[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
This may be getting tangential to our subject, and I will make this my
last posting, no matter what anybody calls me.
To repeat, my definition of fossil is "remains or direct indication of
I guess some of you think that is too general, or that "prehistoric" is
not a good definitive attribute.
Bonnie said (7/2/97; 8:20a):
>Should we not consider an insect encased in amber that is only 5 ka
>to be not a fossil, but consider a Tr coral with its original aragonite
>to be a fossil, PURELY ON THE BASIS OF THEIR AGES? Clearly, this is
>not good science. In fossilization, age confers no special characters.
Well, it is one way to sepcifiy in unequivocal terms, what a fossil is.
Of course, you may like to specify what a fossil is in OTHER unequivocal
terms. And it may be your goal to be very precise and make fine
distinctions. I think we should do that later, after everybody
understands the more general term.
In Bonnie's original posting, alteration ("remineralization") was the one
critical test. I once taught a college-level course dealing with what is
good science and what is not, and there is nothing in my background
stemming from that or other experiences which show any procedural or
conceptual reason to say that a definition in which age is the critcal
factor is not as good as a definition in which alterations is the
critical factor, hence that "age" is not good science, but "alteration"
is. Different, yes; better or worse as science, I don't think
definitions can be so judged.
Who, then, is the final arbiter of the "correct" definition? Well, it's
what definition wins out by preference among those who use the term.
It's like the question "What is science?" It's what scientists say it
is, or what they do.
Consider these published definitions for fossil:
"the remains, traces, or imprints of once-living organisms preserved in
the earth's crust" (Boardman, Cheetham, and Rowell, eds., FOSSIL
INVERTEBRATES, 1987, Blackwell Scientific Pubs., p. 1)
"the remains of prehistoric life" (McKinney, EVOLUTION OF LIFE, 1993,
Prentice Hall, p. 122)
"remains of organisms that lived in the distant past and have been buried
and preserved in sediments and sedimentary rocks" (Stearn and Carroll,
PALEONTOLOGY, 1989, John Wiley, p. 3)
"the preserve remains of past life on earth, or indirect traces of such
life" (Lane, LIFE OF THE PAST, 1978, Merrill, p. 1)
"any remains, trace or imprint of a plant or animal that has been
preserved, by natural processes, in the Earth's crust since some past
geologic or prehistoric time" (Goldring, FOSSILS IN THE FIELD, 1991,
Longman, p. 204)
"remains of an ancient organism, or the trace of such an organism"
(Nield and Tucker, PALAEONTOLOGY--AN INTRODUCTION, 1985, Pergamon, p. 1)
"any record of past life, such as actual bones, shells, teeth, but also
including impressions, footprints, burrows, etc. (Dott and Prothero,
EVOLUTION OF THE EARTH, 1994, McGraw Hill, p. g-4)
OK, now I hope this doesn't spur a mad rush to look up all of the
definitions available. These are the references I had at this moment at
arm's reach that included an explicit definition for "fossil," and I am
confident that just about anybody could ferret out a definition that
seems to be at odds in some way with these. But note that at least all
of the ones above, except the first, specify or imply that fossils are
ancient, whereas none specify that they must be altered, or
I didn't cite the definition from the classic textbook by Moore,
Lalicker, and Fischer (1952) because the book is so old, but they
actually specify that very young objects are excluded from consideration
as fossils. In other words, great age is critical.
So, I rest my case, and note the truism(??) that all of the truly great
ideas in science are simple (well, at least, I heard that somewhere). I
think the simpler we keep things, the better.
Bonnie also said (same posting):
> . . . the insistence on 10 ka, is meaningless, as would an insistence
>on 1 Ma, or 1 Ga, as a 'prerequisite age'.
My opinion is that it is a matter of definition, and you simply define
what is meaningful. Clearly, this ("meaningfulness") is a highly
subjective matter, whereas at least the definition is objective. If you
don't like the conventional definition, make your own and wait to see if
it works, or if people jump all over it, as they did with the
"remineralization" definition. In this case, 10 ka is a guideline to the
boundary between the Pleistocene and Holocene, hence to what is and what
is not a past geologic age. Harping on 10 ka as if it were a totally
arbitrary cut-off, standing on its own, misses the point.
Norman R. King tel: (812) 464-1794
Department of Geosciences fax: (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712 e-mail: email@example.com