INSIDE THE HUMAN GENOME: A Case for Non-Intelligent Design by John
C. Avise. New York: Oxford University Press, 2010. 222 pages including
notes, glossary, index. Hardcover; $19.95. ISBN: 9780195393439.
Many of the readers of PSCF have heard this interesting story: a
Harvard student sits in the office of the chaplain and confesses that he
just does not believe in God. The chaplain responds, "Well, tell me
about this God you don't believe in. I probably don't believe
in him either." The veracity of the tale is dubious, but its lesson
is centrally important, whether one is considering aspects of the divine
or merely contemplating a challenging new idea. Which god are we
confessing or rejecting or blaspheming? Which theory are we addressing
or debunking? With whom are we agreeing or disagreeing? Readers of this
book would do well to keep such questions before them as they consider
Avise's ideas, which vary from the profound to the pedestrian,
depending on the target of analysis.
Avise's project is twofold. His goals, spelled out repeatedly
throughout the concise but frequently redundant text, can be discerned
from this characteristically blunt remark on page 65, in a section
entitled "Errors and Forgiveness":
Avise's first goal is to detail the myriad ways in which the
human genome--in function and in architecture--is an exemplar, not of
intelligent design, but of its apparent opposite: a "Byzantine
contrivance" with features that were "accumulated stepwise by
sloppy tinkering forces" (p. 74). Mere proneness to occasional
disastrous mutation would not establish that conclusion, but Avise takes
his case much further and to greater effect, pointing to fundamental
features of the organization of the human genome that encourage and even
facilitate dysfunction on various scales.
One full chapter examines various aspects of genomic complexity,
ending with a focus on the peculiar fact that many of the genes
controlling mitochondrial function are housed in the mitochondria
themselves. This arrangement is inefficient and fraught with danger
(genetic material is housed next to a prolific generator of mutagenic
reactive oxygen species), and Avise labels it "downright
ludicrous." He notes that common descent nicely explains this
design, but his chief aim is not to promote evolutionary explanation. It
is to point out "logical problems" with the argument that
genomes evince design by a wise and benevolent "supreme
intelligence."
Another chapter describes the multitudinous repetitive elements
that characterize the human genome, including hundreds of thousands of
mobile elements that account for fully one third of every person's
genetic endowment. These elements wreak havoc in several ways, causing
malfunctions via effects ranging from subtle alterations in gene
expression to catastrophic destabilization of whole chromosomal regions.
Avise adds that many of these effects probably remain unaccounted for:
mobile elements are particularly active in germ cells, and their action
is expected to kill embryos very early in development. He notes that
some mobile DNA elements have apparently been put to good use during
evolution, but concludes that their huge numbers result in a genome that
is "grotesquely infested with parasitic elements" (p. 130).
Importantly, Avise asserts that the disorders arising from such features
of the human genome are not merely "aberrations from a genetic
blueprint of optimal design" (p. 127). They are outcomes to be
expected in the presence of that grotesque infestation.
And so it goes. Avise's case is very strong. The human genome
does seem to me to be a "genomic jungle" and a "Byzantine
contrivance." Its imperfections are legion, and they are caused by
"universal architectural flaws." These failures cannot be
dismissed as minor glitches that have marred an initially perfect
creation, nor can they be effectively described as necessary precursors
to--or byproducts of--designed features or necessary functions. Avise
concludes that "inevitable imperfection" is better established
than irreducible complexity.
These challenges to intelligent design thought, along with some
clear and well-written descriptions of evolutionary theory, are the
strongest contributions of the book, and make it a worthwhile read for
those interested in questions of design and optimization in biology. But
do Avise's challenges refute, or weaken, design arguments? Surely
the book undermines any rosy story of a benevolent designer carefully
crafting a masterwork of exquisite design, but that is a caricature of
many of today's design proposals. Avise is fair on this point,
claiming mostly to shift attention onto flaws and evident failures of
design and focusing on the concept of a loving and omnipotent God as the
Designer. Nevertheless, the book should not be taken as a new or
particularly effective rebuttal to typical claims of intelligent design
theorists.
Avise's second project, however, is less successful and less
valuable. Having shown that the human genome's deep flaws lead to
widespread suffering and death, he moves to conclude that this fact
brings some significant resolution to Christianity's struggle with
the problem of evil, arguing (as have Francisco Ayala and others before
him) that "evolution by natural causes emancipates religion from
the shackles of theodicy" (p. 157). How does evolution accomplish
this? On page 158, he answers,
This reasoning will strike many readers of PSCF as basically
flawed. While some may agree that natural causation rules out the work
of God's "direct hand," the suggestion that this shifts
responsibility away from him completely, does not follow. After all, one
need not wield a weapon with one's own hands to be held culpable
for a crime. I suspect that most Christians would agree with me that
there is little if any distinction between causing pain and standing by
while it is caused by someone or something else. Blame-shifting just
does not help: once we confess an omnipotent deity with the means to
intervene, we put that deity right back on the hot seat of theodicy.
Perhaps Avise has a different god in mind when he seeks to absolve the
divine. In any case, assessing his success requires identifying this god
a priori.
Avise has argued successfully against the proposal that the human
genome is an example of excellent design, or even a product of a little
bit of optimization, and his case is worth examining. And while his
attempt to bring some peace to the struggles between evolution and some
sectors of Christendom is a decent thing, few of us would have thought
that the problem of evil could be so easily dispatched.
Reviewed by Stephen F. Matheson, Associate Professor of Biology,
Calvin College, Grand Rapids, MI 49546.
A proverbial sentiment is that "To err is human, to
forgive is divine." If the kinds of harmful mutations
described above are to be attributed to an intelligent
and otherwise revered agent (i.e., an omnipotent
deity), then the popular phrase needs revision: "to err
is divine, to forgive is human." Few people would
blame a loving and all-powerful God for purposefully
inventing deleterious mutations; that would be
blasphemous.
No longer need we blame a Creator God's direct
hand for any of these disturbing empirical facts.
Instead, we can put the blame squarely on the agency
of insentient, natural evolutionary causation.