Title: Re: paleonet Homo sapiens / H. erectus
introgression
Evolution of separate populations of Homo
sapiens could have happened if H.
erectus and H. sapiens populations experienced introgression in more
than one
place. This seems like a reasonable
scenario. - SH
This is the genetic way of expressing the "partial
replacement model" summarized in the link Ana Pinto posted in an
earlier message.
http://www.cartage.org.lb/en/themes/Sciences/LifeScience/PhysicalAnthropology/HumanGeneticEvolution/EarlyModern/EarlyModern.htm
A figure from that page still bothers me. Both the trees
for the "replacement model" and the "regional
continuity model" both show separate transitions from H.
erectus to "archaic" H. sapiens on different
continents with modern H. sapiens "out of Africa"
replacing the archaic form while the "regional continuity model"
show repeated introgression events.
It doesn't seem any more likely that the archaic form of
sapiens would develop independently than would any other
form.
Is this willingness to accept separate origins of the same
species induced (at least in part) from vague memories of pre-plate
tectonic puzzlement over identical shallow-water and terrestrial
species showing up in widely separated locations?
Bill
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William P. Chaisson
Adjunct Assistant Professor
Department of Earth and Environmental Sciences
University of Rochester
Rochester, NY 14627
607-387-3892