27. Shared Cultigens: From New into Old (World)
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27 Shared Cultigens From New into Old (World) Is there no respect of place . . . nor time in you? —William Shakespeare, Twelfth Night, 2. 3. (80), 1601 In the previous chapter, we saw that there are cases—open and shut, in the instance of the chicken—to be made for the pre-­ Columbian presence of certain domesticated animal species in the “wrong” hemisphere, and that, being genetic entities, not man-­ made inventions, demonstration of any such presence suggests, more than strongly, human carriage. The present chapter and the following two look at cultivated plants in similar light and find them to be definitive “smoking guns” signaling transoceanic transfer and thus opportunity for cultural diffusion. The Evidentiary Value of Cultivated Plants Although no proof is absolute outside of mathematics, as noted in the previous chapter bio­ logi­ cal indications are among the clearest and least equivocal that imply early and important interhemispheric interactions. Unlike physical materials, bio­ logi­ cal ones have received considerable attention in the context of transoceanic-­ contact investigations. It is widely recognized that research on shared cultivated plants may go far toward finally settling the argument over whether or not influential pre-­ Norse transoceanic exchanges really occurred. In chapter 7, we took note of the supposed absence of interhemispherically shared cultivated plants. This was a notion given momentum by the influential Swiss botanist Alphonse de Candolle, who in 1883 averred, “In the history of cultivated plants, I have noticed no trace of communication between the­ peoples of the old and new worlds before the discovery of America by Columbus .”1 This view, also loudly touted (with some grudging qualifications) by the mid-­ twentieth-­ century Harvard plant taxonomist Elmer Drew Merrill and oft repeated ever since, has been a significant reason for resistance to the notion Shared Cultigens / 299 of early transoceanic contacts. The Ameri­ can anthropologist and specialist in culture-­ trait distributions Harold E. Driver wrote in 1973, My conclusion is that not a single case for pre-­ Columbian diffusion of a domesticated plant across the Pacific from the Old World to the New is tenable today. . . . [Other than the bottlegourd, which was probably independently domesticated , a]ll other pre-­ Columbian domesticated species except the sweet potato were confined to only one hemisphere. The very rapid and ubiquitous exchange of domesticated plants between the hemispheres suggests that if there had been even a modest amount of communication by sea before that date more plants would have been exchanged than the record shows.2 An ostensible dearth of archaeo­ logi­ cal specimens of interhemispherically transferred species of cultivated plants is not surprising in view of plants’ high degree of perishability under most conditions. For example, in light of a total lack of finds or depictions of tomatoes in Ameri­ can archaeology (the plant was first recorded by Europeans in 1519), we could not prove its pre-­Columbian presence in the hemisphere (or the world) were it not for nonarchaeo­ logi­ cal botanical evidence. Despite perishability problems, indications of pre-­ Columbian interhemispheric sharings of cultivated plants have proliferated over the years, especially during the 1990s and 2000s, and Driver’s alleged blank record has been much filled in. Indeed, as long ago as 1962 the Ameri­ can geographers Philip L. Wagner and Marvin W. Mikesell wrote, “The most convincing evidence of intercourse between the New World and the Old before Columbus . . . is undoubtedly the presence of certain domesticated plants (e.g., the sweet potato) on both sides of the Pacific at the time of first European contact.”3 The modern study of human domesticates in the transoceanic context was pioneered especially by George F. Carter in the 1950s and 1960s, following earlier leads on the part of scholars such as the early twentieth-­ century US government botanist O. F. Cook and Carter’s professor, the geographer Carl O. Sauer.4 As these scientists pointed out, although humans may affect the evolutions of plants and animals, most notably their domesticates, none of these species can be “invented,” or selected into existence as cultigens or as domesticated animals, other than where an appropriate wild ancestor exists (sometimes, more than one ancestral species has been involved, producing hybrid domesticates). Although many wild plant and some terrestrial wild animal species are shared between the hemispheres in the Arctic and subarctic, the same is not true in the Tropics and subtropics. In fact, except for strand (shoreline) plants, although sharing some genera the tropical higher-­ plant wild floras of the two hemispheres have almost no species...