But for Belyaev and Trut, the science was too important to leave undone. Although working in Siberia helped them fly under Lysenko’s radar, it was still a dangerous business. The very year they began, Nikita Khrushchev, under Lysenko’s spell, visited the institute where the experiment was housed and came within a hair’s breadth of shutting it down.
But on the experiment went. Since its inception in 1959, Trut, Belyaev, and their team of Russian biologists have raised tens of thousands of foxes, breeding approximately the sweetest and calmest 10 percent of each generation. (Belyaev died in 1985, but Trut, who recently turned 85 years old, continues to lead the experiment to this day.) Within six years — six fox generations — they had gone from wild animals that fled from humans, attacked when cornered, or both to foxes that begged for belly rubs, wagged their tails when Trut approached, and whined when she left. A few years later, there were foxes with floppy ears, curly tails, and mutt-like fur. Next came rounded, short, dog-like snouts. The foxes became more carefree with each generation, the result of more serotonin, a “happiness chemical,” coursing through their systems. They also had markedly reduced stress hormone levels than their cousins in the wild. They even followed the gaze of people — which is almost unheard for animals, except dogs.
As Belyaev predicted, all these changes are the result of selection for friendliness and friendliness alone.
And a paper they published on the genetic analysis…
Red fox genome assembly identifies genomic regions associated with tame and aggressive behaviours
Strains of red fox ( Vulpes vulpes ) with markedly different behavioural phenotypes have been developed in the famous long-term selective breeding programme known as the Russian farm-fox experiment. Here we sequenced and assembled the red fox genome and re-sequenced a subset of foxes from the tame, aggressive and conventional farm-bred populations to identify genomic regions associated with the response to selection for behaviour. Analysis of the re-sequenced genomes identified 103 regions with either significantly decreased heterozygosity in one of the three populations or increased divergence between the populations. A strong positional candidate gene for tame behaviour was highlighted: SorCS1 , which encodes the main trafficking protein for AMPA glutamate receptors and neurexins and suggests a role for synaptic plasticity in fox domestication. Other regions identified as likely to have been under selection in foxes include genes implicated in human neurological disorders, mouse behaviour and dog domestication. The fox represents a powerful model for the genetic analysis of affiliative and aggressive behaviours that can benefit genetic studies of behaviour in dogs and other mammals, including humans.