The Foxes with Doggy-ears Meenakshi Bhatt   © Copyright 2022 by Meenakshi Bhatt

Photo courtesy of Pexels.

The name ‘farm-fox’ comes from the fact that the original subjects for the experiment were obtained from fox farms. Foxes were farmed for commercial purposes starting as early as the 1880s. On these farms, the foxes were raised for their fur.

Foxes were chosen for this study on the basis of only one feature: tamability, i.e., the behaviour that allowed them to be domesticated. Most of the foxes were aggressive towards humans who tried to approach them. Some foxes were afraid and cowered. A small minority of foxes, however, remained calm. These foxes that did not show aggression or fear, were selected for breeding in the study.

After these foxes were selected, docile males and females were allowed to mate. Their babies were also selected on the basis of the same behavioural characteristic of tamability. This selection was continued generation after generation. Some unique findings appeared.

In an experiment where tamability was the sole selection criterion, it was to be expected that successive generations of foxes would show increasing friendliness to humans. That is exactly what happened. More and more friendly foxes were born with time. They seemed to enjoy human company as demonstrated by licking, tail wagging and other behaviours. Some of them even started whining when their human friends were about to leave.

However, without actually trying to select for any particular physical features, the scientists saw that later generations of domesticated foxes started showing some unusual physical traits. Some of them developed floppy ears, just like some breeds of dogs. Some of them developed coat patterns that were similar to dogs. Other than these visible changes, there were physiologic changes, too.

One of the physiological changes that occurred was a fall in the level of serum cortisol. Cortisol is the stress hormone. Possibly a decrease in exposure to predators and other dangers in the domesticated environment contributed to this. The animals also developed a more prolonged reproductive period. These animals were also found to have higher levels of serotonin, named by some as the ‘feel-good hormone’. These were all amazing findings because the investigators had made no attempt to select foxes with any of these traits.

In short, though the scientists had merely tried to handpick those foxes who showed a particular behaviour without paying attention to any physical traits, these physical changes had automatically made an appearance after some generations.

These findings had previously been described by none other than Charles Darwin, the famous naturalist who contributed heavily to the field of evolutionary biology. He studied domestic species extensively and noticed a baffling phenomenon. He observed that domestic animals, of various species, demonstrated more tame behaviour, some changes in the colour of their coats (e.g., mottling), changes in the shape of their skull and sometimes changes in their ears (floppy ears) and their tails (curled tails), as compared to their wild counterparts. These physical characteristics, along with some associated physiological changes later came to be known as the ‘domestication syndrome’.

The Farm-Fox study did much to popularize the domestication syndrome. One of its biggest strengths has been that it has been running for decades. However, over time, some shortcomings of the study have been noted by other scientists. The initial foxes recruited for the study were not truly wild animals. They were foxes being bred on fur farms. On fur farms, foxes have been selectively bred for decades based on the quality of fur, size, friendliness, fertility, etc. Thus, farm foxes are already quite different from their wild versions.

Also, the initial sample size was not very large (one hundred and thirty foxes). With a small sample size, the ability to apply the results of a study to the general population becomes quite limited. In addition, there is inadequate data confirming domestication syndrome in other species.

Despite these controversies, and even if the domestication syndrome is not as prevalent as it has been thought to be, the Farm-Fox experiment points to the presence of a surprising phenomenon. When we go about selectively breeding friendly animals, then a few generations down the line we may end up with animals who are not just more friendly but also different-looking than their ancestors.

References

1. https://books.google.co.in/books?hl=en&lr=&id=_uON0AO7qwYC&oi=fnd&pg=PA1&ots=hreXzNDCeB&sig=Jv1y0zK_X0q7WHw61qlOS2wT_pY&redir_esc=y#v=onepage&q&f=false

2. https://www.jstor.org/stable/27857815?read-now=1&seq=1

3. https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(19)30302-7

4. https://www.washingtonpost.com/science/2019/12/03/tame-foxes-taught-us-about-animal-domestication-did-we-get-story-wrong/

*****

My name is Meenakshi Bhatt. I live in New Delhi, India. I have a background in Science, and I have started dabbling in creative writing quite recently. I submit essays and short stories to writing contests. I have written for an online magazine on various topics (as part of writing competitions); lac jewellery, Arthur Ashe, the Jim Crow laws, and poetry. I have also recently started writing a blog on Medium.