Mesoamerica
The Americas, and especially Mesoamerica, have been another world region in which recent scholarship has applied linguistic evidence to the study of early agricultural history. In contrast to the wide approach taken in Oceanic history, the linguistic study of early American agriculture has not yet given major attention to the kinds of evidence that are inherently indicative of cultivation, namely the verbs and nouns that specifically connote the carrying out of cultivation.
The American work has concentrated on the histories of the terms for individual crops.[115] That approach is problematic because across many parts of Mesoamerica the wild progenitors of the cultivated plants, such as squash and beans, grew in the same lands in which people have cultivated those plants for thousands of years. How can we be sure that theAgricultural origins: what linguistic evidence reveals reconstruction of old terms for any particular crop implies cultivation rather than the collection of the wild forms of the crop?
Cecil Brown, a major recent contributor to this field of study, confronts this problem by applying the criterion of cultural salience in studying the lexical histories of three major American crops, maize, squash, and beans. He makes use of the linguistic finding that the words for items of major cultural importance tend to be retained in use over very long spans of time and to be replaced by new words only rarely.[116]
What this approach probably most often brings to light is the historical period in which a crop took on particular cultural salience, that is to say, the period when it became a staple of the diet, rather than the earliest period in which it might have been grown. A crop that gains high cultural salience is most often one that has a history of previous cultivation.
So the high salience of a crop tends also to mean that the process of domestication of the plant has already been underway. Its position as a mainstay in the diet means that farmers are selecting, consciously or unconsciously, for plant characteristics that yield more product or require less labour and thus make the plant gradually more and more different from its wild ancestor.But this kind of evidence does not resolve the question of when the practices of cultivation themselves began. Reconstructing ancient verbs and nouns for the activities of cultivation, which does provide diagnostic information, remains a task still to be systematically undertaken for the Americas. In addition, the studies so far have left aside a great many important crops domesticated by Native Americans: the pumpkin, perhaps first cultivated as early as 8000 bce in Mexico; the potato, a primary crop of the separate Andean centre of agricultural innovation; sweet potatoes, peanuts, cassava, and yams from the Orinoco and Amazon lowland centre; and such crops as sunflowers, domesticated 3000-4000 years ago in what is today the southeastern United States.