Pattern and Progress on the Geological Stage 477
sentiment, felt by many paleontologists, that organization on the whole has
progressed" (p. 345).
Sequelae
The central importance to Darwin of a link between progress and biotic
competition seems especially clear in the various ramifications that branch so
richly from his basic proposition. All these sequelae point to certain "smoothness,"
a form of predictability, an accumulation through time of the reasonable and little
into the sensible and big. Nature is not capricious; superior forms prevail for cause;
their triumph breeds further success and wider expansion; change proceeds in an
orderly fashion—not in a clocklike manner to be sure, but at least decorously.
Widespread and speciose genera usually include the ancestral stocks of later
successes, for extended geographic ranges and large populations indicate triumph
in competition, and good mettle for future progress: "The great and flourishing
genera both of plants and animals, which now play so important a part in nature,
thus viewed become doubly interesting, for they include the ancestors of future
conquering races. In the great scheme of nature, to that which has much, much will
be given" (Natural Selection, 1856 - 1858, 1975 edition, edited by Stauffer, p. 248).
If brought into competition after previous isolation, big clades from large
regions will prevail over less speciose groups from smaller areas because their
members have been tested in hotter fires of competition: "For in the larger country
there will have existed more individuals, and more diversified forms, and the
competition will have been severer, and thus the standard of perfection will have
been rendered higher" (p. 206). Thus the success of North American mammals in
South America following the rise of the Isthmus of Panama "is due to the greater
extent of land in the north, and to the northern forms having existed in their own
homes in greater numbers, and having consequently been advanced through natural
selection and competition to a higher stage of perfection or dominating power, than
the southern forms" (p. 379). In a revealing metaphor, Darwin then praises "the
larger areas and more efficient workshops of the north" (p. 380).
Looking at the complementary theme of failure, aberrant genera include few
species because such creatures have been beaten by superior forms in competition
(and not for a variety of other potential reasons including limited speciation, or
specialization to rare and unusual environments): "Such richness in species, as I
find after some investigation, does not commonly fall to the lot of aberrant genera.
We can, I think, account for this fact only by looking at aberrant forms as failing
groups conquered by more successful competitors, with a few members preserved
by some unusual coincidence of favorable circumstances" (p. 429).
Since competition will be ubiquitous, efficient, and unrelenting in a crowded
world, steady change should represent a norm, while stasis must record the unusual
circumstance of reduced competition—as in the "living fossils" explicitly dubbed
"anomalous" by Darwin: "These anomalous forms