Monophyletic vs. polyphyletic origin of the crops on which agriculture was founded in the Near East

The following comparisons between crops and their closely related wild relatives provide clues for discriminating between monophyletic and polyphyletic origins under domestication: (i) Presence or absence of patterns indicative of founder effects in the cultivated genepool, compared to the amount of variation present in its wild progenitor. (ii) Uniformity or lack of uniformity (within a crop) in genes governing principal domestication traits (traits that were automatically selected for once the wild progenitor was introduced into cultivation). (iii) Species diversity: The number of closely related (congeneric) wild species with similar potential for domestication, native to the area under consideration; and how many of them entered cultivation. The present paper evaluates the information available on the eight crops that founded Neolithic agriculture in the Near East; and arrives at the conclusion that emmer wheat Triticum turgidum L. subsp. dicoccum Schubler, einkorn wheat T. monococcum L., pea Pisum sativum L., and lentil Lens culinaris Medik. were very likely taken into cultivation only once or - at most - a very few times. Also chickpea Cicer arietinum L., bitter vetch Vicia ervilia (L.) Willd., and flax Linum usitatissimum L. seem to have been domesticated in a similar way, but the evidence concerning them is much scarcer. Only for barley Hordeum vulgare L, are there indications that it has been domesticated more than once - but again only a very few times.