ancient corn in India

J.R. Pelmont Jean.Pelmont at wanadoo.fr
Fri Jul 11 17:47:29 EST 1997


Hu McCulloch <hmccullo at ecolan.sbs.ohio-state.edu> wrote (excerpt) :

> I have now located the 1992 and 1993 notes by Kumar and Sachan 
> on the genetics of northeastern Himalyan (NEH) maize, demonstrating
> that is more closely related to certain primitive Mexican and 
> Peruvian maizes than it is to the Caribbean maize introduced 
> by the Spaniards into Europe after Columbus.  These NEH maizes
> even have traits in common with teosinte, the wild Mexican ancestor
> of maize, that are completely unknown in modern maizes.  
> K&S conclude on the basis of this genetic evidence that maize
> was introduced into Asia long before Columbus.  
> 

Dear Hu McCulloch,
your message to my mail box is difficult for me to answer, because I
have too little knowledge in these quite disputed topics. I am a
biochemist and enzymologist interested in bioremediation and far from
archaeology and temples of northern India. I am not a geneticist, just
knowing the general methodologies of molecular biology as used by the
geneticists or enzymologists.

I have seen the pictures and it is true that the similarities with corn
are disturbing indeed. However we need convergent data from different
methods. I understand there is already a wealth of data using genetics
and biochemistry. However I still feel a little bit skeptical for
several reasons.

1) There is a risk that the carvings are symbolic pictures of plants
with no desire to be exact representations.
2) According to botanists, the definition of species and varieties may
be difficult to establish, the criteria being ill-defined in some cases.
3) Similarities in chromosome banding and biochemical analysis may
indicate relatedness. But long-range conservation of the genome
structure may occur during evolution, even after a few millions of
years. Maybe I am completely mistakened, because I did not read the
evidence. Anyway if corn had be brought at times older than let us say
one or two thousands years, this is a very short term in evolution and
we should be able to find in Asia modern plants that are really very
similar to maize or teosinte.
4) There is such a huge distance across the Pacific ocean from side to
side that it seems hard to believe in any easy exchange, even using
different islands. Eastern Island West of Chile is about 2.5 thousand
miles from the continent, I believe. The human migratory flow that
occurred many thousands of years ago was clockwise from Eastern Asia
(Malaysia ?) to the Behring connection with America. That is what we can
read. I heard that the back migration westward across the ocean is a
still quite disputed eventuality. Just remembering the Kon Tiki
adventure.

Suddenly I have a crazy thought. But what about birds ? They can fly
huge distances. Not possible here : the seeds of corn are just too big
for getting stuck to the animal and to be transported within its
digestive track. The vegetal contamination of the Galapagos Islands,
that appeared about 5 millions years ago, is a well known subject since
they were visited by Darwin. Plant species were brought from the
continent (minimum : 6OO miles) by birds or attached to floating objects
(or eventually by strong winds). Only organisms surviving salt exposure
or able to fly or swim could get there. No frogs, that's for sure. The
Galapagos have no palm trees or cocos : the seeds are just too big! :-))
Actually just a lot of colored bare rocks and a very strange place
crowded with sea lions, nice birds, penguins, tortoises, iguanas and
.... goats, a pleague brought by man.

Of course I know that none of these objections is able to refute the
initial hypothesis, and this is not my desire to do so. But we have to
be very very prudent, since wanting to prove absolutely any strongly
wanted explanation (a common disease in science) may lead to errors.

A modern tool that will be used by archaeologists to corroborate or
disprove such a situation will be molecular analysis at the DNA and
protein level (1). For instance some people have started to look at human
migration from North to South along America. Trying to know the
filiation of indian populations down to Patagonia. Unfortunately I know
so little about that for the moment that I cannot discuss about it.
But it is very promising. An other example. We just heard (radio, TV)
that german scientists could analyse DNA from Neanderthal remains. This
is fantastic, because the few DNA molecules still attached to the bones
after 3-4 millions of years or so should be more or less damaged. But
now specialists know how, with high technology and precautions to avoid
contaminations with modern DNA. The basis of the analysis is the method
called PCR, now used world-wide, which is a way of amplifying DNA
molecules, i.e. making a new molecule identical to a model, then 4
molecules from the two, then eight from the four, and so on, until
milligrams of homogenous DNA are obtained. The answer was : Neanderthal
people were not our ancestors, but a separate phylum (although this is
still very preliminary).

Coming back to maize, I think such techniques or others in the same line
will be necessary to analyze exactly the plants, to guess their
filiation and evolution and how they were transported and modified after
breeding.

Well, it was a pleasure to discuss with you here, I hope I did not write
too many silly ideas, but if I did who will care finally ? ;-))))
Cheers.

__________
(1) This technique has already been applied to ancient remains, such as the
momified body of Ramses II. There is a story about that. Because the famous
king was dangerously decaying in the Cairo museum, he was brought here years
ago to the atomic center at Grenoble, to be irradiated. There was of course a
lot of care but curiosity around the relique. A colleague of mine stole a tiny
chip to do some electron microscopy. There was a great excitement, because the
pictures revealed beautifully preserved mitochondria. But it was a mistake. A
closer look revealed that the mitochondria were in fact those of the fungi
growing on the king's body !!! :-/

Oh boy ! (as you say in the States) This was again a rather long post, but it
is because I have some enough free time before vacation !

-- 
jean.pelmont at ujf-grenoble.fr
Fax (33)0 476 51 4336



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