The science behind domestication

My favorite part about going home is seeing my dog, a five-year-old golden retriever, overjoyed at seeing me. She wags her tail, rolls on the floor, brings me her favorite toy(s) and won’t leave my side.

Her traits of joy and adoration at my return are ones that many pet owners can relate to (sometimes even the owners of cats, typically much less exuberant than their canine counterparts).

And, as it turns out, her reaction may be more than just her general personality — it may be a particular set of genes.

The search to finding these genes takes two scientists to Novosibirsk in southern Siberia, where a small farm is home to several foxes being studied. The leader of the study is Lyudmila Trut, following in the footsteps of her late mentor, Dimitry Belyaev.

Belyaev secretly studied the silver fox, a close cousin of dogs, while under Soviet rule, which prohibited research into genetic sciences. Trut was Belyaev’s grad assistant beginning in the late 1950s. Their experiments with several generations of foxes astounded them.

As they picked out those foxes that were deemed “most approachable,” they found that the foxes being produced weren’t afraid of humans and actively sought to bond with them. It wasn’t just foxes, either — the experiment was reproduced with minks and rats.

Belyaev had a theory: domestication wasn’t just in the friendly nature of the animals, but that they were part of the molecular network across any animal species.

This is not the first time the theory has been introduced. Darwin documented in his “The Variation of Animals and Plants Under Domestication” that domesticated animals tend to be smaller, with floppier ears and curlier tails than their wild counterparts. These, among other traits, are occasionally called the “domestication phenotype.”

Dogs, like mine (pictured), are also apparently genetically disposed to staring like this when you have food.

Trut and Anna Kukekova, a post-doctorate in molecular genetics at Cornell, continue Belyaev’s work today.

Looking at both the tame and friendly foxes, as well as the pre-selected aggressive foxes also on the farm, Trut and Kukekova are aiming to link behavior to genes. They are seeking to find the genes responsible for creating the friendly versus aggressive behaviors, then test if those genes are also the ones behind the floppy ears and curly tails often seen on domesticated animals. Even then, their work wouldn’t be quite finished.

The goal would be to, eventually, find similar genes in what National Geographic calls the “most thoroughly domesticated species of all: human beings.”

To learn more about Trut and Kukekova’s work, along with other theories on domestication featured in a National Geographic article, click here

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