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and
Origins 51:50-60 (2001).
NEWS AND COMMENTS
WHAT THIS NEWS NOTE IS ABOUT
This is a brief summary of some highlights of the Geological Society of America's Annual Meeting, held November 9-18, 2000 in Reno, Nevada. The authors attended the meeting and a cumulative total of approximately 100 talks out of over 3 000 papers presented. Abstracts for these talks are published in the GSA Abstracts With Programs 32(7).
SEDIMENTARY GEOLOGY
One of the geologic "fads" at the Geological
Society of America annual meeting for 2000 was the "snowball earth"
hypothesis proposed by Hoffman et al. (1998). Upper Proterozoic diamictites
(conventionally interpreted as glacial tills) are widely distributed over
continents and latitudes, both present and ancient. Equatorial paramagnetic
indicators on multiple continents suggest the entire earth's surface was
frozen at this time (thus the "snowball earth" concept). The
excitement and debate over the new theory resulted in many papers, including
computer modeling studies, identification of new outcrops (e.g., the Red Pine
Shale by Crossey et al. [2000]), reevaluation of old sites, and debates
about "cap carbonates" (carbonates found atop the diamictites in many
localities).
Stanley Awramik et al. (2000), for example, argued once again
for a glacial interpretation of Kingston Range's Kingston Peak Formation.
Steven A. Austin et al. (1994), R. Sigler (1998), and Steven A. Austin
and Kurt P. Wise (1999) had previously interpreted these deposits as submarine
landslide deposits based upon strong current indicators, huge megaclasts,
slumping features, and the absence of autochthonous shallow-water carbonates and
glacial indicators. Awramik et al., however, claimed the presence of such
glacial indicators as "abundant" "dropstones" and striated
boulders as well as autochthonous carbonate. It seems that these claims need to
be reexamined by Austin and Wise.
Another recurrent subject in the 2000 abstracts was the
strong negative carbon-isotope excursion often found in the cap carbonates.
Since sea water usually has C-isotope values only slightly negative (-4) and
organic carbon is strongly fractionated (-20), the negative excursion is thought
to involve a huge dump of organic carbon into the oceans (e.g., a methane
"burp" as suggested by Martin J. Kennedy et al. 2000). According
to Kennedy et al., the molar quantity of organic carbon necessary to produce the
isotope excursion is on the order of magnitude of the amount of carbon necessary
to cap the entire world with a thin carbonate. Cool (methane) seep sedimentary
features are also similar to those seen in cap carbonates.
Yet another possibility might be that the initiation of the
Flood (which Austin and Wise 1994; and Austin et al. 1994 tentatively place
immediately below these upper Proterozoic diamictites) released huge volumes of
pre-Flood organic carbon into the world's oceans. This might not only create
the C-isotope excursion but possibly also force the precipitation of the
so-called "cap carbonates." Perhaps the same mechanism is then also
responsible for the simultaneous excursions in sulfur isotopes (Hurtgen et al.
2000) and oxygen isotopes.
Chris Baldwin and colleagues (2000) presented a novel
interpretation of the Bright Angel Shales in the Grand Canyon region. McKee and
Resser (1945) considered the shales a deepening offshore facies of the Tapeats
Sandstone. Baldwin et al. now report evidences of shallow water, and even eolean
deposition, and report strontium isotope signatures of fresh water in these
beds. In spite of the radical reworking of an iconic model (shallow rather than
deep, dry in place of wet, and fresh for marine), there were not challenges from
the audience.
Several GSA abstracts discussed newly excavated bone beds.
Each of them described the bone as lying in a coarse conglomerate with long bone
orientation indicating deposition in a current. In each case, logs were present
among the bones. One log acted as a current baffle during the deposition of the
bed (and possibly facilitating the concentration of bones). This is true of a
bone bed in the Upper Triassic Chinle Formation (Ziegler et al. 2000) and one in
the Upper Cretaceous Judith River Formation (LaRock et al. 2000).
Kevin Burke and Jeffrey Kraus (2000) reported on the
remarkable extent of the mature Cambro-Ordovician sandstones. They estimate
15×106 km3 of sand deposited over North Africa, Arabia, and
associated sedimentary basins in South America and eastern North America. This
is equivalent to covering all 50 states of the USA with one kilometer of sand!
These sandstones have been carved in one place to produce the famous city of
Petra, and eroded in others to produce the massive sand dunes of the Sahara
Desert. This sandstone unit has the uniformity, thickness, areal extent and
distant source area which Austin (1994) suggests should characterize Flood
deposits. Another example of sediments with broad areal extent uncharacteristic
of the present (but expected in a global Flood) was reported by Andrew Webber et
al. (2000) for Cincinnnatian sediments of mid-continental North America.
