Those Domesticated Foxes of Siberia Never Stop Giving
Mapping the genetics of domestication
Posted Aug 13, 2018
I wanted to give readers a quick update to my March 27th post “Want to Build a Dog From a Fox? Here's How to Do It.”
In that post, I wrote “Tucked away in Siberia, there are furry, four-legged creatures with wagging tails and loving eyes that are as docile and friendly as any lapdog. But, despite appearances, these are not dogs—they are foxes. They are the result of the most astonishing experiment in breeding ever undertaken—imagine speeding up thousands of years of evolution into a few decades. In 1959, biologists Dmitri Belyaev and Lyudmila Trut set out to do just that, by starting with a few dozen silver foxes from fox farms in the USSR and attempting to recreate the evolution of wolves into dogs in real time in order to witness the process of domestication. Most accounts of the natural evolution of wolves place it over a span of about 15,000 years, but within a decade, Belyaev and Trut’s fox-breeding experiments had resulted in puppy-like foxes with piebald spots, curly tails, and, occasionally, droopy ears. Along with these physical changes came genetic and behavioral changes, as well. In this ongoing experiment, now nearing its 6th decade, foxes were bred using selection criteria for tameness, and with each generation, they became increasingly interested in human companionship.”
As science would have it, the domesticated foxes of Siberia never stop giving. In a paper published just this week in Nature: Ecology and Evolution, Anna Kukekova, Lyudmila Trut and a team of geneticists report on a molecular analysis suggesting that fox chromosome 15 is a hotspot for genetic signatures of domestication. In particular, they found that selection on a gene called SorCS is tied to tame behavior in the Siberian foxes. SorCS is associated with synaptic plasticity, that is, the strength of the signal transmitted across synapses—one component of how neurons talk to each other. Synaptic plasticity itself is associated with memory and learning, suggesting a link, albeit indirect, between learning, memory and the genetics behind domestication.
This is not to say the authors are suggesting a “gene for domestication.” They most assuredly are not. But the fact that we have reached the point of identifying "candidate genes" associated with domestication, a process that has been fundamental to our evolutionary trajectory as humans, is a tribute to the researchers involved in this work, the scientific process itself, and, of course, those adorable foxes in Siberia.
1. For more on the silver fox domestication experiment: Dugatkin, L. and Trut, L. (2017). How to Tame a Fox and Build a Dog (University of Chicago Press, 2017)
1. For more on the study discussed here: Kukekova et al. (2018). Red fox genome assembly identifies genomic regions associated with tame and aggressive behaviours. Nature: Ecology and Evolution. DOI: 10.1038/s41559-018-0611-6