A few weeks ago someone asked when agriculture began. I came across these two distinctions that archaeologists use. "Cultivation" (of plants) means that the farmer cares for the plant, waters it, weeds it,etc., and harvests the plant, without changing its genetics from the wild type. "Domestication" means that the farmer has actually changed the evolutionary path of the plant. Men cultivated wild wheat but because its seeds drop off easily when it is harvested, the new crop was always similar to the harvested wild wheat. Thus it took several thousand years for wheat to show genetic changes as a result of man's intervention.
Corn (maize) on the other hand, was domesticated much more rapidly because it does not sow itself so readily. The corn farmer, wanting to plant a new crop, would naturally choose the biggest and best seeds to plant. The corn we know is much bigger than its ancestor, teosinte.
Thus, the time between cultivation and domestication can be thousands of years.

The corn farmer, wanting to plant a new crop, would naturally choose the biggest and best seeds to plant.

Sounds like plain old survival of the fittest.

Philosophers might ponder the question ... who's in charge here, the humans, or the wheat and corn plants that have domesticated them ????

I hadn't heard of teosinte before. Here is a great picture of it. Having been raised on a farm where they raised corn, you'd think I might have heard of it.

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Sounds like plain old survival of the fittest.

But in this case the "fittest" has been selected as such my man for his own purposes.

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"Cultivation" (of plants) means that the farmer cares for the plant, waters it, weeds it,etc., and harvests the plant, without changing its genetics from the wild type. "Domestication" means that the farmer has actually changed the evolutionary path of the plant.

This is correct. Domestication means implies breeding, that is, a difference between the domestic type and the wild type. Elephants, for example, are not considered domesticated because they are not commonly bred in captivity, nor is there a difference between wild and working elephants. Elephants are generally captured and tamed.

Similarly most fruit trees are not really domesticated, they are selected individuals that are propagated by cuttings. Every Granny Smith apple is essentially from the same tree -- Granny Smith's tree.

So I can assume the Indian elephant diverged genetically from the African elephant prior to any potential meddling by humans.

How would US Midwestern grapes be classified, where presumably domesticated European variants are grafted onto heartier (with regard to climate tolerance) American root stock.

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Originally posted by Myth Jellies:
So I can assume the Indian elephant diverged genetically from the African elephant prior to any potential meddling by humans.

I believe that's the case.

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How would US Midwestern grapes be classified, where presumably domesticated European variants are grafted onto heartier (with regard to climate tolerance) American root stock.

Domesticated, if the European variety is. I don't think the act of grafting un-domesticates it.

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How would US Midwestern grapes be classified, where presumably domesticated European variants are grafted onto heartier (with regard to climate tolerance) American root stock.

Most European grapes are grafted onto American root stock but this has nothing to do with climate - although the vigour of American root stock is the reason. Grapes are a very hardy plant and will withstand very low temperatures. The reason why grapes do best in temperate latitudes is climatic, but slightly more complex. Firstly, and obviously, grapes need plenty of sunshine to develop the sugar that makes them suitable to make into wine - red varieties needing more than white (which is why English wines are generally white). But grapes also don't do well in tropical climes either and this is because of the way they grow. Once they have overwintered they grow very rapidly indeed, producing masses of wood, leaf and, of course, flowers and fruit. This is a very energy-consuming process and the plant needs a period of rest in order to repeat the process the next summer. No winter equals little fruit and poor fruit.

But the reason for grafting has to do with US grape varieties nevertheless. This has to do with an unwelcome American immigrant to Europe. In the 1860s the Phylloxera aphid was inadvertently introduced to Europe probably on imported North American vines. During part of its liofcycle the pest lives in the roots of the vine European vines just could not cope with the attack as their roots were not adapted to deal with it. The entire European wine industry was threatened with a few exceptions where the vineyards were on very dry, sand soil which Phylloxera does not like. Many treatments were tried with little success and eventually someone had the bright idea of grafting European vines onto American rootstock. This worked perfectly since the vigorous American rootstock was able to shrug off the predations of the Phylloxera bug and almost all vines are now European varieties on American roots.

Why did the European industry not simply use American vine varieties? For the same reason that most American vineyards use European varieties; native American vine varieties do not make good wine. I am told, although I've not experienced the taste myself, that they have a "foxy" flavour. Since I've never tasted a fox either I can't vouch for the truth of the assertion. There have been some attempts at hybridisation but, generally speaking, the best wines, no matter where they are made, come from the many European varieties.