Dog domestication and human cultural evolution

In Jena fand vom 13. bis 15. September die Inaugural Cultural Evolution Society Conference statt, die vom Max Planck Institute for the Science of Human History veranstaltet wurde. Dort stellten Daniela Pörtl und Christoph Jung Aspekte ihres Models von der Activen Sozialen Domestikation des Hundes mit einem Poster vor. Hier den kurzen Vortrag, den Daniela Pörtl als Teilnehmerin der Konferenz hielt:

Dog domestication and human cultural evolution – co-evolution of cognitive abilities favoured by epigenetic modulations in limbic brain regions

Dogs are the first domesticated animals living together with humans at least 25.000 years - assisting humans until today with hunting, protecting, herding. But primarily dogs have always been important social bonding partners to humans. Recent scientific research proves mutual empathy between humans and dogs. Domestication evoked tameness, that means decreased flightdistance chiefly concerning to humans. And in fact, in the Siberian farm-fox experiment, demonstrating a domestication process, first changes have been found in a decreased activity of HPA stress axis promoting domestication syndrome. Now I will go on to present the hypothesis of the

Active Social Domestication (ASD) – an epigenetic based model of a self-domestication process due to interspecific emotional attachment

During the Palaeolithic period humans and wolves lived as cooperative hunters in similar family clans in the same ecological niche. Similar social skills and the evolutionary continuity of mammalian brains allowed both of them initial interspecific (pro)social communication achieving an evolutionary benefit for both. Knowing each other reduced stress and helped becoming confident. Behavioural cultures between wolf clans and human clans were formed, individual bonding, genetic isolation and domestication processes began.

Epigenetic modulation of stress axis caused by social behaviour

Scientific studies prove, that prosocial care enhances via epigenetic modulations glucocorticoid negative feedback loop in brain, thus decreasing the activity of stress axis and therefore increasing the activity of cross-regulated calming system. This suggests a direct relationship between variations in prosocial behaviour and development of HPA responses to stress. (These mechanisms are explained in more detail on the poster).
In the Palaeolithic period described epigenetic modulations induced lower cortisol levels in all individuals within the attached wolf-human clan, prosocial behaviour improved enhancing mutual empathy and interspecific in-group behaviour. Eventually the wild wolf became a tame wolf regarding known individual humans as his pack mates.

(Photo: Christoph Jung)

But a tame wolf is not yet a dog.

Permanent high cortisol levels impair learning and executive functions. But epigenetically decreased cortisol levels improve social learning capabilities and enabled tame wolves to develop increased emotional and cognitive empathy concerning to humans. Thus first dogs have learned to use human communicative cues and eventually dogs integrated themselves into human social structures, accepting humans as their preferred social binding partner.

But what about ancient humans? Did dogs domesticate humans as well?

During the dog domestication process all individuals of the attached human-wolf clan experienced the same epigenetic modulation of stress axis due to increased interspecific prosocial contacts. Hence it is reasonable to proclaim that the dog domestication had probably influenced human social and cognitive development as well. And in fact, within a narrow time frame of dog domestication, archaeologists describe a sudden further stage of human cultural development in the Aurignacien; first flutes, sculptures, cave paintings and javelin spins occurred. Thus it is reasonable to assume that dogs have influenced human cultural development not only with assisting humans, but also we provide that dogs improved human cognitive capabilities additionally in the sense of a human self domestication process, thus we can think about co-evolution.

And even today social interaction between humans and dogs still reduce stress in both of them and invigorate therefore social and learning abilities, which is known to be the reason of dog facilitated therapy in medical treatment.

Daniela Pörtl, MD Ärztin

References

• Pörtl D, Jung C. Dog domestication and human cultural evolution – co-evolution of cognitive abilities favoured by epigenetic modulations in limbic brain regions. Poster at Jena, Conference: Inaugural Cultural Evolution Society Conference, Affiliation: Max Planck Institute for the Science of Human History, DOI: 10.13140/RG.2.2.21759.71842
• Pörtl D, Jung C. Is dog domestication due to epigenetic modulation in brain? Dog behaviour Vol 3, No 2, 2017 (accepted 2017-08-14) DOI: http://doi.org/10.4454/db.v2i3
• Jung C, Pörtl D. The domestication from the wolf to the dog is based on coevolution. Dog behavior Vol 2, No 3 (2016) DOI: http://dx.doi.org/10.4454/db.v2i3.44
• Poertl D, Epigenetic regulation of the hypothalamic-pituitary-adrenal stress axis and its effects on social behaviour Exp Clin Endocrinol Diabetes 2013; 121 - OP5_29 DOI: 10.1055/s-0033-1336637
• Jung C, Pörtl D. Tierisch beste Freunde. Stuttgart: Schattauer 2015, ISBN 978-3-7945-3132-5
• Jung C, Pörtl D. Die aktive soziale Domestikation des Hundes. Norderstedt: Bod 2014,ISBN 978-3735718389