Domesticated red fox

The domesticated red fox is a form of the wild red fox (Vulpes vulpes) which has been domesticated to an extent under laboratory conditions. They are the result of an experiment which was designed to demonstrate the power of selective breeding to transform species, as described by Charles Darwin in On the Origin of Species.[1] The experiment explored whether selection for behaviour rather than morphology may have been the process that had produced dogs from wolves, by recording the changes in foxes when in each generation only the most tame foxes were allowed to breed. Many of the descendant foxes became both tamer and more dog-like in morphology.[2][3]

Domesticated red fox
Domesticated
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Vulpes
Species:
V. vulpes
Binomial name
Vulpes vulpes

The program was started in 1959 in the Soviet Union by zoologist Dmitry Belyayev[2] and it has been in continuous operation since. Today, the experiment is under the supervision of Lyudmila Trut in Russia, at the Institute of Cytology and Genetics in Novosibirsk.[4][5][3]

In 2020, a review found that the results of the "Farm fox experiment" had been overstated, and that the "wild" population it was based on had originated from a captive population from Canada that had been bred there since the 1800s.[6]

Genetic experimentation

Initial premise and hypothesis

The experiment was initiated by scientists who were interested in the topic of domestication and the process by which wolves became domesticated dogs. They saw some retention of juvenile traits by adult dogs, both morphological ones, such as skulls that were unusually broad for their length, and behavioral ones, such as whining, barking, and submission.

For a time, when the fields of genetics and agriculture promoted Lysenkoism as an official state belief, Belyayev's commitment to classical genetics had cost him his job as head of the Department of Fur Animal Breeding at the Central Research Laboratory of Fur Breeding in Moscow in 1948.[7] During the 1950s, he continued to conduct genetic research, studying animal physiology.

Belyayev believed that the key factor selected for in the domestication of dogs was not size or fertility, but behavior: specifically, tameability.[8] Since behavior is rooted in biology, selecting for tameness and against aggression means selecting for physiological changes in the systems that govern the body's hormones and neurochemicals.

Experimentation

Belyayev decided to test his theory by domesticating red foxes; in particular the silver fox, a dark-colored mutation of the red fox. He placed a population of them under strong selection pressure for inherent tameness.[9] According to Trut:

The least domesticated foxes, those that flee from experimenters or bite when stroked or handled, are assigned to Class III. Foxes in Class II let themselves be petted and handled but show no emotionally friendly response to experimenters. Foxes in Class I are friendly toward experimenters, wagging their tails and whining. In the sixth generation bred for tameness we had to add an even higher-scoring category. Members of Class IE, the "domesticated elite", are eager to establish human contact, whimpering to attract attention and sniffing and licking experimenters like dogs. They start displaying this kind of behavior before they are one month old. By the tenth generation, 18 percent of fox pups were elite; by the 20th, the figure had reached 35 percent. Today elite foxes make up 70 to 80 percent of our experimentally selected population.[2]

Belyayev and Trut believed that selecting for tameness mimics the natural selection that must have occurred in the ancestral past of dogs, and, more than any other quality, must have determined how well an animal would adapt to life among humans.

Results

Russian scientists achieved a population of domesticated red foxes that are fundamentally different in temperament and behavior from their wild forebears. Some important changes in physiology and morphology became visible, such as mottled or spotted colored fur.[10] Some scientists believe that these changes obtained from selection for tameness are caused by lower adrenaline production in the new population,[11] causing physiological changes within relatively few generations yielding genetic combinations not present in the original species. This indicates that selection for tameness (e.g. did not flee) produces changes that are related to the emergence of other dog-like traits (e.g. raised tail, coming into heat every six months rather than annually). These seemingly unrelated changes are a result of pleiotropy.[1]p. 5

The project also bred the least-tameable foxes to study social behavior in canids. These foxes avoided human contact, as do their wild behavioral phenotypes.[12][3]

Similar research was carried out in Denmark with American minks.[13]

Current project status

Following the demise of the Soviet Union, the project ran into serious financial problems. In 2014, officials stated that the number of foxes was never reduced and is still stable at about 2,000.[14] As of August 2016, there are 270 tame vixens and 70 tame males on the farm.[15][3]

In another published study, a system of measuring fox behavior was described that is expected to be useful in QTL mapping to explore the genetic basis of tame and aggressive behavior in foxes.[16]

