354 THE STRUCTURE OF EVOLUTIONARY THEORY
as auxiliary—not consonant to be sure (for the nonselectionist logic cannot be
contravened)—but supplementary rather than substitutional. Thus, for example, if
acquired characters are inherited only rarely and weakly, then Lamarckism might
aid natural selection in developing adaptation more quickly (by secondary
reinforcement from a different source)—a position advocated by Darwin himself
throughout the Origin (1859, pp. 134-139, for example). But if acquired characters
are inherited faithfully all the time, then natural selection will be overwhelmed and
Lamarckism becomes a refutation of Darwinism. Relative frequency determines
the distinction. Kellogg writes, in a statement just before the quotation of the last
paragraph (1907, p. 262): "Few biologists would hold any of these theories to be
exclusively alternative with natural selection; de Vries himself would restrict
natural selection but little in its large and effective control or determination of the
general course of descent."
A similar situation prevails for orthogenesis. In Hyatt's "hard" (and truly
antiselectionist) version, the internal pathway dominates all lineages, literally
pushing the impotent force of natural selection aside, and forcing lineages to
extinction by phyletic senility. Natural selection exists as a "true" force, but can
only operate as a peripheral factor that can, at most, delay the inevitable. In milder
versions, the relative frequencies equalize (and the orthogenetic pathways need not
lead so clearly to inadaptive forms). In soft versions, still defendable today (though
we have ceased, for good reasons, to use the term "orthogenesis"), such internal
drives become auxiliaries to selection in providing an initial boost of directed
variation for the "incipient stages" of useful structures that posed so many
problems for early Darwinians (see Mivart, 1871)—and then letting the ultimately
more powerful force of natural selection prevail in the larger realm of evident
utility. Kellogg writes of such potentially "friendly" versions for Darwinism:
In true orthogenesis the variation, and hence the lines of modification, are
predetermined. It seems obvious, however, to any believer in natural
selection that sooner or later the fate of these lines of development will
come into the hands of selection. And most orthogeneticists do indeed
admit this. But it is precisely in the making of a start in modification that
orthogenesis fills a long-felt want, and if capable of proof, should be gladly
received by Darwinians as an important auxiliary theory in the explanation
of modification, species-forming, and descent [my italics, and an interesting
choice of words since Kellogg classifies orthogenesis as an alternative but
recognizes here that a sufficiently mild version would fall into his other
category of auxiliaries to Darwinism] (1907, p. 276).None of the three versions discussed below presents quite so mild a view
(though C. O. Whitman approaches such a formulation). All three conceive
orthogenesis as a competitor to Darwinism and a more powerful force than natural
selection. But these versions do illustrate a spectrum from the "centrist" Eimer (the
primary popularizer of the name and idea), who viewed natural