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I basically agree, although I am not wiling to give up on my hope (unscientific as it may be) that the Neanderthals were my ancestors. I do think there is some evidence of intermingling between H.s.s. and H.s.n. I also think the multi-origin theory is an idea that has outlived its usefulness. --- Nikolaus Malchus <n.malchus@gmx.net> wrote: > Hi Nancy, Sylvia and all, > > 1) Without any polemics, one can invent innumerable > hypotheses on something. > However, a new (although perhaps not really new here) > scientifically sound > and acceptable hypothesis needs to accomodate (explain) > facts and > observations in a better way than the one it pretends to > substitute. > > 2) Let's define ingression (not mine): "incorporation of > genes of one > species into a gene pool of another species". This is > known from e.g., > bacteria (though species definition is different here), > plants, > invertebrates, not sure about amphibians. Correct me, but > I am unaware of > any example from Mammalia (tiger-lyon?). Examples of > cross fertilisation > between mammalian species are known (e.g., donkey x horse > = mule) but these > hybrids are not fertile and therefore cannot reproduce to > give a new > species. In theory, it might exist in humans (or > hominoids) but in the > absence of the slightest indication of its existence > (e.g. cross > fertilisation of ape species and reproducibility between > these hybrids), the > biological species concept (hypothesis) fits human > evolution better then the > hypothesis of reticulate speciation (in humans). In > addition, the fact that > the genetic differences between today living humans are > so extremely minimal > strongly supports a common origin. > > 3) Geographic isolation: the common house mouse is the > same in China and > Europe (and probably the Americas) even though one would > expect little gene > flow between these populations. I would think that humans > are/were at least > as mobile as mice. > > 4) According to current knowledge, Homo sapiens > neandertalensis is not our > ancestor. If it really was a subspecies of Homo sapiens > this would be an > example of evolution within (not of) separate populations > of Homo sapiens. > However, not even here is a sign (I am not aware of any) > of intermingling > between H. s. sapiens and H. s. neandertalensis although > the latter also has > a wide geographic distribution (Europe, Asia, Africa). > > All in all, at present I fail to see how introgression > between human species > could be a "reasonable scenario" (scientifically sound > hypothesis). > > 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 > > > > I agree that H.s. could spread after evolving from one > > group of H.e. I just don't think that Homo erectus in > > different isolated groups could have evolved into the > same > > species everywhere. I have read about that theory in > > several places, for instance, in The Real Eve; I'll > have to > > get youthe name of the author. I should probably add > that > > I am not a scientific professional; i'm a criminal > defense > > lawyer, but I often wish I had stayed with paleontology > > instead. If I've mistaken what I read I hope someone > will > > email me and let me know. > > --- Bill Chaisson/Deirdre Cunningham > <chaisson@netacc.net> > > wrote: > > > >I'm not convinced that it's racist, but I still > don't > > > agree > > > >with it. -And my grandfather was from Alabama, so > we > > > could > > > >be cousins! I'm just a few miles away from Dayton, > Tn, > > > >home of the Scopes trial. > > > > > > Isn't this issue something that can be settled with > DNA > > > evidence? > > > > > > I also don't understand why it seems unlikely that a > > > large highly > > > mobile and highly adaptable organism like Homo > sapiens > > > could not > > > become globally distributed after originating from a > > > single > > > population of H. erectus. > > > > > > Please provide a reference where the multi-origins > > > evidence is presented. > > > > > > Thanks, > > > Bill > > > -- > > > --------------------------------------------------- > > > William P. Chaisson > > > Adjunct Assistant Professor > > > Department of Earth and Environmental Sciences > > > University of Rochester > > > Rochester, NY 14627 > > > 607-387-3892 > > > > "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/ > > > > > > > > > > > > -- > --- > 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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