The Genetic Gods: Evolution and Belief in Human Affairs

288 Pages·1998·1.41 MB·English

by  John C. Avise

The Genetic Gods
Copyright © 1998 The President and Fellows of Harvard College
Copyright © 1998 The President and Fellows of Harvard College
The Genetic Gods
Evolution and Belief in Human Affairs
John C. Avise
Harvard University Press
Cambridge, Massachusetts and London, England, 1998
Copyright © 1998 The President and Fellows of Harvard College
Copyright © 1998 by the President and Fellows
of Harvard College
All rights reserved
Printed in the United States of America
Permission has been granted by the publisher to quote from Old Turtle by Douglas Wood
(Duluth, Minn.: Pfeifer-Hamilton Publishers, 1992).
Library of Congress Cataloging-in-Publication Data
Avise, John C.
The genetic gods : evolution and belief in human affairs / John C. Avise.
p. cm.
Includes bibliographical references and index.
ISBN 0-674-34625-4 (cloth : alk. paper)
1. Genetics—Popular works.
2. Evolutionary genetics—Popular works.
I. Title.
QH437.A95 1998
576—dc21 98-3255
Copyright © 1998 The President and Fellows of Harvard College
Contents
Preface vi
Prologue 1
1 The Doctrines of Biological Science 3
2 Geneses 22
3 Genetic Maladies 52
4 Genetic Beneªcence 81
5 Strategies of the Genes 106
6 Genetic Sovereignty 139
7 New Lords of Our Genes? 171
8 Meaning 203
Epilogue 218
Notes 221
Glossary 261
Index 275
Copyright © 1998 The President and Fellows of Harvard College
Preface
T
his book is intended for the reºective, open-minded reader
who would appreciate a simpliªed discussion of recent evolu-
tionary-genetic ªndings. Human beings, like all other species
on earth, are biological products of evolutionary processes, and as
such are physical expressions of genes, the “genetic gods.” Genes
and the mechanistic evolutionary forces that have sculpted them
thus assume many of the roles in human affairs traditionally re-
served for supernatural deities. Some may ªnd this argument blas-
phemous or sacrilegious; others may ªnd it prosaic. Such
contradictory responses reºect the paradoxical state of philosophi-
cal affairs, in which religious revelation and scientiªc rational-
ism uncomfortably coexist as powerful but opposing means of
knowing.
During the development of an individual, genes inºuence not
only bodily features at microscopic and macroscopic levels and the
metabolic and physiologic conditions underlying medical health,
but also the more ethereal aspects of human nature, including
emotions, psychologies, personalities, and even ethical and relig-
ious predilections. These genetic inºuences often are indirect,
mediated and modulated by diverse social and cultural experiences,
and manifest through genetically based cognitive abilities unique
to our species. Even the most sacrosanct of human affairs, sexual
reproduction and death, are products of evolutionary processes,
ªrmly ensconced in our genes.
The sciences of evolutionary biology and genetics, with roots
little more than a century deep, have blossomed in recent decades
to provide mechanistic understandings of human conditions that
until recently had been within the exclusive purview of mythol-
ogy, theology, and religion. Yet most people remain either bliss-
Copyright © 1998 The President and Fellows of Harvard College
PREF AC E vii
fully ignorant of these discoveries or openly hostile to their impli-
cations. As a practicing evolutionary biologist, I live in two worlds.
I work in a university setting surrounded by the astonishing pieces
of laboratory equipment and biochemical tools of molecular ge-
netics, and by reams of computer output on DNA sequences and
evolutionary-genetic simulations. My colleagues and graduate stu-
dents take for granted that natural forces have shaped the biological
objects of our studies (in my case, mostly ªshes, reptiles, and birds),
and research grants fund us to work out the genetic mechanisms
and processes by which these evolutionary outcomes have been
achieved. Yet when I return home to read the local newspaper, I
ªnd editorials lashing out against evolutionary biology in the name
of religion, and reports of school boards mandating equal time for
creationism in the science classroom. On TV and radio, evangelists
