Compressing evoluton - Foxes to Dogs
This is part 2 of the 2-part series on "What appears cute to us, and what doesn't?"
The pictures above show the results of a remarkable but somewhat crazy experiment.
In 1958, Dmitri Belyaev and his intern Lyudmila Trut travelled to fur farms from Siberia to Moscow to Estonia, and selected 130 foxes (100 vixens and 30 male) who were friendlier and more docile around humans, to be first-generation parents for a breeding experiment.
When the cubs from these 130 foxes were born, Belyaev and Trut introduced human interaction, hand-feeding and petting (foxes would normally have no human interaction). Cubs which continued to show aggression, even after significant human contact, were discarded (i.e. sadly slaughtered and made into fur coats). The 10% of the second generation that was tamest were used as parents for the third generation; the tamest 10% of the third generation were then bred as parents for the fourth generation, and so on.
By intense selective breeding, an evolutionary process that might have otherwise require several millennia to unfold was compressed into a few decades. Within 4 generations, the cubs began to behave more like dogs. They wagged their tails and eagerly sought contact with humans. After 40 generations, the foxes were playful, friendly and behaved just like domesticated dogs. The foxes could "read" human cues and respond correctly to gestures or glances. Their vocalisations became different from wild foxes. And most incredibly, their appearance changed dramatically - legs and snout shortened, the jaw and skull grew wider, their tails, just like domesticated dogs and pigs, grew curlier. Remarkably, even they're fur had changed to a lighter, friendlier colour, instead of the more menacing and aggressive black and grey.
In short, they grew cute.
Isn't it wondrous these foxes that were specifically bred for human interaction evolved not just in behaviour? Sure we can imagine that animals can be trained to trust humans and become playful. But it was more than that - they evolved in appearance for no other functional purpose, except to be more attractive to humans.
How does nature know what is attractive to us?
How could foxes, genetically different, become so much like dogs?
The answer lies in the field of epigenetics - how we can become very different not because of the genes themselves, but because of how genes are expressed based on interaction with the environment.
You can read more about epigenetics here.
In this piece, we examined how nature changed in a very fundamental way, a deliberate compressing of what would have been centuries or millennia of evolution into just a few tens of years.