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Date: | Thu, 14 Jun 2007 07:47:35 -0400 |
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J. Waggle wrote:
> I'm going back about 100 million years or so in creating my honeybee timeline.
An excellent reference on the evolution of the honey bee would be
"Asian Honey Bees" by Ben Oldroyd (2006). In it he describes the
"oldest known bee fossil", a bee preserved in amber found in New
Jersey and estimated at 80 million years old. This is not a true honey
bee but is similar to the modern genus Trigona, a stingless social
bee. He writes that open nesting honey bees appeared in Southeast Asia
6-10 million years ago, and that cavity nesting bees emerged more
recently, "possibly in the Himalayan region". This would still be an
ancestor of the modern Apis mellifera. He suggests that A. mellifera
and A. cerana derive from a common ancestor that was isolated by the
expansion of desert areas of the Middle East. The time of divergence
is unclear but divergence of the mitochondria suggests 3 million years
ago. This would make the honey bee a "relatively young species", like
Homo sapiens.
There is some evidence that the "European Honey Bee" actually
originated in Africa:
> The coexistence of three mitochondrial lineages in north-eastern Africa provides support for Ruttner's (1978) hypothesis that this area is the probable centre of origin for Apis mellifera. Note, however, that the Horn of Africa and the Rift Valley are the main channels of colonization from Asia to Africa.
As an aside:
> scientists estimated the time of divergence between species by studying the sequential arrangement of nucleotides that make up the chain-like DNA molecules of each species. The number of mutations in the DNA sequence of a species, compared with other species, is a gauge of its rate of evolutionary change. By calibrating this rate with the known time of divergence of a species on another branch of the tree-like diagram that shows relationships among species, scientists can estimate the time when the species they are studying evolved. Using this calibration time, the team estimated that the human-chimp divergence occurred at least 5 million years ago
--
Peter L. Borst
Ithaca, NY
USA
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