On Sat, 03 Jan 1998 18:20:06 -0600, Glenn Morton wrote:
>SJ>Agreed. Eldredge candidly admits that the fossil record actually
>>shows "truly instantaneous, overnight evolutionary leaps", but the
>>the Neo-Darwinist can always maintain his gradualism by claiming
>>that the gap occurs when the evolution did.
GM>Eldredge admits no such thing according to your own quotation.
>Notice the word 'not' at the end of the first line.
>SJ>"The convenient thing about gaps in the record is that we need not
>>invoke truly instantaneous, overnight evolutionary leaps to explain
>>the transitions we seem to see in our fossils. With perhaps as much
>>as a million years missing, and certainly for such modest change as
>>the column counts in these trilobite eyes, we can easily maintain
>>that evolution is, after all, a gradual, intergradational affair.
>>We might regret not being able to "see" that transition-the gap in
>>preservation unfortunately seeming to occur when the evolution did."
>>(Eldredge N., "Time Frames", 1985, p72)
I think *you* may need to read it again? The "not" refers to the
gradualists' *explanation*, of the gaps in the fossil record, rather
than to what the fossil record actually shows. This is seen by
Eldredge's sarcastic remarks that "The convenient thing about gaps
in the record..." and "...the gap in preservation unfortunately
seeming to occur when the evolution did."
This supported by Eldredge's remarks about the gaps in the fossil
record a few pages further on:
"...if gradualism is the rule, why don't we see any hint of change?
We might not be faced with a perfect record, but if gradualism is
the rule, our sporadic sampling up and down cliff faces should give
us some hints, some directional drifting, from the primitive state
of the ancestor on over toward the condition we eventually find in
the descendant. Why is all the gradual change going on in those
very gaps?" (Eldredge N., "Time Frames", 1985, p75)
On Sat, 03 Jan 1998 23:00:55 -0500, Brian D Harper wrote:
[...]
BH>Sorry to do a hit and run, but I thought I would mention that
>Eldredge (in <Reinventing Darwin>) states that the resolution of the
>fossil record is typically on the order of 10's of thousands of years at
>best. It's good to keep this in mind when talking about
>instantaneous jumps. Nighttime is long and lonely for those poor
>paleontologists :).
Eldredge actually says "five to fifty thousand years". But he adds
that this "estimate" may be "overly generous" becuae "speciation
events may often require even less time to take place":
"As against five to ten million years of stasis, we claimed that
evolutionary change tied up in speciation events-happens rather
quickly. Here we are at the smallest level of resolution of geological
time often (but not always) possible) with the fossil record. Even tens
of thousands of years are usually difficult to decipher in the fossil
record. So our estimates of time required for speciation events were
much hazier than our estimated average durations of species. I came
up with the figure "five to fifty thousand years," which was consistent
with some of the events we believed we had some direct data on from
our own studies...Indeed some evolutionary geneticists have said that
the "five to fifty thousand years" estimate is, if anything, overly
generous. Speciation events may often require even less time to take
place." (Eldredge N., "Reinventing Darwin", 1996, p99)
As the above quote indicates, this "smallest level of resolution of
geological time" is a limit of *seeing* speciation events, not on
the actual speed of the events. It is open to a consistent theist
to believe, on the fossil evidence, that speciation could have been
anything from instantaneous (ie. within one generation), up to tens
of thousands of year. Indeed, in the above quote, between the
elipses I have inserted, Eldredge actually says:
"...evolution looks instantaneous in the fossil record, but is not."
(Eldredge N., "Reinventing Darwin", 1996, p99).
The "but is not" here is a deduction from Eldredge's naturalistic
philosophy, rather than from any palaeontological evidence. In this
he oversteps the mark-he is qualified in *palaeontology*, not in
philosophy or theology. It may be true that there is no
naturalistic way for major speciation events to happen
instantaneously (ie. single-step within one generation). But if
there is a God who is able to intervene in biological history, then
evolution could not only look instantaneous in the fossil record,
but it could in fact be.
On Sun, 04 Jan 1998 12:00:54 -0600, Glenn Morton wrote:
GM>Thank you for pointing out that the resolution of the fossil record is at
>best 10,000 years. I would like to note that the entire panoply of dog
>breeds have been developed over the past 10,000 years. If a future
>creationist only had the wolf from 10,000 years ago and a St. Bernard and
>Chihuahua from today, he to would then argue that there were no connecting
>links between the wolf and these two modern dog breeds. I can see this
>argument appearing in some creationist book in the year 250,019 A.D. If
>there were also a wolf alive today, the future creationist would be able to
>argue that the wolf could not possibly be the ancestor of the St. Bernard
>and Chihuahua because the wolf and these forms live side by side.
This is all very imaginative but it only clouds the issue. Firstly,
we are not discussing common ancestry (even the ICR believes that
dogs came from wolves). Secondly, it says nothing about what we are
discussing, namely *speciation*. All this "entire panoply of dog
breeds" are just varieties of the *one* interfertile species, canis
familiaris:
"In the development of the 110 separate breeds shown here-and
recognized as breeds in modern dog shows-the four ancestral sub-
species have not remained entirely distinct. New strains have often
been helped along by mongrelization, as indicated by the dotted
lines. The fact that dogs of the four different groups can still
interbreed proves that they really are all one species-but one of a
diversity which shows how far selective cross-breeding can carry the
descendants of a single genetic stock." (Moore R., "Evolution",
1964, p87)
The "10,000 years" above refers to the *domestication* and
subsequent artificial selective breeding of the domestic dog, from
wild dogs, *not* to the speciation event(s) which gave rise to canis
familiaris in the first place:
"The dog is the oldest domesticated animal, having been in the
company of man for at least 10,000 years and having originated
probably somewhere in Eurasia 12,000 to 14,000 years ago. It
belongs to the same genus (Canis) as do the coyote, jackal, and
wolf, all of which have been considered to be his ancestors."
("Dog", Encyclopaedia Britannica, 1984, 5:929)
The point is that knowing from the fossil record that the speciation
event(s), that "originated" the dog "probably somewhere in Eurasia
12,000 to 14,000 years ago", tells us nothing about the speed of
that "speciation event(s)". Like all new species, they appear in
the fossil record "all at once and `fully formed.' " (Gould S.J,
"The Panda's Thumb", 1980, p150). Your imaginary "creationist"
therefore is quite entitled to believe that the dog originated
supernaturally and instantaneously, because: a) that is precisely
what the fossil record shows; and b) for the last "10,000 years",
despite some intensive selective breeding and an unusually plastic
gene-pool, the dog has shown not the slightest sign of changing into
a new species-canis familiaris has steadfastly remained canis
familiaris!
God bless.
Steve
--------------------------------------------------------------------
Stephen E (Steve) Jones ,--_|\ sejones@ibm.net
3 Hawker Avenue / Oz \ Steve.Jones@health.wa.gov.au
Warwick 6024 ->*_,--\_/ Phone +61 8 9448 7439
Perth, West Australia v "Test everything." (1Thess 5:21)
--------------------------------------------------------------------