The Essence of Darwinism and the Basis of Modern Orthodoxy 111
(10) Taxonomic affinity of island endemics—perhaps the most obvious point
of all: why are the closest relatives of island endemics nearly always found on the
nearest continent or on other adjacent islands?
Any honorable creationist, after suffering such a combination of blows, all
implicating a history of evolution as the only sensible coordinating explanation,
should throw in the towel and, like a beaten prizefighter, acknowledge Darwin as
the Muhammad Ali of biology.
DISCORDANCE (DISSONANCE OF ONE). Consilience works as a cumulative
argument for inferring history from objects and phenomena, rather than directly
from sequences. You develop a line of attack, list numerous points, and then close
in for the kill. But the empirical world often fails to provide such a bounty of
evidence. Often, scientists must reason from a single object or situation—just the
thing itself, not a network of arguments suitable for a broad consilience. Can
history be inferred from such minimal information?
Thinkers, like soldiers, often show their true mettle in greatest adversity. I am
particularly attracted by Darwin's approach to method 4, and have often cited his
arguments in these "worst cases" as my primary illustration of his genius (Gould,
1986)—for Darwin met his greatest difficulty, and then not only devised a
resolution, but also developed an argument of power and range. In other words, he
turned potential trouble into one of his greatest strengths.
To infer history from a single object, Darwin asserts, one must locate features
(preferably several, so the argument may shade into method three) that make no
sense, or at least present striking anomalies, in the current life of the organism. One
must then show that these features did fit into a clearly inferable past environment.
In such cases, history—as expressed by preservation of signs from the past—
provides the only sensible explanation for modern quirks, imperfections, oddities,
and Anagenesis
Darwin structured the Origin of Species as a trilogy. The first four chapters
lay out the basic argument for natural selection. The middle five treat difficulties
with the theory, and ancillary subjects that must be incorporated or explained away
(rules of variation, nature of geological evidence, instincts, hybridism, and general
objections). The final five chapters present the grand consilience by summarizing
evidence for evolution itself—not so much for natural selection as a mechanism—
from a broad range of disparate fields: geology*, geographic variation,
morphology, taxonomy, embryology, and so forth.
The last part of the trilogy features method four. One might almost say that
chapters 10-14 constitute one long list of examples for inferring history
*This tripartite structure of the Origin is masked by our tendency to treat the two
geological chapters (9-10) as a unity. (Darwin even summarizes them together at the end
of Chapter 10.) But Chapter 9, as the title proclaims ("On the imperfection of the
geological record"), belongs to the discussion of difficulties in part 2 of the Origin—
while Chapter 10 ("On the geological succession of organic beings") initiates part three
on documentation of evolution as a fact. (Even the consolidated summary of Chapter 10
makes a clear break between these two disparate parts of Darwin's geological argument.)