Archaeopterygid bird from China

Wed Mar 30 13:18:41 CST 2005

Science deals with doubt and guesswork and choosing some less than
absolutely correct theory to act on given a tolerable risk. Few scientists
figure they will ever know anything about nature for sure.

So one inclines to suspect an origin near the earliest occurrence of a
fossil, though maybe would not bet on it UNTIL the suspicion, notion or
hesitant suggestion starts to fit in with other information, like
evolutionary complexity that seems to fit in with the idea of migration from
the suspected site or origin, or such.

It is the grandly interconnecting hypotheses that add up to a complex and
broadly documented theory of a point of origin that includes nicely
dovetailing other theories that convince a scientist that something is a
decent scientific theory that can be used to guide further research.

No, the earliest fossil is no sure guide to point of origin, but that's the
first step in scientists' pursuit of a complex theory of origin that
includes as much as possible of the whole earth, all fossils, and present
life within a shared framework of fact (well-documented observations).

______________________
Richard H. Zander
Bryology Group, Missouri Botanical Garden
PO Box 299, St. Louis, MO 63166-0299 USA
richard.zander at mobot.org <mailto:richard.zander at mobot.org>
Voice: 314-577-5180;  Fax: 314-577-9595
Websites
Bryophyte Volumes of Flora of North America:
http://www.mobot.org/plantscience/bfna/bfnamenu.htm
Res Botanica:
http://www.mobot.org/plantscience/resbot/index.htm
Shipping address for UPS, etc.:
Missouri Botanical Garden
4344 Shaw Blvd.
St. Louis, MO 63110 USA

-----Original Message-----
From: John Grehan [mailto:jgrehan at SCIENCEBUFF.ORG]
Sent: Wednesday, March 30, 2005 12:41 PM
To: TAXACOM at LISTSERV.NHM.KU.EDU
Subject: Re: [TAXACOM] Archaeopterygid bird from China

> I thought the example in question was referring to a group - the
family
> Archaeopteryidae.  Given that fossils occur in both Europe and China,
and
> the Chinese fossils are both older and, quoting Ken, seem  "to be a
> slightly
> more generalized, primitive member of Archaeopterygidae," it seems
> reasonable to me to hypothesize (not claim) a Chinese origin.

The location of the oldest fossil has no empirical content about the
origin of a group. In the given example the older/generalized fossil may
occur in China, but that does not, of itself, suggest or show that the
group originated in that area before originating in another. It is
possible, for example, that the group arose from a widespread ancestor
that was in both locations, and the pattern of fossil distribution
represents the sequence of subsequent differentiation (thus the ancestor
might split into two descendant lineages, one of which happens to be
more primitive/generalized and has an older fossil record).

  This could
> be challenged by finding even older fossils in Antarctica or Europe,
or
> anywhere else.  If all reports of even older fossils came from the
same
> area, I would take that as cumulative evidence (as with hominids) that
> that
> is the likely place of origin.

But it seems to be that the location of the older fossils is 'evidence'
only because one has already decided that this is what they mean in
terms of origin (i.e. if one has decided that the location of the oldest
fossils is empirical evidence for the center of origin then the location
of the oldest fossils is evidence for the center of origin).

