|Pre-European Pacific Migration of Plants
Sam Cox December 2000
True to the centuries-old belief that the world moves by the hand of the Europeans, so it goes that the exchange of plant germplasm, or anything else for that matter, across the Pacific Ocean from South America to China, or vice versa, was and is thought to be nonexistant before the age of European naval exploration. The evidence of this is by no means overwhelming, and in fact, evidence for just the opposite is more compelling. It is very likely that people were moving across the Pacific Ocean prior even to European knowledge of the Western hemishpere.
Histories of several crop species support this view. The coconut palm is an interesting plant in that it is probably native to Southeast Asia, but was found on the western coast of Central America in what is now Panama in 1519 by a Spanish explorer (Pickersgill, 1997). How did coconut palm get to Central America from Southeast Asia? Plate techtonic patterns show that the distance between Asia and the Americas is decreasing, not increasing, so the two continents were never connected, but were in fact on opposite sides of the prehistoric landmass Pangea. Some have argued that coconuts, which float well and are durable for weeks at sea (Moore, et al. 1995), could have been carried along on anomolous easterly currents and made landfall in the Americas. Others argue that coconut palm originated in Central America, and followed predominantly westerly currents to the Pacific Islands (Hartmann1, et al.1986). Either is possible, but a multitude of other crops which also appear on both sides of the Pacific could never have survived that long at sea to produce viable plants upon landfall.
Pickersgill (1997) quotes 94 genera as being found in both South America and Australasia. Another Asian native, the bottle gourd, could conceivably float on water and move across the ocean by island-hopping, much like the coconut, but given other lines of evidence, human transport of plant germplasm seems more likely.
Corn has recieved some attention after researchers claimed to have identified corn in stone carvings inside the Somnathpur Temple in southern India. The temples were dated to 12th or 13th century A.D., and contained statues of servants to a god, 65 of whom are holding what appears to be corn. The width/thickness ratio of kernals of the sculpted corn overlap with ancient cultivar W/T ratios. The curved nature of the cob in the statues mimics the traditional First Fruits Harvest, whereby unripe wet corn is allowed to dry before offering, causing it to bend. Hindu text speaks of Vishnu as associated with golden offerings, and since corn is golden in color, it could well be seen as important in Hindu ceremonies. The fact that the sculptured corn is sometimes fully shucked and other times partially shucked lends support to the idea that it represents corn and not some other fruit with a rough skin, else the fruits would all be uniform. Some of the sculptures even appear to have silk on the cobs. Johannessen and Parker (1989) argue that this proves corn was present in Asia prior to European transport of the crop.
Payak and Sachan (1993) are bitterly opposed to this idea, and refute the evidence, although not convincingly. A detailed critique of their argements is in order. Payak and Sachan cite a 1932 government archaeological report of the Somnathpur Temple which states the statues are carrying a "fruit". They argue that if the sculpted pieces represented corn, the surveyors would have noted that, instead of referring to it generally as fruit. Only a poor researcher would use another's conclusion, or in this case, a lack of conclusion, as definitve proof. It is likely that the early surveyors were skeptical of the sculptures resemblance to corn, so they merely called it fruit to avoid any controversy, or to defer the exact identification to others. It is significant that these surveyors were archaeologists, not botanists.
They also say that a professor at an Indian University said the sculptures represented Muktaphala, "a fruit made of pearls". If so, it is curious that on some of the pearl fruits, there are smooth areas. Why don't the pearls cover the entire fruit? How can Payak and Sachan be sure that Muktaphala was not the name of maize given by native Indians? Indeed they also argue that since there is no name for maize among ancient people it did not exist, but here is the name Muktaphala, which means pearl fruit, and is associated with sculptures that look just like corn, according to an academic researcher. They argue that Muktaphala is an imaginary fruit, which is a nice convenient way to dismiss this term and claim that no name for maize existed then, even though it seems clear that Muktaphala means maize.
Another poor argument made by Payak and Sachan is that allometric analysis cannot be carried out on hand-crafted sculptures because of individual variation. According to Johannessen and Parker, the variation in sculpted corn kernals W/T ratios was actually less than the W/T ratio variation in actual maize kernals! Variation is to be expected in biological samples of any type, thus, allometric analysis is never perfect. But when the variation of the sculpted kernals is less than the actual biological material, how could anyone conclude the variation of the sculptures is too high?
