Was The Turkey Domesticated Twice?

A paper in PNAS looks at that question. The paper, Ancient mitochondrial DNA analysis reveals complexity of indigenous North American turkey domestication looks at the motchondrial DNA of 200 turkey samples (including 149 bones and 39 coprolites from 38 archaeologica sites). Also included were 276 domestic and wild turkey sequences from GenBank.

Twelve haplotypes falling into three haplogroups were discovered. The first haplogroup contained most of the archaeological sample. The second group contained the rest of the archaeological sample (about 14 % of the total archaeological sample). The third group contained all of the modern sample as well as museum specimens of wild South Mexican turkey. The authors of the paper interpret the groupings as follows:

The presence of a distinct “Mesoamerican” clade (H3), including both commercially raised birds and historic wild M. g. gallopavo, is consistent with our historical understanding of south-central Mexico as the domestication center for the Mesoamerican turkey, with the South Mexican wild turkey as the progenitor subspecies. This result is also consistent with our historical understanding that today’s commercial birds originate from southern Mexico (4). The overall genetic uniformity of the Mesoamerican clade may be due to the limited mtDNA data available for wild M. g. gallopavo and the current lack of mtDNA data for the many modern domestic turkey breeds worldwide. To gain a more accurate view of the timing, specific geographic origin, and history of modern domestic turkey breeds, a more thorough genetic study must be conducted incorporating securely dated Mesoamerican archaeological samples and a wide range of modern turkey varieties (including the indigenous breeds of Mexico). Nevertheless, the current distinction between the H3 Mesoamerican clade and the H1 and H2 Southwest clades, does suggest that the turkeys exploited in the Southwest have a separate history and origin from Mesoamerican and modern domestic turkeys.

Okay, so, if there two centers of domestication and South Mexican wild turkey is ancestral stock for the Mesoamerican turkey, where does the Southwestern turkey come from? There are two possibilities – M. g. silvestris or M. g. intermedia and the data presented do not allow one to choose.

The authors go on to point out that:

The ancient DNA and archaeological evidence collected in this study reveals a wide range of past human-animal interactions within the Southwest United States, ranging from the hunting and/or capture of local wild turkeys, to the intensive husbandry and breeding of an imported domestic turkey lineage. Moreover, the DNA data indicate this Southwest domestic turkey lineage (H1) was maintained and propagated for well over a millennium, despite significant shifts in the geographic distribution and settlement patterns of Southwestern farming populations. This long history of turkey use undoubtedly reflects the economic and symbolic importance of domestic turkey for the Ancestral Puebloans, and other precontact Southwestern cultures.