The Fruitful Facets of Galton's Polyhedron 381
selection of but four out of the varieties of PL levis, and the continuous
propagation and increasing intensity of the differences which they exhibit.
An examination... will show anyone how many variations are lost in each
form or species of the series, and how few are continued. This can only be
accounted for upon the supposition that those which survived possessed in
some way advantages indicated by their peculiar variations, which enable
them to propagate those variations, and suppress their less fortunate
neighbours (1880, p. 26).But how shall we explain the far more important issue of causes for actual
directions of modification in the lineages—that is, the evolutionary changes
themselves? Hyatt asks whether selection could be effective here: "Are these
parallelisms adaptations, and can they possibly be attributed to the direct action of
the uniform external environment upon the forms of the different series?" (1880, p.
19). Hyatt denies any formative power to the Darwinian mechanism. Selection can
do the negative work of weeding and separating, but cannot perform the positive
action—the essence of evolution—of changing and progressing.
Hyatt offers two major critiques of selection in the light of ontogenetically
programmed orthogenesis. First, how can the functional premise of adaptation be
supported when so much change occurs in the regressive mode following phyletic
maturity? "Nothing can exceed the confidence with which the strict Darwinist
assumes, without any appeal to observation, that all characteristics which are
inherited are necessarily advantageous. Exactly the reverse is very often true"
(1880, p. 101). Second, he recognizes that Darwin's system entails a crucial
assumption of isotropic, undirected variability. Since the conveyor belt of the
grand potential ontogeny introduces new characters with a decided bias, creativity
resides in the internal directionality of variation. Natural selection can only work as
a subsidiary force to the primary agent of directed variation. "Natural selection, in
fact, is simply one of the transient conditions of the physical surroundings, having
no value as a cause of origin of characteristics" (1880, p. 102). The ontogenetic
conveyor belt feeds new characters and creates evolutionary novelty; selection can
only eliminate, separate and impose a little cosmetic shaping upon the internally
generated trend:
Thus it may be said that the struggle for existence, and the survival of the
fittest, is a secondary law grafted upon laws of growth, and governed by
them in all its manifestations. The law of natural selection, as generally
understood, assumes in the first place the existence of an animal type, of its
descendants, and of a tendency to variation (indefinite and unlimited) in
every one and all of these descendants, from which (an indefinite and
unlimited) selection may take place during the struggle for existence
between competing forms, destroying the weak and permitting only the
strongest and fittest of these variations to survive. The truth is, as far as my
studies have gone, that there is no such thing as indefinite or unlimited
variations in any species... This obvious proposition, if admitted,