with fewer) issue.
The average form moves slowly in the favored direction, bit by bit per generation,
through massive elimination of less favored forms.The process might not
be so inefficient if the hecatomb only occurred once at the beginning or if the
sacrifice diminished from generation to generation. Suppose, for example, that
the few survivors of the first hecatomb then automatically produced offspring
with tendencies to vary in the favored direction. But Mendelian inheritance doesn't
work this way. The few survivors of the first elimination yield offspring that
also vary at random about the new average. Thus, the hecatomb in the second generation,
and in all subsequent sortings, may be just as intense. We may
use an analogy to symbolize the inefficiency of natural selection by hecatomb.
Suppose that a population will be better adapted if it can move from A
to B. In direct Lamarckian models, including the only evolutionary scheme
that Paley managed to conceptualize, the movement is direct, purposeful, and positive.
Members of the population get a push and just walk from A to B.
In the clumsy, wasteful, blundering, low, and horribly cruel Darwinian hecatomb,
each individual stands at spot A and falls at random. Those that happen
to fall right along the line to B survive to the next trial. All individuals
who fall off the line--the vast majority--are summarily shot. After a
round of reproduction among the few survivors of this first hecatomb, the second
trial begins. Standing now at one body length along the path to B, all individuals
fall at random again--and the process continues. The hecatomb is equally pronounced
in each round, and the population moves but one body length toward its goal each
time. The population will eventually get to point B, but would any engineer favor
such a poky and punitive device? You can hardly blame the divine Paley for not
even imagining such a devilish mechanism. I do not contrast Darwin
with Paley as an abstract rhetorical device. During his youth, Darwin, as quoted
above, revered Paley. In a courageous act of intellectual parricide, he then overthrew
his previous mentor, not merely by becoming an evolutionist, but by constructing
a particular version of evolutionary theory maximally disruptive of Paley's system
and deepest beliefs. I can imagine two revolutionary ways--one
more radical than the other--to overturn Paley's comfortable and comforting
belief that God made us all with shapes and habits beautifully adapted to our
modes of life. You might argue that Paley was wrong, that animals are not generally
well designed, and that if you insist on seeing God's work in the massive imperfection
of nature, then perhaps you ought to revise your notion of divinity. This would
be a radical argument, but Darwin devised an even more disturbing version.
Secondly, you might argue (as Darwin actually did) that Paley was quite right:
animals arc well adapted to their modes of life. But this adaptation is not an
emblem of God's benevolence, good design, on the contrary, is an indirect result
of the horrid system of multiple hecatombs known as natural selection. What a
bitter pill for Paley--to admit that nature appears in His light, but then
to argue that the mechanism for this appearance has a mode of action, and an apparent
moral force, directly contrary to the intent and benevolence of the God of Natural
Theology. Where did Darwin get such a radical version of
evolution? Surely not from the birds and bees, the twigs and trees. Nature helped,
but intellectual revolutions must also have ideological bases. Scholars have debated
this question for more than a century, and our current "Darwin industry"
of historians has moved this old discussion toward a resolution. The sources were
many, various, and exceedingly complex. No two experts would present the same
list with the same rankings. But all would agree that two Scottish economists
of the generation just before Darwin played a dominant role: Thomas Malthus and
the great Adam Smith himself. From Malthus, Darwin received the key insight that
growth in population, if unchecked, will outrun any increase in the food supply.
A struggle for existence must therefore arise, leading by natural selection to
survival of the fittest (to cite all the conventional Darwinian aphorisms). Darwin
states that this insight from Malthus supplied the last piece that enabled him
to complete the theory of natural selection in 1838 (although he did not publish
his views for twenty-one years). Adam Smith's influence was more
indirect, but also more central and pervasive. We know that the Scottish economists
interested Darwin greatly and that during the crucial months of 1838, while he
assembled the pieces soon to be capped by his Malthusian insight, he was studying
the thought of Adam Smith. The theory of natural selection is uncannily similar
to the chief doctrine of laissez-faire economics. (In our academic jargon, we
would say that the two theories are isomorphic--that is, structurally similar
point for point, even though the subject matter differs.) To achieve the goal
of a maximally or- |