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Access Research Network
Literature Survey
Origins & Design 18:2
Paul Nelson
Fresh Light on the Cosmological
Argument
Robert C. Koons, "A New
Look at the Cosmological Argument," American Philosophical
Quarterly 34 (April 1997): 193-211.
Robert Koons (Philosophy, University of Texas, Austin) has
written a challenging reassessment of the cosmological argument,
and develops a critique of what he calls the "junky cosmos"
line of reasoning. "There is another serious drawback to
the junky cosmos hypothesis: if employed globally, it has the
consequence that any form of induction is demonstrably unreliable.
If we embrace the junky cosmos hypothesis to explain away every
appearance of orderedness in the universe, then we should assume
that the simplicity and regularity of natural law is also an artifact
of observer selection. Universes would be posited to exist with
every possible set of natural laws, however complex or inductively
ill-behaved. Now take any well-established scientific generalization.
Among the universes that agree with all of our observations up
to this point in time, the number that go on to break this generalization
is far greater than the number that continue to respect it. The
objective probability that every generalization we have observed
extends no farther than our observations is infinitely close to
one. Thus, relying on induction in such a universe is demonstrably
futile. In short, the junky cosmos hypothesis is both the most
flagrant possible violation of Occam's razor and a death sentence
to all other uses of that principle. This hypothesis postulates
an infinity of entities for which there is absolutely no positive
evidence, simply in order to avoid the necessity of explaining
the anthropic coincidences we have observed. This is the height
of metaphysical irresponsibility, far worse than the most extravagant
speculations of medieval angelology." return to top
Agassiz's Arguments
Against Darwinism
Paul J. Morris, "Louis
Agassiz's Arguments against Darwinism in His Additions to the
French Translation of the Essay on Classification," Journal
of the History of Biology 30 (1997): 121-134.
Louis Agassiz (1807-1873), the great Swiss-American fossil
fish systematist, geologist, and, in Stephen Jay Gould's words,
"America's leading biologist" of the mid-nineteenth
century, never accepted Darwinian evolution. Many commentators
have suggested that Agassiz's "species essentialism"
motivated his resistance, yet Paul Morris (Biology, University
of Massachusetts, Amherst) disagrees, arguing that "species
were neither the core nor an important focus of Agassiz's arguments
against Darwin."
Rather, as spelled out in a little-known 1869 publication,
Agassiz develops "three main arguments; (1) Darwinism is
an a priori doctrine that selectively interprets facts, rather
than being induced from them. (2) Variation is a universal characteristic
of organisms but has distinct limits: it exists only in individual
peculiarities; never do species-level characters vary, nor do
those characters that distinguish genera, families, orders, classes,
or branches. (3) The fossil record is, in several ways, not consistent
with the expectations of progressive evolutionary change expounded
by Haeckel" (p. 126). Agassiz's arguments, Morris judges,
are "clearly not the statement of an ambivalent scientist
unwilling to take a stand on the issue of Darwinian evolution,"
but instead "the statement of a naturalist who was certain
that the evidence of nature firmly supported his own worldview"
(p. 133). Thus, in contrast to the usual picture of Agassiz as
a religiously-motivated reactionary, Morris suggests "it
should be abundantly clear that Agassiz's opposition to Darwinism
was based in a cogent worldview, and that the core of his opposition
lay in a literal, empirical interpretation of the natural world,
especially the fossil record. Agassiz's arguments are clearly
not a dogmatic argument based in religion, but are firmly based
in the data of portions of the natural world that the Darwinian
of the late 1800s was ill able to explain" (p. 133). return to top
The Relationships
of Whales: Molecules or Morphology?
Michel C. Milinkovitch, "Molecular
phylogeny of cetaceans prompts revision of morphological transformations,"
Trends in Ecology and Evolution 10 (August 1995): 328-334.
Masami Hasegawa, Jun Adachi,
Michel C. Milinkovitch, "Novel Phylogeny of Whales Supported
by Total Molecular Evidence," Journal of Molecular Evolution
44 (Supplement 1, 1997): S117-S120.