PALEONTOLOGY
Among the paleontology papers at a GSA meeting are usually
some which introduce new revelations of biological design
("adaptation" in conventional evolutionary terminology). At the 2000
annual meeting, Tomasz Baumiller and David Meyer reported a design which allows
stalked crinoids to align themselves to maximize food intake. The crinoids
studied are found above wave base in the Great Barrier Reef. They need to
continually and rapidly (in seconds) realign to respond to oscillating currents.
Baumiller and Meyer found that the pinnules passively swivel due to loose,
flexible ligaments aligned perpendicular to the axis and yet remain vertical in
the current due to the shape of inter-element articulation and rigid spines
aligned parallel to the pinnule axis.
It is usual among GSA's paleontology papers to report on
remarkable examples of fossil preservation. As an example, two papers by Arthur
Chadwick and Leonard Brand and students (Carvajal et al. 2000; Esperante-Caamano
et al. 2000), following up on last year's initial report (Esperante-Caamano
et al. 1999), described hundreds of whales preserved in a Peruvian
diatomite. The lack of bioturbation and scavenging, and the remarkable
preservation suggests a taphonomy quite unlike that experienced by modern
whales. This suggests these Miocene/Pliocene sediments were deposited under
conditions of rapid deposition not found in the present. Stefan Bengston (2000)
reports on some remarkably well-preserved, phosphatized Upper Neoproterozoic and
Lower Cambrian embryos which even seem to show cleavage patterns (see also Xiao
and Knoll 2000)! Such embryos argue for the reality of the Cambrian explosion
(preservation is sufficient to pick up soft-bodied forms that may have been
there) and provide exciting specimens to paleontologists working out the origin
of the animal phyla.
The current hot topic in evolutionary theory is "Evo-Devo"
(pronounced EE-voh DEE-voh). The failure of megaevolutionary theory to explain
the apparently rapid origin and subsequent stasis of animal phyla (the
"Cambrian Explosion") has forced theorists to seek new mechanisms of
organismal change. Developmental biology has been appealed to for evidence and
theory (thus the new journal Evolution & Development and the same-named
field, abbreviated "Evo-Devo"). There was an entire Evo-Devo session
at the GSA with 14 papers, including one by Stephen Jay Gould, the abstract of
which did not appear in the published Program. This special session, including
four invited papers, was an attempt to synthesize developmental biology and
paleobiology.
One of the invited papers was a review by Rudy Raff (2000).
He reminded the audience that Ernst Haeckel's claim (e.g., see Pennisi 1997)
that all animals develop through similar first stages is contradicted by the
observation that extremely divergent steps occur prior to similar steps.
He calls this a "developmental hourglass." He also reminded us of the
extreme robustness of development (e.g., genome elements from a fly placed in a
developing echinoid results in the animal initially developing as if it were
heading for a fly/echinoid chimera, but ultimately adjusting and becoming a
perfectly good echinoid). This suggests that development is designed to survive
substantial perturbations in early growth. It also suggests that mutation is
going to have a very hard time modifying organisms according to the
"needs" of evolutionary theory.
Raff also reviewed a couple examples of echinoderm species
(e.g., two similar species of the starfish genus Patriella) which
have adult similarity, and yet have radically different early developments. This
is rather difficult to explain in conventional evolutionary theory. Raff also
claimed that multiple times among the echinoderms, identical larval forms have
convergently evolved. The rapid origin of alternative developmental pathways
indicated by these latter two examples may be better explained by Todd Wood's
AGEing (altruistic genetic elements) hypothesis (Wood, in review a).
Eric Davidson's (2000) invited Evo-Devo paper briefly
reviewed regulatory genes and their theoretical impact upon evolution. Davidson
argues that the differences among animal phyla are largely found in the
regulatory gene network both during development and in the adults. Davidson
describes these regulatory networks as "hard-wired" into the organism's
genome. He claimed to deliberately use an analogy from humanly designed
electronics systems because of the mind-boggling complexity and
"if-then-else" statement-type logic of the system. Davidson
focused on outlining the incredible complexity of what he calls the
"Type I Embryonic Process" which results in the production of
larval forms in many bilateria.
A recently suggested and popular construct in evolutionary
theory for the origin of the animal phyla is the development of "set aside
cells" in larval forms as a place to evolve adult animal complexity while
the larval form supports both itself and these new cells. It is difficult to
explain how such complexity is generated by selection in such cells, and it is
difficult to explain why natural selection would not select against the organism
which possessed these energy-sapping (i.e., parasitic) cells.
