The irony of Soviet silver fox domestication
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| Left: wild silver fox (grr!) Right: domesticated silver fox (aww!) |
Biologist Dmitri Belyaev (1917-1985) was dismissed from his post in a Moscow fur breeding laboratory in 1948 for his insistence that Darwinian artificial selection could produce rapid evolutionary change. During the Khrushchev ideological thaw, he was appointed head of a genetics institute in southern Siberia, safely away from the establishment.
From 1959 until his death, he was responsible for a spectacular experiment. Silver foxes were highly prized for their pelts, but they did not fare well in captivity. The obvious solution: breed them for docility. Belyaev patiently selected the foxes that were the least agitated around humans, and after only 40 generations had basically recapitulated the domestication of the wolf into the dog.
The Wild foxes had pointed ears, strong jaws, long tails, and silver coats.
The domesticated foxes had floppy ears, overbites, short tails which they wagged -- and, ironically, piebald coats which were basically useless to furriers!
These are all characteristics which, along with playfulness and trust of humans, they share with infant feral foxes. The wild ones grow out of these traits, but the domesticated ones were bred to retain them. (Evolutionary change to retain childlike characteristics is called neoteny, and it's an important part of hominid evolution: humans look much more like baby apes and chimpanzees than we do the adult primates.)
There's a sad coda to this tale: the breeding was continued after Belyaev's death, and is still ongoing, but the domesticated fox population is severely reduced due to post-Soviet economic troubles; many of them were sold as pets.
Bibliography:
Belyaev, D. K., Ruvinsky, A.o., Trut, L.N. 1981. Inherited activation-inactivation of the star gene in foxes. The Journal of Heredity 72:264–274.
Trut, L.N. 1999) Early Canid Domestication: The Farm-Fox Experiment. American Scientist 87(2): 160
If you want to read more, here is a great article written by the scientist who inherited the experiment from Belyaev.
Word clouds of the human genome: most and least frequent words
I work in genomics, so I thought it was time to geek out this week.
The words are taken from the reference human genome annotations in UniProt; I wanted to use the same font as the UniProt logo, but I couldn't find it, so I went with a similar Bauhaus-style font that had a serendipitous name (and was free): Monoglyceride, by Tepid Monkey Fonts.
Instead of limiting the cloud to the presently confirmed 20,272 genes, I used all 69,049 annotations (which still, BTW, covers less than 7% of the genome). You can see both data sets here; the difference between them is not dramatic, except that the unreviewed set contains the words "fragment" over 1000 times more often.
The annotation contains 505,128 "words" (any combination of contiguous letters is considered a word, punctuation and numbers are removed), and 14,689 unique words. The frequency is very unequally distributed: the top two words, "protein" and "fragment", take up almost 16% of the total words, while words that appear only once (we call them "hapax legomena" in text mining) are 40% of the number of unique words. (I made some histograms, but they're not that interesting to look at; maybe I was just unsuccessful at figuring out a way to communicate the distribution clearly.)
Among the hapaxes are the following words, which I picked out for no other reason than they caught my eye as incongruous in some way:
My favourite one is "haponin." Now when someone asks me, "Hey, man, what's haponin?" I can respond, "It's a protein similar to Human Leukemia Differentiation Factor but without nuclease activity."