In short, Payak and Sachan present multiple arguments that are not backed up by any quantitative data, but are merely nonsensical opinions. One wonders what their motive is, when it is clear that corn, or some knowledge of corn, was present in India by 1300 AD.
Sweet potato is native to South America, but was found cultivated throughout the Pacific islands by early European explorers (Hartmann 2, et al. 1988). A sweet potato, being much less durable than coconut, could not have reached the islands by means other than human transport. It is of no coincidence that the South Pacific is home to the great seafaring Polynesian people. Polynesians were sailing far and wide in the South Pacific long before the Europeans. Their culture revolved around it, as in the myth of Ru and Hina, two ancestral Polynesians who sailed the seas and discovered new lands (Pape-au, 1824). Using only the stars, the sun, and knowledge of currents, these people sailed their double-hulled canoes all over the South Pacific. Colonization of the islands in the South Pacific is believed to have occurred from west to east, despite the presence of easterly trade winds and currents. Nevertheless, linguistic, cultural, physical and archaeological similarities betwen Pacific islanders and Asians support this theory (Finney, 1976).
Ben Finney proved that long-range sailing without navigational instrments
could be done successfully in 1976 when he sailed a Polynesian replica
double-hulled canoe from Hawaii to Tahiti and back, a distance of 2,393
miles each way (Fig. 1) (Finney, 1976). The trip south took 30 days, and
the trip back took only 22 days. On a map, the largest distance between
any two islands seperating South America form China is between Sala-y-Gomez,
just east of Easter Island, and Ilsa San Feliz, off the coast of Chile
(Fig. 1). This distance is 1,693 miles, which is 700 miles less than from
Tahiti to Hawaii, a trip which took only 22 days (NGS, 1999) and no modern
equipment. Using a distinctive pottery called Lapita, archaeologists were
able to trace migration of Polynesians from New Guinea to Melanasia, Fiji,
Samoa and Hawaii by 1500 B.C.(Finney, 1976). The statues on Easter Island
bear more resemblence to Polynesians than to native South American Indians
(Ward, personal communication). If the evidence shows that the Polynesians
colonized islands over 10,000 miles of ocean, why is it hard to believe
that they at least visited a continent less than 2,000 miles away?
Surely sometime within the last 3,500 years, voyages of less than 2,000
miles which may have taken less than 20 days occurred. True, the trade
winds predominately blow from east to west at this latitude, and would
hamper sailing eastward, however, during the month of November, December
and January, violent westerly gales can blow for weeks at a time, providing
strong wind for eastward sailing (Finney, 1976). Additionally, winds below
40°S latitude predominantly blow from west to east, providing an alternate
route to sail to South America (NGS, 1999). It is easy to imagine voyages
from Tahiti to South America by island hopping, and even easier to imagine
voyages from Tahiti to Asia. Why then is it not widely accepted that ideas
and plant germplasm could have crossed the Pacific?
Table 1. Introduced plants in Hawaii preceding European exploration
(John, et al. 2000)
In Hawaii, there are 27 plants that are known to have been brought to shore from India, Asia, Indonesia, America and even Africa (Table 1). Throughout French Polynesia, which contains some of the easternmost Pacific islands, crops were grown before Europeans arrived that originated on both sides of the Pacific. It is undeniable that contact took place between America and Pacific Islanders.
Archaeological evidence is lacking for most assertions of Polynesian contact with South America, most likely due to the corrosive seawater which would obviously be in contact with most possesions of the Polynesians. Additionally, the Polynesians did not form metal tools, but used wood instead for almost everything they needed. It is not surprising in the least that archaeological evidence is not abundant in support of trans-Pacific cultures. On the flip side, there is little evidence against it.
The presence of the idea, if not the actual product, of Central American corn in China, the cultivation of South American sweet potatoes in Polynesia, the use of Indonesian coconuts and bottle gourds in South America, the presence of over 25 Asian/Indian native plant species in Hawaii, as well as the other 90 or so genera present on both sides of the Pacific by 1400 clearly indicate some form of intentional or unintentional human transfer of plant germplasm which significantly preceded European exploration of this part of the world. The means have also been identified, as Polynesians clearly had the ability for sucessful long-range seafaring, as proven by multiple voyages of primitive replica vessels.
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