prohibit any departure from the word of God as they hear it.
Almost as disturbing are the technocrats or laboratory researchers
who naively proclaim that science and technology alone can pro-
vide certain salvation from humanity’s ills and all the world’s
problems.
This is a book about causation in biology. It makes no pretense
to wrestle seriously with the theistic ramiªcations of evolution
from the perspectives of religious philosophers or theologians, who
also have dealt with such issues extensively.1 However, a clearer
understanding of recent empirical ªndings in human molecular
genetics and conceptual advances in evolutionary-genetic theory
may increase communication between the social and the natural
sciences, and between theology and evolutionary biology. I hope
to diminish the hostility between these differing epistemological
approaches, which at their best do share a goal of attempting to
understand human nature.
Beyond these immediate aims, I hope to resolve a central issue
in my own life: how to reconcile the intellectual demands and
pleasures of critical scientiªc thought with the sense of purpose and
fulªllment that a rich spiritual life can provide. I subscribe to the
proposition that scientiªc rationalism is the surest route to objec-
tive understanding available to mortal humans, but I hold no
illusions that the pursuit of objective reality is necessarily satisfying.
This book champions science as the preferred path of rational
Copyright © 1998 The President and Fellows of Harvard College
viii PREF AC E
inquiry, but it makes no deªnitive claims regarding either the
ethical or the pragmatic value of rational objectivity itself.
I wish to thank Francisco Ayala, Betty Jean Craig, Douglas
Futuyma, Mike Goodisman, Matt Hare, Glenn Johns, Adam Jones,
Bill Nelson, Guillermo Ortí, Paulo Prodöhl, Daniel Promislow,
DeEtte Walker, Janet Westpheling, Kurt Wollenberg, and several
anonymous reviewers for critical comments on various drafts of
this manuscript. Through their conscientious efforts, I have gained
a deeper appreciation for the great diversity of thoughtful opinions
regarding evolutionary causation. I would also like to thank my
editors Michael Fisher and Kate Brick at Harvard University Press
for encouragement and excellent support.
Copyright © 1998 The President and Fellows of Harvard College
Prologue
I
n one of my favorite Star Trek episodes, the crew of the USS
Enterprise is sent to intercept an unknown object rapidly ap-
proaching Earth from deep space. As the story unfolds, the entity
reveals itself as “VGER” (pronounced veejer), and announces its
intent: to ªnd its creator on the third planet of our solar system.
VGER proves to be the long-lost Voyager 6 spacecraft, launched
from Earth three centuries earlier, and programmed to explore the
universe. Despite having amassed vast scientiªc knowledge on its
fact-ªnding journey, VGER’s computer systems nonetheless re-
main unfulªlled, and the space module now feels compelled to
discover its maker. The unsuspecting VGER is aghast and cha-
grined to learn that mere humans (“carbon-based units”) are its
gods.
Of course, VGER had discovered merely its proximate makers.
Humans must have their own creator. For thousands of years, we
too have been in search of deities through the emotional experi-
ences and exercises of faith that characterize mythologies and
traditional religious practices. Only in the last two centuries have
we begun an alternative, scientiªc approach to the exploration of
our biotic origins. Like the Star Trek Vulcans, whose emotionless
logic contrasts with the cultivated ardor of many religious practi-
tioners and theologians, scientists operate under the principle that
explanations for natural phenomena should be sought using obser-
vations and hypotheses divorced from emotive appeals, subjective
or personal impressions, or untestable dogma. Science and blind
faith are essentially at odds. Yet, like StarTrek’s Spock (whose
father was a Vulcan, mother a human), individual scientists ªnd it
impossible in practice to divorce their thoughts and ªndings from
social context, or from emotional or religious experiences, and I’m
quite certain most of them wouldn’t wish to do so.
1
Copyright © 1998 The President and Fellows of Harvard College