The sculpture "Dmitriy Belyaev and the Domesticated Fox" was built near Institute of Cytology and Genetics (Novosibirsk) the honor of the 100th anniversary of the birth of Dmitry Konstantinovich Belyaev. The tamed fox gives the scientist a paw and wags its tail. Konstantin Zinich, sculptor (Krasnoyarsk) says "The philosophy of touching a fox and a man is rapprochement, kindness, there is no aggression from the fox – it was wild, and he made it genetically domesticated."[17]

Morphology

Domesticated red foxes exhibit a variety of coat color mutations,[18] including red, cross, silver (black), platinum, and Georgian white, the lattermost being a color exclusive to the Russian breeding project.[2][3]

Ancient attempts

Archaeologists have discovered evidence of red fox breeding in the late Iron Age on Orkney, off the northern coast of Scotland. After the attack of the Vikings in Scotland around A.D. 800, the breeding is said to have stopped.[19]

See also

References
  1. Darwin, Charles (1859). "1". On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (1963 reprint ed.). Norwalk, Connecticut: Heritage Press. p. 470.
  2. Trut, Lyudmila (1999). "Early Canid Domestication: The Farm-Fox Experiment". American Scientist. 87 (2): 160. Bibcode:1999AmSci..87.....T. doi:10.1511/1999.2.160. JSTOR 27857815.
  3. Trut, Lyudmilla; Dugatkin, Lee Alan (23 March 2017). How to Tame a Fox (and Build a Dog): Visionary Scientists and a Siberian Tale of Jump-Started Evolution (1st ed.). Chicago: University Of Chicago Press. p. 240. ISBN 978-0226444185.
  4. "Domestication of foxes and problems of modern animal breeding". www.bionet.nsc.ru. Retrieved 5 July 2016.
  5. "Why domesticated foxes are genetically fascinating (and terrible pets)". pbs.org. 2017-03-31.
  6. Lord, Kathryn A.; Larson, Greger; Coppinger, Raymond P.; Karlsson, Elinor K. (2020). "The History of Farm Foxes Undermines the Animal Domestication Syndrome". Trends in Ecology & Evolution. 35 (2): 125–136. doi:10.1016/j.tree.2019.10.011. PMID 31810775.
  7. Ratliff, Evan (March 2011). "Animal Domestication: Taming the Wild". National Geographic. p. 2. Archived from the original on 22 November 2015.
  8. "Why domesticated foxes are genetically fascinating (and terrible pets)". PBS NewsHour. 2017-03-31. Retrieved 2018-10-18.
  9. Adams, Jill U. (2008). "Genetics of Dog Breeding". Nature Education. 1 (1). Archived from the original on 19 October 2008.
  10. Lantzas, Katie (2018). "Gone to the dogs". Distillations. 4 (2): 44–47. Retrieved November 26, 2018.
  11. Goldman, Jason G. (September 6, 2010). "Man's new best friend? A forgotten Russian experiment in fox domestication". Scientific American Guest Blog. Retrieved 26 November 2018.
  12. Trut, Lyudmila N.; Oskina, Irina N.; Kharlamova, Anastasiya V. (2012). "Experimental Studies of Early Canid Domestication". In Ostrander, Elaine A.; Ruvinsky, Anatoly (eds.). Genetics of the Dog (2nd ed.). CAB International. pp. 12–37. ISBN 9781845939410. Retrieved 12 January 2016.
  13. Price, Edward (2008). Principles and Applications of Domestic Animal Behavior. Cambridge University Press. p. 229. ISBN 9781780640556. Retrieved 7 January 2016.
  14. "Конец Эксперимента. Ученые Уничтожают Ручных Лисиц и Норок" [The End of an Experiment: Scientists Kill Domesticated Foxes and Minks]. Smartnews.ru (in Russian).
  15. "A Soviet scientist created the only tame foxes in the world". BBBC Earth. 13 September 2016.
  16. Kukekova, Anna V.; Trut, L. N.; et al. (2007). "Measurement of Segregating Behaviors in Experimental Silver Fox Pedigrees". Behavior Genetics. 38 (2): 185–94. doi:10.1007/s10519-007-9180-1. PMC 2374754. PMID 18030612.
  17. "В Новосибирске открыли памятник ученому с доброй лисой | ИЦиГ". www.bionet.nsc.ru.
  18. http://livingwithfoxes.weebly.com/red-fox-colour-mutations.html Archived 2017-11-07 at the Wayback Machine Red Fox Colour Mutations
  19. An online note is available via WayBack Machine: Original references is: Winckelmann-Pelz-Report. Nr. 1814 vom 8th of Dezember, 2006 (German), based on the following sources:
    • Daily Record and Scotland Mail, 27.th of November, 2006
    • eMail service of USA Fur Commission
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