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Posted on 10/17/2007 11:53:45 AM PDT by decimon
Cashew nut fossils have been identified in 47-million year old lake sediment in Germany, revealing that the cashew genus Anacardium was once distributed in Europe, remote from its modern “native” distribution in Central and South America. It was previously proposed that Anacardium and its African sister genus, Fegimanra, diverged from their common ancestor when the landmasses of Africa and South America separated. However, groundbreaking new data in the October issue of the International Journal of Plant Sciences indicate that Europe may be an important biogeographic link between Africa and the New World.
“The occurrence of cashews in both Europe and tropical America suggests that they were distributed in both North America and Europe during the Tertiary and spread across the North Atlantic landbridge that linked North America and Europe by way of Greenland before the rifting and divergence of these landmasses,” explain Steven R. Manchester (University of Florida), Volker Wilde (Forschungsinstitut Senckenberg, Sektion Palaeobotanik, Frankfurt am Main, Germany), and Margaret E. Collinson (Royal Holloway University of London, UK). “They apparently became extinct in northern latitudes with climatic cooling near the end of the Tertiary and Quaternary but were able to survive at more southerly latitudes.”
The cashew family (Anacardiaceae) includes trees, shrubs, and climbers prominent in tropical, subtropical, and warm temperate climates around the world. A key feature is an enlarged hypocarp, or fleshy enlargement of the fruit stalk, which is a specialized structure known only in the cashew family.
The researchers examined possible fossil remains found in the Messel oil shales, near Darmstadt, Germany, which are dated to about 47 million years before the present and reveal the presence of a “conspicuously thickened” stalk. In four out of five specimens, this hypocarp was still firmly attached to the nut, indicating that the two were dispersed as a unit. According to the researchers, the size and shape of the hypocarp – like a teardrop and two or three times longer than it is wide – support its assignation to the Anacardium genus, common to South America, rather than the African Fegimanra genus, though the fossils have features common to both.
“The occurrence of Anacardium in the early Middle Eocene of Germany suggests . . . that the two genera [Anacardium and Fegimanra] diverged after dispersal between Europe and Africa,” the researchers write. “Presumably, Anacardium traversed the North American landbridge during the Early or Middle Eocene, at a time of maximal climatic warmth, when higher latitudes were habitable by frost-sensitive plants.”
The astoundingly close similarity between the fossil and modern day Anacardium also indicates little evolutionary change to the cashew since the mid-Eocene period: “Although cashews have been cultivated for human consumption for centuries, it is clear that they were in existence millions of years before humans. The cashew had already evolved more than 45 million years ago, apparently in association with biotic dispersers,” they write.
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A major outlet for botanical research since 1875, the International Journal of Plant Sciences presents the results of original, peer-reviewed investigations from laboratories around the world in all areas of the plant sciences. Topics covered include genetics and genomics, developmental and cell biology, biochemistry and physiology, morphology and structure, systematics, plant-microbe interactions, paleobotany, evolution, and ecology.
Steven R. Manchester, Volker Wilde, and Margaret E. Collinson, “Fossil Cashew Nuts from the Eocene of Europe: Biogeographic Links Between Africa and South America.” International Journal of Plant Sciences 68(8):1199-1206.
Nut ping. ;-)
So, 47 Million years ago, Europe was as warm as (e.g.) northern Brazil is today. Europe was a tropical country at least 5 degrees C warmer than in our current period of “runaway climate change”.
I can’t remember why I brought this up. Something to do with the Nobel Prize, but what it was escapes me.
Not if you're talking 47 million years ago, you're not. Primates in the early Eocene resembled primitive lemurs and lorises, and weren't anything like our immediate ancestors.
http://www.raceandhistory.com/historicalviews/ancientamerica.htm
That's why lobsters don't have a chance! Little butter and garlic, ..... mmmmmmmmmmmm!
I meant that plants may have spread on their own sooner rather than as human cargo later.
Female and minority lemurs and lorises suffered the most.
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Thanks decimon. |
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They might have been spread by African Swallows laden with cashews. Nee
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Just goes to prove that there were nuts all over.
Nothing more to do - perfection achieved. Once the cashew evolved, it had to wait until the martini caught up.
Apparently Europe used to be warmer than it is today.
(Yeah, it was probably also not in the same spot 47 million years ago, but who can pass up a jab at global warming when it is offered up on a platter.)
:’)
And Europe should have been smaller than today due to higher sea levels back then. Higher sea levels, hence salted cashews. That's my theory, anyway.
Hmmmm. Fossilized cashews. I think I have some in my freezer. I’m going to eat those for breakfast...
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