Davidson alludes to yet another problem with this hypothesis
in that the level of complexity in the regulatory system of these set-aside
cells is literally orders of magnitude greater than that of the
"Type I Embryonic Process" which produces the larvae. Note also
that all this must occur before the Cambrian Explosion. Davidson repeatedly
stressed the fact that "There is no simple bilaterian."
Early evolutionary development of complexity was a repeated
theme in the Evo-Devo talks. Colin Sumrall (2000) argued that the 2-1-2
ambulacral (referring to rows of tube feet) symmetry (i.e., in some sense the
most complex ambulacral symmetry) was the first echinoderm symmetry and all
other "simpler" symmetries found in the fossil record and the present
are developmental modifications (simplifications) of that more complex theme.
Gould shared his conviction that the earliest bilateria must have had the full
complex of hox genes, and any deviation from this has been more or less
degeneration.
Abundant homoplasy (evolutionary parallelisms and reversals),
with its attendant evolutionary consequences of convergent, parallel, and mosaic
evolution was yet another theme which resurfaced repeatedly in the Evo-Devo
talks at GSA. Although Sumrall's hypothesis seems to make some sense of the
echinoderm disparity, it also requires the repeated, independent (convergent)
evolution of the various reductions of that symmetry. Here then is an example of
a hypothesis which suggests a phylogeny in a group which has been hitherto a
phylogenetic nightmare, but which now requires a mind-boggling amount of
convergent evolution (i.e., the kind of ubiquitous homoplasy predicted by Wise's
[1998] mosaic network hypothesis). Other examples of homoplasy included Raff's
(2000) reminder that echinoderm larval forms evolved multiple times among the
echinoderms.
Yet another repeated theme in the Evo-Devo talks was
developmental bridging of fossil record gaps. Megaevolutionists believe that
many transitions between major animal groups might have occurred in larval or
early adult development. If so, then true morphological intermediates might have
only been realized in larval forms. This, in turn, would explain the lack of
(adult) stratomorphic intermediates (interpreted as "transitional
forms" by evolutionists) in the fossil record. The divergence of
developmental pathways from a common ancestor in echinoderms (Sumrall 2000) is
an example. The absence of interclass and inter-order (adult) echinoderm
stratomorphic intermediates could be argued to be due to transitions occurring
in early developmental forms which are expressed in adults as abrupt and large
changes. On the other hand the multiple origin of echinoderm larval forms in
echinoderm genera (mentioned by Raff) and the multiple origin of developmental
pathways in echinoderm higher groups (mentioned by Sumrall) seems to make this
hypothesis highly unlikely.
Robert Carroll (2000) provided another more dramatic example
by showing the strong similarities between several fossil larval forms of the
extinct labyrinthodont amphibians (known as branchiosaurs) and modern
salamanders and frogs. Thus, although there are no adult stratomorphic (stratigraphic
and morphological) intermediates between labyrinthodonts and modern salamanders,
larval labyrinthodonts (branchiosaurs) function in that capacity. However,
mosaic combinations of salamander and frog morphologies among the branchiosaurs
make the actual identification of stratomorphic intermediates difficult. If
one assumes this scenario to be true, there are repeated convergences of the
direction of developmental ossification. Such convergences seem to render the
process improbable.
Yet another example was provided by Graham Budd and Joakim
Eriksson (2000). Lower Paleozoic arthropods have anterior mouthparts rather than
ventral mouthparts as in modern arthropods and onychophorans. Yet, onychophorans
begin development with anterior facing tissue which develops into mouthparts.
This suggests that the common ancestor had anterior mouthparts. This hypothesis
is attractive because several worm groups have anterior mouthparts and so can
function as an evolutionary ancestor. On the other hand, none of these groups
have the segmentation of the Onychophora and Arthropoda, suggesting that
segmentation and probably jointed appendages are convergent characters.
CLIMATOLOGY
Andrea Bair (2000) documented an increase in hypsodonty
(high-crowned teeth) and diversity among fossil lagomorphs (e.g., rabbits) in
the North American Miocene sediments. So, at about the same time and on the same
continent that horses (see MacFadden 1992) and camels and other mammalian
herbivores are (convergently) increasing in hypsodonty and diversity, rabbits
and pikas are doing the same. In fact, Bair claims hypsodonty arose 5 different
times in the pikas alone! Austin et al. (1994) suggested that the selection
pressure for hypsodonty is a consequence of the post-Flood spread of grasses at
the expense of broad-leafed plants during the cooling and drying period on the
post-Flood earth.
