As with pigs, Vavilov speculated that chickens might have been domesticated independently in the Near East and in southeast Asia. That seems wide of the mark. The best evidence to date suggests that red jungle fowl (Gallus gallus) in a small area of Thailand were the ancestors of all modern chickens, [1] with a bit of input from the grey junglefowl (G. sonneratii) thrown in for good measure, and a yellow skin.
A bigger flap concerns the chickens of South America, and in particular the question whether they arrived from east or west. The conventional view is that the chicken is a post-Columbian bird in the Americas. Some scholars, however, argued that old breeds of Chile — for example the Araucana, with their blue-green eggs, and the Passion Fowl — spring from Asian birds that arrived across the Pacific from Polynesia.
Once again, scientists turned to DNA for answers. They found that native Chilean birds had DNA that put them firmly with the birds of Europe and India. Furthermore, they said that an “apparently pre-Columbian” specimen from Chile and pre-European specimens from Polynesia shared the same background with European and Indian birds.
The proponents of the pre-Columbian chickens fought back. “We present additional data supporting the interpretation of Storey et al. showing that evidence for pre-Columbian chickens at the site of El Arenal, Chile, is secure.”
To which the first bunch replied that the pre-Columbians “concede that there is no direct genetic support for Polynesian–South American contact. However, they claim that linguistic, archaeological, and ethnohistoric evidence supports Polynesia as the most likely source of the El Arenal-1 chickens. We disagree on two grounds.” [2]
It is clear, however, that some chickens from Easter Island are not European, share their ancestry with chickens “from Indonesia, Japan, and China and may represent a genetic signature of an early Polynesian dispersal”.
Science marches forward.
Notes:
- Not just those of 1868, shown in the photo, found by Luigi. [↩]
- The details of those grounds, alas, are hidden to casual readers behind a paywall. [↩]
