been caused by the inadequate diet they received as pups or that their mothers received while carrying them in their womb (cf. Zeuner, 1954; Platt and Stewart, 1968), by a restricted mobility as they were tethered or kept enclosed, by inbreeding and/or by selective breeding based on the sociable traits in some of the pups (Germonpré et al., 2021a). Koungoulos (2021) has suggested that the Palaeodog morphotype may actually include socialized adult wolves that had reverted to the wild but remained in a relationship of commensalism with humans, as has been proposed for dingoes (Brumm, 2021).

The oldest known specimen of a Palaeodog identified thus far is from Goyet Cave in Belgium (35.7 kyr cal BP; Germonpré et al., 2009; Figure 6). We infer that by this early stage in the modern human occupation of Europe the practice of adopting wolf pups from liminal dens had begun to alter the genetic makeup of some wild wolf populations, at least in this part of western Eurasia, but possibly more widely. We think this process of humans inadvertently changing wolves through their practice of taking their young from dens to rear as pets had become more advanced by the Gravettian (~33–24 ka). At this stage, a key shift in the human-wolf relationship came into effect when large groups of mobile hunter-gatherers began gathering at aggregation sites at times when wolves were denning and whelping nearby.

In this regard, we draw attention to the large open-air mammoth “megasites” in central and eastern Europe (e.g., Předmostí, Dolní Věstonice, Yudinovo, Eliseevichi, Mezhirich; Figure 7). Dating from the Gravettian and Epigravettian, these probably represent large aggregation sites (Soffer, 1985; Oliva, 1997; Pidoplichko, 1998; Germonpré et al., 2008; Khlopachëv and Polkovnikova, 2017; Khlopachev, 2019; Sablin et al., forthcoming). Many of these impressive sites are characterized by direct or indirect evidence for mammoth hunting, as well as human burials, female anthropomorphic figurines, procurement of exotic materials and/or substantial architectural constructions made from mammoth bones (Germonpré et al., 2020, 2021b). At these locations, a surplus of mammoth meat enabled large numbers of foragers to gather recurrently for an extended period of time (Sablin et al., forthcoming; Germonpré et al., 2021b). Based on seasonality studies, it can be inferred that people were often concentrated at these sites during several seasons, including spring (Nývltová Fišáková, 2013; Germonpré et al., 2021b), precisely the time of year when wolves would have been denning and whelping (Mech and Boitani, 2003).

These sites are also notable for the presence of both Pleistocene wolves and Palaeodogs. Furthermore, these two morphotypes represent ecologically distinct populations that differ in their dental microwear textures (Prassack et al., 2020, 2021) and stable isotope ratios (Bocherens et al., 2015), suggesting that the Pleistocene wolves ate more suitable and softer food items that contained a large portion of mammoth meat compared to the Palaeodogs. The latter had more bones in their diet, which consisted mostly of reindeer and muskox (Bocherens et al., 2015; Prassack et al., 2020, 2021). Likely, the Pleistocene wolves scavenged mammoth carcasses at human kill sites, like other carnivores also did, while Palaeodogs were fed lean meat (Bocherens et al., 2015; Lahtinen et al., 2021). The analysis of the anatomically modern human mandible recovered from Předmostí suggests that this person ate mainly mammoth meat and had as well a portion of wolf meat in their diet; they did not eat meat from Palaeodogs, however (Bocherens et al., 2015; Germonpré et al., 2017a,b). Reindeer were also hunted at Předmostí, as shown by their cut-marked remains (e.g., astragali; Germonpré, unpublished data). Their fur and marrow in addition to their meat would have been very useful for the Gravettian inhabitants of the site.

Importantly, therefore, in some parts of the Late Pleistocene Eurasian landmass (e.g., the Moravian Gate and Russian Plain), by the Gravettian and Epigravettian periods, there may have been a continuous cycle of (1) mobile groups of hunter-gatherers returning regularly to specific congregation sites (e.g., Předmostí), accompanied by young socialized canids which they had obtained previously from liminal dens located in the vicinity of these seasonal camps; (2) some of these socialized canids of breeding age dispersing into the wild (i.e., “re-wilding”) from these seasonal camps; and (3) hunter-gatherers congregated at these campsites replenishing their supply of wolf pups by raiding liminal dens, a practice that is likely to have involved revisiting known denning areas they had targeted previously [On Ellesmere Island, Mech (2022) observed free-ranging wolves reusing the same two dens to rear their pups every year between 1987 and 2006, with the exception of 1990 and 1991; one particular cave den on the island seems to have been reused ‘for centuries’ (Packard, 2003:37)].

Such a pattern, if repeated over a number of generations, could have had a pronounced effect on the population of canids from which humans routinely acquired new pups (Figure 8). First of all, following Mech and Janssens’s (2022) model, we can expect that newly “re-wilded” socialized canids commonly formed mated pairs with other dispersing socialized wolves and/or with former socialized wolves that had dispersed during prior seasons, and which had now congregated near the human seasonal camps or with the tamed canids kept at the camp sites. These human-reared canids are likely to have marked-out territories in the vicinity of human settlements, a key source of food, and prevented wild wolves from encroaching (Mech and Janssens, 2022). Women and children, in particular, but also men, may have been motivated by emotional ties to re-establish close bonds of companionship and communication with the canids they had raised as pups and that had reverted to the wild in previous seasons, seeking them out and hand-feeding them to encourage these erstwhile human companions to stay close to socialize and play. Unsocialized, free-ranging wolves attracted to the area may have scavenged from the mammoth kill sites once humans abandoned them. These were located some distance from human camps.