As the climate of the post-Flood earth converged on a modern
climatic regime, hot dry regions developed in the earth's low latitudes. The
likely drop in partial pressure of carbon dioxide through the Flood (Austin et
al. 1994) combined with the dry heat stress in low latitudes is likely to have
favored the spread of grasses with photosynthetic pathways adapted for tropical
(C4) and desert (CAM) environments.
This in turn is likely to have encouraged the proliferation of such grasses at
the expense of broad-leafed plants. In the Paleontological Short Course held on
the Sunday preceding the GSA meeting, Thure Cerling and J.R. Ehleringer
(2000) reported that ungulate teeth and fossil soils first pick up
carbon-isotopic evidence of C4 photosynthesis
in Miocene sediments. The oldest known fossil C4 plant
is also found in Miocene sediments. It is also in Miocene sediments that a
substantial increase in hypsodonty is found in a variety of herbivores. It may
be in the dry post-Flood times (during the brief period of deposition of Miocene
sediments) that C4 and CAM
photosynthesis arose and spread among the plants. Such alternate photosynthetic
pathways are now found in 15 different dicot families and 3 monocot
families, including about 5000 grass species (Cerling and Ehleringer 2000;
see also Wood [in review b] for more discussion). Such widespread and rapid
origin of complexity is better explained by Wood's (in review a) theory of
altruistic genetic elements (AGEing) than conventional evolutionary theory.
AGEing is also likely to be the mechanism for the simultaneous explosion in
diversity observed in lagomorphs (Bair 2000), horses (MacFadden 1992), and other
herbivorous animals.
ARCHAEOLOGY
Robert Schoch and John West (2000) gave an update of their
controversial research on the Egyptian Sphinx. Based on early Old Kingdom
repairs on the Sphinx and early Old Kingdom quarrying that diverted surface
water from eroding the Sphinx, the Sphinx is given a pre-dynastic age (Schoch
and West 1991). The water erosion of the Sphinx and other pre-dynastic
structures (including the core of the Dahshur Pyramid) suggests that
pre-dynastic Egyptian climate included high precipitation rates, as expected in
the post-Flood climate proposed by Michael Oard (1990) and modeled by Larry
Vardiman (1994). At the same time, the pre-dynastic date for the Sphinx suggests
a pre-dynastic date (and thus deeper time) for sophisticated culture in Egypt,
as would be expected of culture-capable people dispersing from the Tower of
Babel.
James Teller et al. (2000) proposed that Noah's Flood is to
be identified with the inundation of the Persian Gulf. Dunes in United Arab
Emirates are composed of carbonate grains derived from the floor of the Persian
Gulf at a time when the Gulf was water-free. Following formation of these dunes,
the Gulf was filled with water from the ocean — conventionally dated between
14,000 and 6,000 y.b.p. Teller et al. suggest that the sea level rise might have
exceeded 1 km per year at times — so fast as to require boats to rescue people
stranded on islands. Although geographically superior to recent proposed
identification of Noah's Flood with the flooding of the Black Sea (Ryan and
Pitman 1999), this explanation fails to explain a) the breaking up of the
fountains for the great deep (Gen. 7:11); b) unusual rain (e.g.,
"windows of heaven" vs. rain in Gen. 8:1); c) the great wind
(Gen. 8:1); d) the falling of the waters (e.g., Gen. 8:5); e) the covering
of all the high hills under the whole heaven (Gen. 7:19); f) the death of all
humans and animals on the face of the earth (e.g., Gen. 7:23); etc.
Stephen B. Mabee et al. (2000) reported early results on
research into the famous Nasca Lines of Peru. They reported on two locations
where ancient aquifers, habitations, and cemeteries are associated with fresh
water springs, which are in turn located along earthquake faults. In each case,
nearby Nasca Lines in the form of triangles actually point out the fault trace
as it extends across the desert towards the next pass and associated water
sources. The researchers are planning to test the hypothesis that the Nasca
Lines were constructed so that these people could find water in the desert of
Peru. This explanation is not only reasonable (vs., e.g., an alien origin a la
von Däniken
[1971]) but also suggests that the ancient Peruvians might have had some
geologic acumen, capable of creating hydrology and fault maps. This is
consistent with the biblical inference that humans have been intelligent and
capable of high culture from their origin.
REFERENCES
*Kurt P. Wise, P.O. Box 7585, Dayton, TN
37321-7000 USA; (423) 775-7252; wise@bryancore.org
**Arthur V. Chadwick, Southwestern Adventist University, Keene,
TX 76059 USA; (817) 645-3921 x277; chadwick@swau.edu
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Geoscience Research Institute. All rights reserved.
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