Dehler, Bernie wrote:
> Hi all- a question for something I don’t understand. I hear of DNA
> studies to determine where humans originated (out of Africa,
> etc.). But how could that be determined since we don’t even know
> what a ‘human’ is? Seems like the quest assumes there is some sort
> of DNA line where you have a non-human, then a human. Seems to me
> like evolution says change is gradual- no dividing line.
In general, the term "human" when used in a scientific context refers
to the genus Homo. The lineage of the genus Homo would begin with
the first population to diverge from the common ancestor with the
other hominids -- the Australopithicine and Paranthropus lines. The
divisions between higher taxonomic groups do not imply any special
degree of difference -- only the possession of particular defining
derived characteristics. Ultimately origin of a new genus (or any
higher taxonomic group) is a speciation event. Taxonomic categories
above the species are simply consequences of the particular
classification chosen -- higher taxa are subjective entities.
Keith
Keith B. Miller
Research Assistant Professor
Dept of Geology, Kansas State University
Manhattan, KS 66506-3201
785-532-2250
http://www-personal.ksu.edu/~kbmill/
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Received on Thu Jun 19 17:14:54 2008
This archive was generated by hypermail 2.1.8 : Thu Jun 19 2008 - 17:14:54 EDT