In a comment to the previous post, Alan Reed Bishop brings up an issue closely related to the recent evidence for early maize cultivation in Chaco Canyon: the introduction of domesticated turkeys to the Southwest. A recent study of archaeological turkey remains found that the majority of the turkeys found in Southwestern archaeological sites are genetically distinct from both the local subspecies of wild turkey and the subspecies found in Mexico that was domesticated there and is ancestral to the modern domestic turkey. Instead, the Southwestern domestic turkeys were closest genetically to two subspecies of wild turkey found to the east and southeast, in the southern Plains and the eastern US. This strongly implies that turkeys were domesticated somewhere to the east and then introduced to the Southwest as domestic animals, presumably through long-distance trade contacts.
The earliest remains used in that study were coprolites from Turkey Pen Cave in Grand Gulch, Utah, and date to the Basketmaker II period. Some of these coprolites were also directly dated by AMS; the earliest had a 95% confidence interval of AD 20 to 200. Like the bones from other sites analyzed in the same study, the Turkey Pen Cave coprolites indicated that most of the turkeys kept there belonged to the domesticated lineage, apparently non-local, that showed strong similarities to wild subspecies further east. In addition, an earlier study of Basketmaker II subsistence in the Cedar Mesa/Grand Gulch area, using a variety of lines of evidence including coprolites, found that corn agriculture was already as central to the Basketmaker II subsistence system as it would be in later Pueblo times. The presence of domesticated turkeys as well as corn agriculture as well-established aspects of Basketmaker II society seems to imply that both were introduced earlier, perhaps in the Archaic period, and the accumulating evidence for Archaic maize throughout the Southwest supports this supposition. Less study has been done of turkeys, however, and while the DNA study refers to alleged Archaic turkey remains from the Southwest, the references are to obscure sources that I have not been able to track down.
Regardless of when domesticated turkeys were first introduced to the Southwest, they presumably were not introduced along with maize. Turkeys seem to have been introduced from the east, while maize definitely came from the south. It is possible that both came from northeastern Mexico, where one of the wild turkey subspecies similar to the Southwestern type is found, but there is basically no evidence for direct contact between that area and the Southwest, and the earliest evidence for maize there apparently dates to approximately the same period as the earliest Southwestern maize, suggesting that agriculture was not introduced to this area early enough to make it the vector for transmission to the Southwest. It is much more likely that maize was introduced through western and/or northern Mexico, areas with extensive evidence for contact with the Southwest throughout prehistory. So it seems quite clear that the introduction of turkeys and corn were separate events, but it seems equally clear that both were in fact introduced from elsewhere, probably during the Late Archaic, and it is striking that they seem to be present together from quite early on, at least on the Colorado Plateau. (Turkeys are conspicuously absent from early agricultural sites in southern Arizona, which is another piece of evidence suggesting that they were not introduced from the south.) I’m not really sure what the upshot of all this is, but it’s certainly interesting stuff.
Matson, R., & Chisholm, B. (1991). Basketmaker II Subsistence: Carbon Isotopes and Other Dietary Indicators from Cedar Mesa, Utah American Antiquity, 56 (3) DOI: 10.2307/280894
Speller, C., Kemp, B., Wyatt, S., Monroe, C., Lipe, W., Arndt, U., & Yang, D. (2010). Ancient mitochondrial DNA analysis reveals complexity of indigenous North American turkey domestication Proceedings of the National Academy of Sciences, 107 (7), 2807-2812 DOI: 10.1073/pnas.0909724107