Under this scenario, pups born at the camp sites or in liminal dens in these areas could have descended from lineages that had been subjected to many generations of unconscious human selection for particular morphological and behavioral traits, such as characteristics associated with tameness (e.g., increased sociability and playfulness). It therefore seems plausible that many pups taken from these dens could have displayed altered craniodental morphometry and body size reduction, resulting in the distinctive Palaeodog morphotype (Germonpré et al., 2009). Indeed, in the model proposed here, young socialized Palaeodogs probably would have been the canid type that was most commonly encountered in and around the large congregation sites, either as camp-living companions or in loose association with people (see also Koungoulos, 2021); both variants could have survived principally on food provided by humans (i.e., lean meat and bones from reindeer and muskoxen; Bocherens et al., 2015; Prassack et al., 2020, 2021).

Palaeodogs that had been hand-reared and socialized may still have been predisposed to disperse from human communities when they matured, forming mated pairs with socialized or unsocialized wolves, or socialized or unsocialized Palaeodogs – and giving birth in camp, in liminal dens, or further away in wild dens. Some of the dispersing socialized canids (both Palaeodogs and wolf types) may have roamed beyond the liminal zone into areas where they came into direct contact with packs of free-living, unsocialized wolves, forming mated pairs and interbreeding with them. Furthermore, humans gathered at the seasonal camps might have acquired some wolf pups from dens located further out in the non-anthropogenic or “wild” environment (perhaps because competition for pups from liminal dens was intense), bringing them back to camp to raise alongside pups born in the camps or obtained from the liminal zone (Figure 8).

Some Palaeodog lineages, having acquired more behavioral traits associated with domestication, may have been inclined to freely come and go from human camps as adults, or even to reside in them on a permanent or semi-permanent basis. Concerning the latter, it seems likely that the liminal zone was not a completely safe area for socialized canids that had dispersed from human communities. Dangerous predators such as cave hyaenas, cave lions, and brown bears could also have been visiting this zone and may have preyed on them. Some socialized adult canids could have managed in this environment, and hence their liminal dens could have been raided by humans. Others, however, were restrained to campsites or being flexible enough, had the ability to breed in the presence of humans and may have chosen to birth their pups inside the confines of hunter-gatherer campsites, where they were protected and cared for by humans and thus free from inter- and intra-specific competition (Germonpré et al., 2020, 2021a,b).

Even if so, however, the dingo model implies that Upper Paleolithic humans would have continually replenished (or augmented) their supply of wolf pups by raiding dens in the spring. As with dingoes, socialized adult wolves that remained in camp may have reproduced at a low rate in captivity. However, even if camp-living wolves did furnish humans with an adequate supply of new pups, the practice of raiding wild dens for more pups may have continued for non-utilitarian reasons. As the Yolngu example noted above suggests, perhaps den raids were still undertaken because they reinforced a perceived spiritual connection between humans and wild wolves. Whatever the case, we contend that the practice of den raiding and wild pup-raising was a long-term cultural tradition over large parts of Eurasia that was not confined to the earliest phases of dog domestication (Germonpré et al., 2012:195), as could be tacitly implied in the human-initiated model.

Such a complex human-canid relationship could have endured in different regions in parallel for a long period of time, slowly modifying the genes of the local wolf populations and leading to the development and retention of traits associated with domestication. However, the influx of wild wolf genes would account for the long road to genetic isolation. During den raids, moreover, it may not have been possible for humans to reliably distinguish between pups from the liminal dens and those from the wild dens. This would have permitted gene flow from the wild, thereby delaying reproductive isolation in socialized camp wolves as there were several possible sources of genetic input.

In sum, the onset of springtime aggregation by large groups of Upper Paleolithic hunter-gatherers may have initiated more pronounced genetic changes in the wild-living wolf population from which humans obtained their pups, changes that enabled people to more successfully keep the socialized adults in camp after they matured sexually. However, in-camp reproduction was probably a “work in progress.” Socialized canids would have frequently dispersed when they reached breeding age and the ongoing practice of den raiding in liminal zones meant that there was constant gene flow from the wild into any populations of camp-born canids (Figure 8).

Many Palaeodog lineages that emerged at or in the vicinity of human aggregation sites may have gone extinct. At least one lineage, however, if isolated reproductively for long enough (hundreds or thousands of years), could have given rise to the ancestors of modern domestic dogs. But this need not imply that dogs were domesticated from wolves in the central or eastern European region, or that the mammoth megasites on the Moravian Gate or Russian Plain per se are directly related to the beginnings of dog domestication. It could be the case, for example, that wolves were domesticated somewhere in Central or East Asia (e.g., Gojobori et al., 2021; Bergström et al., 2022; D’Huy, 2022). Even if so, we anticipate that the earliest domestic dog lineages emerged in similar circumstances to those outlined here.

In Australia, the special relationship between Aboriginal people and dingoes seems to have existed over a long period of time without resulting in the domestication of these wild-living canids (Brumm, 2021); although, as previously indicated, the situation in the southeastern region of the mainland may have been more complicated. So why was the situation different in Late Pleistocene Eurasia? How did a close and long-term dingo-like association between humans and wolves transform into a domestic one? What changed? Was there a threshold that was passed? How the final transition to a more controlled breeding occurred is uncertain, but it may be related to an increasing human population density which could have led to larger social networks and trading systems, furnishing people with more opportunities to exchange pups. This would have reduced the need to raid dens for newborn pups and resulted in a more profound genetic isolation between the emerging dogs and the Pleistocene wolves. Presumably, at a certain point the behavioral characteristics of the protodogs, descending from more isolated lineages, were becoming obviously advantageous compared to those of the socialized wolves, such that their owners took more effort to keep them separated from the wolves or culled hybrid pups.