About five years ago I took a course in human evolution. At one of the
classes we were introduced to P. G. Williamson who worked under Richard
Leakey in Kenya. When Williamson was first assigned, he naturally wanted
to set out on the trail of those incredible hominids. Leakey had other
ideas.
Leakey believes it was the "Gregory Rift" that runs for 3,000 miles from
Israel to Mozambique, that formed about 15 million years ago, and led
directly to the ape/man split, resulting in you and me (or me and some
of you, as we do have some on this forum who think they were the product
of special creation).
The Gregory Rift was, according to Leakey:
"A geological episode of unimaginable proportions,
the formation of the rift played a vital role in the
evolution of our species. In fact, it is possible that
had the Gregory Rift not formed when and where it
did, the human species might not have evolved at
all--ever." 1
In his classroom lecture, Williamson expressed his disappointment at being
given what he considered to be a mundane task. But what Leakey wanted was
independent confirmation that the rift valley contributed to the
evolutionary development of more than primate bipedalism. If his theory
was correct, other creatures should have been similarly affected by the
sudden change in environment, and specifically the mollusks in the Turkana
Basin in East Africa
Williamson dutifully set about the task and reported the results in the
British journal _Nature_. In an article titled "Palaeontological
documentation of speciation in Cenozoic molluscs from Turkana Basin,"
Williamson declared in the abstract:
"Evolutionary patterns in all lineages conform to the
'punctuated equilibrium' model; no 'gradualistic'
morphological trends occur." 2
Williamson tracked 13 lineages of fossil mollusks, including ten which
could be followed for 4-5 million years, with change concentrated in short
(5,000-50,000 years) speciation events, between long periods (3-5 million
years) of morphological stasis.
Moreover, Williamson correlated rapid speciation with an environmental
event, the evaporating Lake Turkana brought about by resulting drought
after the great rift divided the continent.
In a section titled "Implications," Williamson stated:
"A persistent problem in evolutionary biology has
been the absence of intermediate forms in the fossil
record. Long-term gradual transformations of single
lineages are rare and generally involve simple size
increases or trivial phenotypic effects. Typically, the
record consists of successive ancestor-descendant
lineages, morphologically invariant through time and
unconnected by intermediates ... but in small, stressed,
geographically isolated populations, homeostatic
mechanisms break down during 'genetic revolution'
and rapid evolution may ensue."
"The phylogenetic geometry of molluscan lineages
from the Turkana Basin sequence clearly conforms to
the punctuated equilibrium model; long-term stasis in
all lineages is punctuated by rapid episodes of major
phenotypic change. No 'gradualistic' morphological
trends occur in any lineage."
At the end of the article Williamson concluded:
"Apart from the tantalizing insights into speciation
mechanisms offered by the Turkana Basin sequence,
it has two more general implications for evolutionary
theory. The documented restriction of significant
evolutionary change to speciation events indicates that
the underlying unit of macroevolutionary change is the
species. The fact that evolutionary change at the species
level is shown to be punctuated and achieved by
'revolutionary' periods of extreme developmental
instability strongly supports the notion that speciation
is a qualitatively different phenomenon from gradual,
intraspecific microevolutionary change."
Williamson's method of "doing science" consisted of collecting some 3,300
individuals with meticulous measurement, accompanied by sound conclusions
based on hard evidence. It is troubling when you contrast this kind of
work from a secular scientist with the "conclusions by innuendo" method
employed by Christian young-earth and progressive creationists who declare
that the interconnected inner-workings of organisms are so wonderful that
God must have intervened in sporadic episodes of special creation at every
instance of speciation throughout the entire history of organisms on planet
Earth.
And where is the evidence to support this hypothesis? Just a litany of
wonderful, biological, interconnected, inner-workings. It may impress the
scientifically challenged, but it sounds just like the bombast masquerading
as data that has been emblematic of creationist literature in general. If
they can't do any better than that, they should withdraw diplomatically and
crawl into one dark corner of "Darwin's Black Box."
NOTES:
1. Richard Leakey & Roger Lewin, _Origins Reconsidered_ (New
York: Doubleday, 1992), 9.
2. P. G. Williamson, _Nature_ 293, 437 (1981).
Dick Fischer
THE ORIGINS SOLUTION
http://www.orisol.com