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2021-07-23 18:50:21
In a famous experiment that began in the 1960s, a group of former Soviet scientists attempted to breed wild foxes to make them pets like dogs and cats. They selected the least aggressive individuals of the silver fox and bred them to tame them.
Although the Soviet Union later collapsed, the experiment was still passed on to successive generations of scientists, the silver fox population has now been bred for nearly 60 generations.
Scientists observed that as early as the 5th generation, foxes began to lose their wildness. By the 35th generation, they have reached an 80% tame level. And now, over 60 generations, silver foxes have grown to closely resemble domestic dogs.
They have a fat snout, soft ears, and even begin to bark. Foxes also know how to wrap around people and wag their tails to greet their owners from afar. Not only that, they are not afraid of strangers, can rush into their arms, kiss passionately.
Wild silver fox in the 1960s.
After 60 generations, these silver foxes were domesticated just like dogs.
Foxes are following in the footsteps of dogs
But perhaps without the need for human domestication, a new study now shows that rural UK red foxes are evolving themselves to be closer to humans in the wild. As these wild animals migrated from the forest to their city habitats, they began to develop domestic dog-like characteristics.
Lee Dugatkin, an evolutionary biologist at the University of Louisville, said:I’m not surprised but still very pleased. This is a ‘natural experiment’ that is very consistent with what the Russian experiment has found.”
New research on red foxes in the UK was carried out by Kevin Parsons, a Canadian evolutionary biologist who works at the University of Glasgow. When he arrived in this English city, Parsons was immediately surprised by the number of foxes he regularly saw on the streets of Glasgow, especially early in the morning.
“They passed by and stared at me as if to ask, ‘Why are you looking at me? Is there anything strange?‘,” Parsons recalls. “The foxes here are not afraid of humans.”
This piqued Parsons’ curiosity and he immediately remembered the experiment that Soviet scientists did. Parsons wondered: Are the red foxes in the UK evolving silently to adapt to their urban life?
To test the theory, he went to the National Museum of Scotland to retrieve a collection of fox skulls in England. Between 1971 and 1973, they collected a total of about 1500 red fox skulls in London and surrounding countryside in a campaign to destroy the species.
All skulls are marked where they were found, rural or urban. Urban areas are defined as having buildings, street lights and no tree areas, while rural areas are heavily wooded and lack human development.
Parsons imaged 57 female fox skulls and 54 male fox skulls to determine their key features. The results showed that the fox’s habitat exerted a significant influence on the shape of the skull.
Foxes living in cities, closer to humans, developed fox-like characteristics in the experiments of Soviet scientists. They have a significantly shorter and wider snout, and a smaller brain than their rural counterparts.
Both male and female foxes have very similar skull shapes. All these changes are typical of the domestication syndrome that Charles Darwin once articulated.
In a city environment, a fox can easily feed itself by rummaging through human trash cans.
When foxes live closer to people, their faces also look “cute”
In general, urban fox skulls are designed to deliver more powerful bites, according to Parsons’ analysis. In contrast, the skulls of rural foxes are more pointed, giving them absolute speed in the wild.
This may be because in a city environment, a fox can feed easily by rummaging through human trash, where they can find more bone fragments and require stronger teeth to bite.
As a result, short-nosed foxes also look friendly and “cute“than the long and pointed fox.”Although the change is not large, this shows that foxes are evolving and it is not a random process.“, Parsons said.
Like the first wolves, urban foxes have overcome their fear of humans to get close enough to our landfills. And that could be the first spark that leads to another kind of biological change.
Looking back over the past century, foxes have taken over London. Currently, one in 300 foxes in the UK lives in the capital. The number of foxes in London may have reached more than 10,000.
For more than 100 years, foxes have also roamed British cities, including Birmingham, Bristol and London. As a result, their diet has changed, with 37% of their diet coming from human landfills.
Since urban foxes tend to stay in their new homes, the chances of them remarrying with rural foxes are reduced. This means that foxes in the cities are continuing to breed themselves to evolve on their own, closer to humans and look better.cute” than.
Maybe one day, foxes can compete with cats and dogs to become human’s new pet.
Reference Science, Inverse
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