That molecular evidence typically squares with morphological
patterns is a view held by many biologists, but interestingly,
by relatively few systematists. Most of the latter know that the
two lines of evidence may often be incongruent. A recent case
in point concerns the hypothesized evolution of whales. According
to standard or "classical" classifications, all the
toothed whales, the Odontoceti, share a more recent common ancestor
than the baleen whales, the Mysticeti. But, in a provocative new
theory advanced primarily by Michel Milinkovitch of the University
of Brussels, anatomical evidence -- the teeth and single blow
holes of toothed whales -- as well as behavioral evidence
(echolation) is misleading. In fact, Milinkovitch writes, "evolutionary
relationships among the major groups of cetaceans is more problematic
since morphological and molecular analyses reach very different
conclusions. Indeed, based on the conventional interpretation
of the morphological and behavioral data set, the echolocating
toothed whales (about 67 species) and the filter-feeding baleen
whales (10 species) are considered as two distinct monophyletic
groups. ...On the other hand, phylogenetic analysis of DNA ...
and amino acid ... sequences contradict this long-accepted taxonomic
division. One group of toothed whales, the sperm whales, appear
to be more closely related to the morphologically highly divergent
baleen whales than to other odontocetes." return to top
The Junk Dealer
Ain't Selling That No More
Emile Zuckerkandl, "Neutral
and Nonneutral Mutations: The Creative Mix--Evolution of Complexity
in Gene Interaction Systems,' Journal of Molecular Evolution 44
(1997): S2-S8.
Peter E. Warburton and David
Kipling, "Providing a little stability," Nature 386
(10 April 1997): 553-555.
Hubert Renauld and Susan M. Gasser, "Heterochromatin: a meiotic
matchmaker," Trends in Cell Biology 7 (May 1997): 201-205.
In one of his later books, written with his wife Ann Druyan
(Shadows of Forgotten Ancestors, Ballantine, 1992), the late Carl
Sagan argued that "genetic junk," the "redundancies,
stutters, [and] untranscribable nonsense" in DNA, proved
that there are "deep imperfections at the heart of life"
(p. 128). Such comments are commonplace in the biological literature
-- although perhaps less common than they were a few years
ago. The reason? Geneticists are discovering functions for what
used to be apparent genetic debris.
Take heterochromatin: the highly repetitive DNA coding for
few, or no, proteins. "Despite its significant representation
in the genome," Renauld and Gasser (Swiss Institute for Experimental
Cancer Research) write, "(up to 15% in human cells and ~30%
in flies), heterochromatin has often been considered as 'junk'
DNA -- that is, DNA without utility to the cell" (p.
201). However, recent studies suggest that heterochromatin may
play important functional roles; biologists have been looking
at the wrong level. As Emile Zuckerkandl (Institute of Molecular
Medical Sciences) observes,
Interestingly ... if one adds together nucleotides [DNA base
pairs] that are individually nonfunctional, one may end up with
a sum of nucleotides that are collectively functional. Nucleotides
belonging to chromatin are an example. Despite all arguments
made in the past in favor of considering heterochromatin as junk,
many people active in the field no longer doubt that it plays
functional roles. ...Just as, quite some time ago, populational
thinking became a necessity in genetics, we need now to get used
to populational thinking in regard to the function of nucleotides.
They may individually be junk, and collectively, gold. (p. 53)
One such "collective" function may occur in meiotic
pairing. Also, studies of artificial chromosomes have demonstrated
other functions:
The minimal requirements for an artificial chromosome include
sequences to allow for the maintenance of its ends (telomeres),
replication of its DNA, and mitotic segregation to daughter cells
(centromeres). ...The centromere is not simply a passive point
at which the chromosome attaches to the microtubules of the mitotic
spindle -- it actively participates in the segregation of
chromosomes to daughter cells. The centromeric region contains
at least one motor, which is involved in chromosome movement
during cell division. The centromere also mediates a critical
checkpoint that prevents completion of cell division until all
chromosomes are properly attached to the mitotic spindle.
return to top
Copyright © 1997 Paul Nelson. All rights
reserved. International copyright secured.
File Date: 1.1.98
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