26-04-2003, 01:24 PM
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tomato existed before the potato tomato? Solanum or Lycopersicon
In article , wrote...
I do not have proof of that claim. For I think the genome of the potato and
tomato plants are decades away from obtaining and the comparing of those
2 genomes. The wild potato and wild tomato not the hybridized domestic
stocks.
But I think I can make the claim from commonsense reasoning. That the
wild tomato was borne in the hot jungles and outlying regions of South
America in a habitat that was not harsh. The potato on the other hand was
born in a habitat of harsh conditions, cold, arid, high in the mountains and
this required adaptions. The adaptions were that the tomato proclivity to throw
shoots from its vining stems became a potato root tuber and to store nutrients
in the tuber for the high dry mountains of South America. In this view the tomato
extended its range from the easy life in the hot moist jungle of South America
and extend that into the high, cold, dry mountains.
Well, in a sense you're probably more or less right,
with some rephrasing:
The last common ancestor of all modern tomatoes and modern
potatoes would actually be neither a tomato or a potato, but
yes, it would undoubtedly be more like the tomatoes in lacking
tubers. The tubers of the modern potato species are a new
feature that will have evolved in that lineage some time
after its separation from the line leading to modern tomatoes.
And yes, potato tubers [like similar organs in many other plants]
undoubtedly do often serve as storage depots for starch and
water, etc., that can help the plant survive a dormant
period or a prolonged season of unsuitable growing conditions.
So, you may well be basically right about the possible ecological/
natural selective basis for the origin of tubers in the potato
line.
[The "hot moist jungle" vs "cold dry mountains" bit may be a tad
inaccurate, but nevermind...]
cheers
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