Questions that still surround the origin and early dispersals of maize (Zea mays L.) result in large part from the absence of information on its early history from the Balsas River Valley of tropical southwestern Mexico, where its wild ancestor is native. We report starch grain and phytolith data from the Xihuatoxtla shelter, located in the Central Balsas Valley, that indicate that maize was present by 8,700 calendrical years ago (cal. B.P.). Phytolith data also indicate an early preceramic presence of a domesticated species of squash, possibly Cucurbita argyrosperma. The starch and phytolith data also allow an evaluation of current hypotheses about how early maize was used, and provide evidence as to the tempo and timing of human selection pressure on 2 major domestication genes in Zea and Cucurbita. Our data confirm an early Holocene chronology for maize domestication that has been previously indicated by archaeological and paleoecological phytolith, starch grain, and pollen data from south of Mexico, and reshift the focus back to an origin in the seasonal tropical forest rather than in the semiarid highlands.early Holocene ͉ maize domestication ͉ phytoliths ͉ starch grains

* These authors contributed equally to this work.Barley (Hordeum vulgäre L.) and wheat {Triticum monococcum L. and Triticum turgidum L.) were among the principal 'founder crops' of southwest Asian agriculture\ Two issues that were central to the cultural transition from foraging to food production are poorly understood. They are the dates at which human groups began to routinely exploit wild varieties of wheat and barley, and when foragers first utilized technologies to pound and grind the hard, fibrous seeds of these and other plants to turn them into easily digestible foodstuffs. Here we report the earliest direct evidence for human processing of grass seeds, including barley and possibly wheat, in the form of starch grains recovered from a ground stone artefact from the Upper Palaeolithic site of Ohalo II in Israel. Associated evidence for an oven-like hearth was also found at this site, suggesting that dough made from grain flour was baked. Our data indicate that routine processing of a selected group of wild cereals, combined with effective methods of cooking ground seeds, were practiced at least 12,000 years before their domestication in southwest Asia.Ohalo II is located on the southwestern shore of the Sea of Galilee at an elevation of 212 m below sea level. In most years the site is submerged in 2-3 m of water. Ohalo II was exposed in 1989 and 1999, following a dramatic drop in the water level of the lake; today the site covers an area of about 2,000 m^. Three seasons of excavations took place during each of the low-level events before it was submerged again. The work revealed the remains of a camp, including six brush huts built from branches and leaves, hearths and a human grave^'. All the features were well-preserved, having been found in situ in the waterlogged sediments.

Chili peppers ( Capsicum spp.) are widely cultivated food plants that arose in the Americas and are now incorporated into cuisines worldwide. Here, we report a genus-specific starch morphotype that provides a means to identify chili peppers from archaeological contexts and trace both their domestication and dispersal. These starch microfossils have been found at seven sites dating from 6000 years before present to European contact and ranging from the Bahamas to southern Peru. The starch grain assemblages demonstrate that maize and chilies occurred together as an ancient and widespread Neotropical plant food complex that predates pottery in some regions.