John
>
> Cheers,
>
> Dick J.
>
> John Grehan wrote:
>
> > Dick,
> >
> > It seems non scientific in that the fossils themselves do not lead
to
> > the hypothesis. The hypothesis comes from somewhere else. For
example,
> > why would one need to hypothesize that a taxon had its origin at or
near
> > the location of the oldest fossil? And how can any further fossils
> > 'test' that proposition. If one found an older Archaeopterygid bird
in
> > Antarctica, for example, one would still not be any the wiser about
the
> > initial hypothesis, or even that a taxon has an origin associated
with
> > any one particular location.
> >
> > I see the example with hominid fossils being slightly different in
that
> > a group may be seen to have evolved over the range where it occurred
(as
> > opposed to where it does not have any records) although its not
> > necessarily any more real as the flores skeleton (with all its early
> > hominid features) shows. Searching for the ultimate center of origin
> > seems to come from theory rather than the empirical record. At least
> > that's my take on it.
> >
> > John
> >
> > > -----Original Message-----
> > > From: Taxacom Discussion List [mailto:TAXACOM at LISTSERV.NHM.KU.EDU]
On
> > > Behalf Of Richard Jensen
> > > Sent: Wednesday, March 30, 2005 12:21 PM
> > > To: TAXACOM at LISTSERV.NHM.KU.EDU
> > > Subject: Re: [TAXACOM] Archaeopterygid bird from China
> > >
> > > I woud submit that the location of the oldest known fossil can be
used
> > to
> > > construct a simple scientific hypothesis  - the taxon had its
origin
> > at or
> > > near that location.  This becomes a hypothesis and can be tested
as
> > more
> > > fossils come to light. The fact that virtually all of the earlist
> > known
> > > hominid fossils come from east Africa seems pretty good reason to
> > > hypothesize that that is where they evolved.   What, exactly, is
> > > non-scientific about this?
> > >
> > > Cheers,
> > >
> > > Dick J.
> > >
> > > John Grehan wrote:
> > >
> > > > Interesting to see new material for the origin of birds, but I
would
> > > > caution that the fossil record has nothing to do with the family
> > > > originating in any particular place over any other. That's just
a
> > > > theoretical postulate going back to Darwin and it has no
necessary
> > > > relationship with reality. The location of the oldest known
fossil
> > has
> > > > no necessary relationship with the distribution of a group at
its
> > > > phylogenetic origin. The location of the oldest fossil is just
that
> > -
> > > > the location of the oldest fossil. Everything else (I would
submit)
> > is
> > > > largely, if not wholly, a fanciful conjecture masquerading as
> > science
> > > > (and successfully doing so judging by the widespread
acceptability
> > of
> > > > this approach in scientific journals).
> > > >
> > > > John Grehan
> > > >
> > > > > -----Original Message-----
> > > > > From: Taxacom Discussion List
[mailto:TAXACOM at LISTSERV.NHM.KU.EDU]
> > On
> > > > > Behalf Of Ken Kinman
> > > > > Sent: Wednesday, March 30, 2005 11:10 AM
> > > > > To: TAXACOM at LISTSERV.NHM.KU.EDU
> > > > > Subject: [TAXACOM] Archaeopterygid bird from China
> > > > >
> > > > > Dear All,
> > > > >        A close relative of Archaeopteryx has been described
from
> > > > China.
> > > > > Whether it is from the Jurassic or Lower Cretaceous is
uncertain,
> > so
> > > > it
> > > > > could be same age as Archaeopteryx or a bit younger.  Whatever
its
> > > > age, it
> > > > > seems to be a slightly more generalized, primitive member of
> > > > > Archaeopterygidae.  This indicates to me that this family more
> > likely
> > > > > arose in Asia (with Archaeopteryx being a specialized offshoot
in
> > > > Europe).
> > > > > Therefore Archaeopteryx is slowly losing its special status,
and
> > this
> > > > will
> > > > > continue as even more primitive members of the family are
> > discovered
> > > > in
> > > > > Asia.  The title of the paper is poorly worded, but here's the
> > > > citation:
> > > > >
> > > > > Ji Q., Ji S., Lu J., You H., Chen W., Liu Y., and Liu Y.,
2005.
> > First
> > > > > avialan bird from China (_Jinfengopteryx elegans_ gen. et sp.
> > nov.).
> > > > > Geological Bulletin of China 24(3): 197-205.
> > > > >
> > > > >   ----Cheers,
> > > > >         Ken Kinman
> > >
> > > --
> > > Richard J. Jensen              | tel: 574-284-4674
> > > Department of Biology      | fax: 574-284-4716
> > > Saint Mary's College         | e-mail: rjensen at saintmarys.edu
> > > Notre Dame, IN 46556    | http://www.saintmarys.edu/~rjensen
>
> --
> Richard J. Jensen              | tel: 574-284-4674
> Department of Biology      | fax: 574-284-4716
> Saint Mary's College         | e-mail: rjensen at saintmarys.edu
> Notre Dame, IN 46556    | http://www.saintmarys.edu/~rjensen
>
>