1. Reply to Smith: On distinguishing between models, hypotheses, and theoretical frameworks.

    PNAS 111(28):E2830 (2014) PMID 25157385 PMCID PMC4104893

  2. Reply to Zeder: Maintaining a diverse scientific toolkit is not an act of faith.

    PNAS 111(28):E2828 (2014) PMID 25157384 PMCID PMC4104875

  3. Particularism and the retreat from theory in the archaeology of agricultural origins.

    PNAS 111(17):6171 (2014) PMID 24753601 PMCID PMC4035987

    The introduction of new analytic methods and expansion of research into previously untapped regions have greatly increased the scale and resolution of data relevant to the origins of agriculture (OA). As a result, the recognition of varied historical pathways to agriculture and the continuum of ...
  4. Current perspectives and the future of domestication studies.

    PNAS 111(17):6139 (2014) PMID 24757054 PMCID PMC4035915

    It is difficult to overstate the cultural and biological impacts that the domestication of plants and animals has had on our species. Fundamental questions regarding where, when, and how many times domestication took place have been of primary interest within a wide range of academic disciplines...
  5. Preceramic maize from Paredones and Huaca Prieta, Peru.

    PNAS 109(5):1755 (2012) PMID 22307642 PMCID PMC3277113

    Maize (Zea mays ssp. mays) is among the world's most important and ancient domesticated crops. Although the chronology of its domestication and initial dispersals out of Mexico into Central and South America has become more clear due to molecular and multiproxy archaeobotanical research, importa...
  6. Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium).

    PNAS 108(2):486 (2011) PMID 21187393 PMCID PMC3021051

    The nature and causes of the disappearance of Neanderthals and their apparent replacement by modern humans are subjects of considerable debate. Many researchers have proposed biologically or technologically mediated dietary differences between the two groups as one of the fundamental causes of N...
  7. Human behavioral ecology, phenotypic (developmental) plasticity, and agricultural origins: insights from the emerging evolutionary synthesis.

    Current Anthropology 50(5):615 (2009) PMID 20642147

    The fields of human behavioral ecology (HBE) and evolutionary developmental biology (evo-devo) both stand to make significant contributions to our understanding of agricultural origins. These two approaches share a concern with phenotypic-plasticity and its evolutionary significance. HBE conside...
  8. The cultural and chronological context of early Holocene maize and squash domestication in the Central Balsas River Valley, Mexico.

    PNAS 106(13):5014 (2009) PMID 19307573 PMCID PMC2664064

    Molecular evidence indicates that the wild ancestor of maize is presently native to the seasonally dry tropical forest of the Central Balsas watershed in southwestern Mexico. We report here on archaeological investigations in a region of the Central Balsas located near the Iguala Valley in Guerr...
  9. Starch grain and phytolith evidence for early ninth millennium B.P. maize from the Central Balsas River Valley, Mexico.

    PNAS 106(13):5019 (2009) PMID 19307570 PMCID PMC2664021

    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 dat...
  10. Starch grains on human teeth reveal early broad crop diet in northern Peru.

    PNAS 105(50):19622 (2008) PMID 19066222 PMCID PMC2604935

    Previous research indicates that the Nanchoc Valley in northern Peru was an important locus of early and middle Holocene human settlement, and that between 9200 and 5500 (14)C yr B.P. the valley inhabitants adopted major crop plants such as squash (Cucurbita moschata), peanuts (Arachis sp.), and...
  11. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths.

    PNAS 104(45):17608 (2007) PMID 17978176 PMCID PMC2077075

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoa...
  12. Microfossil evidence for pre-Columbian maize dispersals in the neotropics from San Andres, Tabasco, Mexico.

    PNAS 104(16):6870 (2007) PMID 17426147 PMCID PMC1871877

    The history of maize (Zea mays L.) is one of the most debated topics in New World archaeology. Molecular and genetic studies indicate that maize domestication took place in tropical southwest Mexico. Although archaeological evidence for the evolution of maize from its wild ancestor teosinte has ...
  13. Starch fossils and the domestication and dispersal of chili peppers (Capsicum spp. L.) in the Americas.

    Science 315(5814):986 (2007) PMID 17303753

    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 domest...
  14. Early maize agriculture and interzonal interaction in southern Peru.

    Nature 440(7080):76 (2006) PMID 16511492

    Over the past decade, increasing attention to the recovery and identification of plant microfossil remains from archaeological sites located in lowland South America has significantly increased knowledge of pre-Columbian plant domestication and crop plant dispersals in tropical forests and other...
  15. Paleontology. Dinosaurs dined on grass.

    Science 310(5751):1126 (2005) PMID 16293745

  16. Processing of wild cereal grains in the Upper Palaeolithic revealed by starch grain analysis.

    Nature 430(7000):670 (2004) PMID 15295598

    Barley (Hordeum vulgare 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 w...
  17. Phytolith evidence for early Holocene Cucurbita domestication in southwest Ecuador.

    Science 299(5609):1054 (2003) PMID 12586940

    Cucurbita (squash and gourd) phytoliths recovered from two early Holocene archaeological sites in southwestern Ecuador and directly dated to 10,130 to 9320 carbon-14 years before the present (about 12,000 to 10,000 calendar years ago) are identified as derived from domesticated plants because th...
  18. Paleoecological and archaeological implications of a late Pleistocene/Early holocene record of vegetation and climate from the pacific coastal plain of panama

    Quaternary Research 59(1):79 (2003)

    A phytolith record from Monte Oscuro, a crater lake located 10 m above sea level on the Pacific coastal plain of Panama, shows that during the Late Pleistocene the lake bed was dry and savanna-like vegetation expanded at the expense of tropical deciduous forest, the modern potential vegetat...
  19. Terminal Pleistocene/Early Holocene human adaptation in coastal Ecuador: the Las Vegas evidence

    Quaternary International 109:23 (2003)

    Preceramic sites located on the Santa Elena Peninsula in southwestern Ecuador and occupied in the Terminal Pleistocene and during the Early Holocene (10,800–6600 BP) have produced evidence of a durable Las Vegas adaptation focused on marine, estuarine and terrestrial resources. The La...
  20. Evidence for the control of phytolith formation in Cucurbita fruits by the hard rind (Hr) genetic locus: Archaeological and ecological implications.

    PNAS 99(16):10923 (2002) PMID 12149443 PMCID PMC125074

    Many angiosperms, both monocotyledons and dicotyledons, heavily impregnate their vegetative and reproductive organs with solid particles of silicon dioxide (SiO(2)) known as opaline phytoliths. The underlying mechanisms accounting for the formation of phytoliths in plants are poorly understood, ...