Old rats -

From: NancyB (n.beavan_at_gns.cri-dot-nz.no-spam.invalid)
Date: 07/30/04 

Date: 29 Jul 2004 22:27:40 -0500

Dear George, and Eric:

(sigh)

Eric: you said
"Quote Abstract A consensus has not been reached on the validity of
"old"
(pre-Polynesian settlement) 14C ages for Pacific rat bones from New
Zealand.

Dead right"

No, its inconsequential and a polite way to start an abstract.
Consensus is seldom reached on issues where a paradigm shift is
suggested.

However, the weight of data will support the probability of a certain
observation being valid. And quite frankly, Holdaway and I and other
co-authors have done a significant amount of well organised,
documented and peer reviewed research which stands up rather better
than responses which say "Its wrong." State actual reasons, show
proof with data as to why previous data is wrong. Don't just suggest
possibilities- show me why it is wrong.

Prof Robert Hedges ( Oxford Radiocarbon lab) did a review of all the
data, and processing and analysis. Did you miss that one? Hmmm...
it was right there, in the next issue.

http://www.rsnz.org/publish/jrsnz/2000/24.php

His review of these proceedures could find no reason that the ages
could be wrong with respect to processing and analysis.

Then, its followed by another article once again saying "no, it
isn't".

Again BIG SIGH. That's what we do as scientists: we construct a view,
we modify that view vis data, we argue in press and at mtgs with each
other and we get points for how robust our arguments are ( these
points not actually being redeemable for anything other than beers
from people who agree with you, however.)

And you said:

"Claim: That Rattus exulans has been present in New Zealand 800 years
prior to the Maori settlement of New Zealand..
Refutation 1
In 800 years of occupation of the two main landmasses of New Zealand
we have ‘5' measurable samples of Rattus exulans"

Uh, no -- I suggest you read on.

"Refutation 2
Is/are there any 700 or 600 or 500 or 400 or 300 or 200 or 100 year
before Maori settlement Rattus exulans samples tested and written
up?
And instead of 5 samples of Rattus exulans I'd expect a database of
samples for North and South Islands populations as North Island and
South Island populations are claimed."

Uh, no, again -- read on

ALL I CAN SAY IS:
Do you boys really have no idea of the size of the database?

EIGHTEEN North and South Island kiore dates were published in the
original Nature article ( Holdaway 1996, Nature 384 225-226.

FIFTEEN dates are significantly older than the generally accepted
dates for human settlement.

And yes, there certainly were a RANGE OF OTHER DATES PRODUCED.

The article that you cited
"Differential reliability of C14 ages of rat bone gelatine in South
Pacific history Journal of the Royal Society of New Zealand : 30:
243-261" could only access and collate published ages. There were a
considerable number of ages that had been run during those years that
were not then published - and not included in that article.

In our work 1995 to 1996, there certainly are ages of less than c. 950
yrs BP, and were so interspersed within older dates that analytical
bias or variability in laboratory preparation would have had to be
notably selective.

As a fact, some 32% (n = 14) of subfossil rat bone ages produced
during 1995 to 1996 were determinations of less than 950 yrs BP.

A further test of the system with two modern rats analysed in 1995 (
which were run in the series where ancient rat bone were run)
returned bomb carbon-affected ages that accurately reflect known date
of death to within 5 years.
PS: For the uninitiated - it would be difficult to get spot on bomb
carbon affected ages if a "processing effect" was producing *too old*
dates on rats with unknown ages ( that is, the ancient samples we were
doing at the same time.)

Analytical bias early in the series as cited by Anderson (2000) also
does not account for the accurate dating of a paired sample (bird
bone and moa eggshell) from Hukanui Slab (2995-/+72 and 2905-/+88
yrs BP respectively) in the series which included three “old” rat
dates from the Ernescleu site.

Of the remaining ages greater than c. 950 yr BP produced in that
period, none of the results produced for those samples were thought
to be at odds with the stratigraphic situation in a given excavation
at a natural site (Holdaway et al 2002).

YOU ALSO SAID:
"Holdaway (1996) asserted that sample NZA – 6636 as recovered from
Hukanui #76 by J C Yaldwyn in 1959 is the one in the labelled
matchbox !
Subsequent excavations at this site (Hukanui) do not support the
claim ! The only rat bone taken from the site was a rat jaw bone
(lower
mandible)"

ERIC, I know that you couldn't have known this, but to make a bald
statement instead of asking.... see below...

and GEORGE offers a snark:
"Provenance. Lovely word that.It would appear that it has not had much
usage in this. A labelled matchbox containing 40 year old samples and
a site that yields no more of this bone......."

George, I get samples submitted wrapped in rolling papers that have
been stuck into film caps. At least John Y had a clean matchbox,
labelled it clearly, and got it archived.

John Yaldwin was very up front about the discovery of the bone when he
did excavate it. There is a sweet article from the time in which he
states how he thought it was special, coming from under the Taupo
ash, and is qouted as saying, if only 14C technology could date such
a small sample.

There ***were*** ounces and ounces, dozens and dozens of rat bones
taken from that area/site around that time, by those early
fossickers.

Unfortunetly, they were all thrown into tea tins and tobacco pouches (
sez something about the provisioning of these field trips, ya think?)
and NOT labelled with any excavation information. That's what I saw
in a museum, and it was sad -They were pretty worthless as far as
what age they might be -

A dip into the New Zealand kiore controversy can be amusing. For
those of us who have worked very diligently to gain new insight, its
less fun than it once was -- especially after seven years of work
that has been done six ways to Sunday, and published. The "rats
aren't old" group pose perfectly reasonable questions. They have been
met by long hours in the lab.

The bottom line is: there are v. old rat dates. This isn't about
early settlement. They are not from archaeological sites; they are
from sites such as where ancient owls spat up remains from meals. We
know how diet makes bone look too old. We tested this. We tested for
paired sample agreement, we tested by OSL.

Funny thing happpened at the last NZ Archaeological Society annual
mtg. A paper poll was taken for the question "Old rats: yes or no."

Old rats won.

And if you want to consider what an early introduction of a new
predator to a pristine environ would do to exterpation and
extinction, please do look up the many articles Richard Holdaway has
published, based on his world-class analysis of same for bird
species here in NZ.

 Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
    ** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
                http://www.usenet.com

Relevant Pages