Article View: sci.archaeology
Article #916Re: genetic facts [was: Ashby, botanical facts
From: Ross Clark
Date: Tue, 20 Oct 1998 00:00
Date: Tue, 20 Oct 1998 00:00
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Bernard Ortiz de Montellano wrote:
>
> > Peter Ashby (p-ashby@nimr.MAPS.mrc.ac.uk) wrote on 5 Oct 1998 21:03:48 GMT:
> >
> {Yuri said}
> > Rebecca L. Cann and J.K. Lum are the scholars who are supporting
> > Polynesian -- American links recently based on DNA. They have studied the
> > DNA of living Pacific populations and compared their findings to the DNA
> > of native Americans. They found that several mitochondrial DNA lineages
> > occur both in the Pacific area and among Amerindians.
> >
> > Bonatto et al. actually AGREE with Cann & Lum on this. So this is very
> > significant.
>
> Yuri, I can make no judgement from this. References please. Title,
> Journal, date, volume, page number.
>
> >
> > And thus, your game is up, Peter. Certainly the latest DNA finding cannot
> > be seen as contradicting Heyerdahl. Supporting him is more like it.
>
> Yet again you demonstrate your fundamental misuderstanding of the nature
> of evidence and proof. You even admit yourself that they can be
> interpreted in more than one way. I really am almost ready to give up on
> you. I originally entered this debate because you cross posted to
> soc.culture.new-zealand and your use of science was so appalling I
> couldn't let it pass. I thought (naivly) that I could point out the error
> of your ways and improve your reasoning. It is obvious that my mission has
> been doomed from the start. There are none so blind as them who will not
> see.
>
> Yours pessimistically
>
> Dr. Peter Ashby
>
> Peter,
>
> Obviously Yuri did not want to give you a cite. I finally got connected
> again with a library.:
>
> J. Lum, R.L. Cann, J.J. Martinson, and L.B. Jorde. 1998. �Mitochondrial
> and Nuclear Relationships among Pacific Island and Asian Populations�
> *American Journal of Hman Genetics* 63:613-624.
>
> The bottom line is that both mt-DNA and STR data support an Asian origin
> for Pacific Island (including Rapa Nui) populations. The end of the
> abstract says: �These results are consistent with an initial settlement of
> Remote Oceania from island Southeast Asia [New Guinea, Australia] and with
> extensive postcolonization male-biased gene flow from Near Oceania.�
>
> As usual it is always nice to read the original source rather than
> someone�s tendentious summary. There is no evidence that Cann supports
> Amerindian migration to Oceania. What is needed is a direct quote to that
> effect from Cann.
>
> --
> Bernard Ortiz de Montellano
Thanks for the more recent reference, Bernard. I've had a chance to look
at a couple of the papers referred to earlier, and I thought I'd add some
quotes since Yuri is now talking as if this research "supports
Heyerdahl".
J.Koh Lum, Olga Rickards, Clara Ching and Rebecca L.Cann, Polynesian
mitochondrial DNAs reveal three deep maternal lineage clusters. Human
Biology, August 1994, vol.66, no.4, pp.567-590.
[From the Abstract] Major Group I lineages are common in Remote Oceania
and include about 95% of the Native Hawaiians, 90% of the Samoan, and
100% of the Tongan donors in our sample...This group also contains
non-Polynesian individuals, such as Indonesians, Native Americans,
Micronesians, Malaysians, Japanese and Chinese....Group II individuals
are seen at low frequency (<10%) in Hawaii, Samoa and the Cook Islands
and may represent the predominant maternal lineage group of Papuan
Melanesia. Major lineage group III, not found in Hawaii, tentatively
links Samoa to Indonesia. Our observation of deep maternal genetic
branches in Polynesia today confirms the notion that during the
colonization of the Pacific, mainland Asian immigrants mixed with
Melanesian peoples already inhabiting Near Oceania and carried a complex
assortment of maternal genotypes derived from two distinct geographic
sources to isolated island archipelagoes.
[And an interesting passage from the text:]
Finally, the South American sweet potato is found throughout Polynesia,
raising the question of two-way voyaging from Polynesia or drift voyaging
from the west coast of South America.... The presence of flotsam from
North America in Polynesia and demonstration rafting from South America
indicate that some limited contact may have been possible between eastern
Polynesia and the Americas. Currently, there is a lack of compelling
evidence from archeology, linguistics, or genetics that supports this
idea. (582)
J.Koh Lum and Rebecca L.Cann, mtDNA and language support a common origin
of Micronesians and Polynesians in Island Southeast Asia. Am.J. Phys.
Anthro. 105:109-119 (1998)
We interpret these results as support of a rapid colonization of Remote
Oceania by a closely related group of Austronesian-speaking populations
from Island Southeast Asia. Following this initial settlement extensive
gene flow occurred between these recent migrants and neighboring people
from Island Southeast Asia and Papuan speaking Melanesians without major
impact on the established linguistic relationships. (117)
Sandro L.Bonatto, Allan J.Redd, Francisco M.Salzano and Mark Stoneking,
Lack of ancient Polynesian-Amerindian contact, Am.J.Hum.Genet. 59:253-256
(1996).
Therefore, all the shared sequences between Polynesians and Amerindians
are much more likely explained as a retention of ancestral Asian
sequences by both descendant populations than by an ancestral or recent
post-divergence admixture.
...
In conclusion, the presence of the B lineage and the matching of three
other sequences between Polynesians and Amerindians probably reflect a
shared Asian origin rather than direct contact. Nevertheless, these
results do not rule out the possibilities of still-undetected minor
contact and nonmaternal genetic exchange. (255)
R.L.Cann and J.K.Lum, Mitochondrial myopia: Reply to Bonatto et al.
Am.J.Hum.Genet. 59:256-258 (1996)
...the question of whether there was limited gene flow between Native
Americans and Oceanic populations is unresolved. Rather than make
dogmatic statements, we feel that it is better to encourage the open
exploration of this debate, with more genetic markers and the use of data
already in the literature. (258)
-------------------------------------------
To sum up what Cann & Lum and the other researchers seem to be saying:
- The mtDNA studies support the conventional view of Polynesians as
coming from SE Asia with some Melanesian genetic input.
- Connections between Polynesian and Amerindian groups most likely
reflect their common Asian origin rather than recent contact.
- The possibility of more recent contact cannot be absolutely ruled out,
but at the moment it is not clearly supported by any positive evidence.
Ross Clark
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X-Google-Language: ENGLISH,ASCII X-Google-Thread: f66d0,df6f216fbb8c3d89 X-Google-Attributes: gidf66d0,public X-Google-Thread: fcea6,4a599aa9a3239f6e X-Google-Attributes: gidfcea6,public X-Google-Thread: 1119a6,4a599aa9a3239f6e X-Google-Attributes: gid1119a6,public X-Google-Thread: 1129f3,716126af31e790df X-Google-Attributes: gid1129f3,public X-Google-Thread: 10065c,4a599aa9a3239f6e X-Google-Attributes: gid10065c,public From: Ross Clark <drc@antnov1.auckland.ac.nz> Subject: Re: genetic facts [was: Ashby, botanical facts Date: 1998/10/20 Message-ID: <362C0E6A.476@antnov1.auckland.ac.nz> X-Deja-AN: 403069169 Content-Transfer-Encoding: 8bit References: <bortiz-1910981540210001@ip150.austin17.tx.pub-ip.psi.net> Content-Type: text/plain; charset=iso-8859-1 Organization: University of Auckland Mime-Version: 1.0 Newsgroups: sci.archaeology,bionet.general,sci.misc,sci.bio.misc,sci.anthropology