Dating archaeobotanical treasure troves from Armenia and Peru

The arrival of a new issue of Antiquity is always a welcomed event. The issue that arrived in my mail box this week a particular trove of treasures of an archaeobotanical sort. Not so much for archaeobotanical reports as such (the only such is the study by Willcox and  Strodeur on the details of Jerf el Ahmar), but for tantalizing new information of sites that have exceptional plant assemblages, or that one expects will in the future, like the Han era Pompeii, Sanyanzhuang (blogged below). Two sites, which are well-known for exceptional preservation are the Areni-1 cave complex in Aremenia (Areshian et al in Antiquity), left, and Huaca Prieta mound in coastal peru, below right (Dillehay et al.). 

     Areni made the news a couple of years ago for its early leather footwear, from ca. 3500 BC (Pinhasi et al in PLOSone), but it also has dessicated plant remains of many sorts: emmer and free-threshing wheat and barley, of course, but also lentil, grasspea, grapes, plums, walnuts, almonds and pears. How many of these fruit and nuts represent species that were available wild in the region, were under cultivation or introduced as cultivars still needs to be clarified. The site has produced features indicating on-site wine production, so presumably grapes were cultivated, from at least, from around 4000 BC. 4000 BC is associated with the earliest material reported so far, but the site still has much to yield to excavation, presumably including earlier material. Late samples from the past 2000 years include cotton and textiles.

     Huaca Prieta also boasts exceptional archaeobotanical preservation, and with a long sequence it provides information that suggests the chronology of cultivar introductions in this region. Few plants are likely to be native here and so their introductions point earlier cultivation and domestication elsewhere. This includes Cucurbita sqaush, avocado and lima bean at 7000-5500 BC, and thereafter the appearance of chillis and bottlegourds. Cotton cultivation was established around 4800 BC, and after 4500 BC maize was added to the repertoire. This is some of the best dated and documented early maize in South America, detailed of which were published earlier this year (see previous blog). Peanut, sweet potato and quinoa also come from later levels. Full details are not yet published but some summary can be found in the on-line supplement. This site has also produced coca leaves, indicating the long traditions of chewing this drug plant. Dillehay and colleagues reported the earliest for use of this drug, back to ca. 6000 BC, from elsewhere in northern Peru about a year and half ago, also in Antiquity. Intriguingly this drug plant, plausibly from across the Andes, appeared to already have domestication features at this date.

Locating American bean domestications

A couple of recent papers of the UC Davis crops sciences group, continue the research tradition of Paul Gepts in providing further refinements in out undrerstanding of Phaeseolus vulgaris domestications, especially in terms of locating these two domestications and identifying closed related wild popualations.

Kwak and Gepts published in Theoretical & Applied Genetics 118 [March 2009] an open access paper on a phylogenetic and population structure analysis on wild and domesticated beans, reinforcing earlier inferences of separate Mesoamerica and SOuth American origins.

Further details on the Mesomaerican wild populations, their relationships and distributions, can be found in another paper by Kwak, Kami and Gepts (2009) The Putative Mesoamerican Domestication Center of Phaseolus vulgaris Is Located in the Lerma-Santiago Basin of Mexico, Crop Science 49: 554-563. This study concludes that Mexican beans did not originate in the Rio Balsas valley favoured for maize origins--and supported by recent archaeobotany work, but elsewhere in Southwest Mexico. This was on the News feeds of the Crop Society of America last week.