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I have often thought that chimps should be Homo pan, but I ahve to admit it never occurred to me that maybe Homo erectus was really H.s.e. Thanks for expanding my mind! --- Nikolaus Malchus <n.malchus@gmx.net> wrote: > Thanks, Bill for the link to this nice summary. > > Now I understand. We are not talking about introgression > between species but > "subspecies". Free interbreeding between subspecies of > the same species are > part of the definition (our definition, of course) of > subspecies. There are > no genetic barriers. > In this case I find all hypotheses mentioned in that > summary "reasonable > scenarios". > > Somebody, earlier on the list (sorry don't remember who) > already said that > it is only necessary that H. erectus becomes H. sapiens. > That we seperate > the involved taxa on the species level is artificial and > in this case > obviously misleading. Biologically, we are talking about > an anagenetic > process not a phylogenetic one, and 'erectus' might be > better called H. > sapiens erectus. In this sense, Wolpoff's 'regional > continuity model' is > perfectly acceptable. And it does not at all imply that > modern H. sapiens > evolved iteratively. > "H. s. erectus" (:-), may have regionally developed > different superficial > characters but the process did apparently not lead to > genetic isolation and > allowed interbreeding as the summary and the laddered > fork (Wolpoff's > original graph???) suggests. So the fork spikes are > between regional > variants (at most), i.e. still anagenetic. > > Apologies for my misunderstanding of the problem. > > Cheers, > > Niko > > > > >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 > > -- > > --------------------------------------------------- > > William P. Chaisson > > Adjunct Assistant Professor > > Department of Earth and Environmental Sciences > > University of Rochester > > Rochester, NY 14627 > > 607-387-3892 > > -- > --- > ADDRESS: Dept. de Geologia/Unitat Paleontologia, > Universitat Autònoma de > Barcelona, Campus, > Edifici Cs, 08193 Bellaterra (Cerdanyola del Vallès), > Catalunya, SPAIN > --- > Tel xx34-93-581-1464/Fax -1263 > --- > n.malchus@gmx.net (admits larger attachments) > nikolaus.malchus@uab.es (max. 2MB for attachments) > --- > > > "The United States is in no sense founded upon the Christian religion." - George Washington __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/
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