The Modern Synthesis as a Limited Consensus 549
behavior have their origin ... Putting the situation the other way around, a
society can be denned for our purposes as an organization capable of
providing conventional competition: this, at least, appears to be its original,
most primitive function, which indeed survives more or less thinly veiled
even in the civilized societies of man (1962, p. 14).Almost all the rich repertoire of putative Darwinian behaviors become, for
Wynne-Edwards, devices evolved by groups of organisms to limit their population
size. Dominance hierarchies and pecking orders become group-selected controls,
exercised by denying reproductive rights to large numbers of potential breeders.
The chorusing of frogs, insects and birds become censusing devices, whereby
populations may judge their numbers and trigger appropriate behaviors of
regulation.
Such homeostatic adaptations exist in astonishing profusion and diversity,
above all in the two great phyla of arthropods and vertebrates. There we
shall find machinery for regulating the reproductive output or recruitment
rate of the population in a dozen different ways—by varying the quota of
breeders, the number of eggs, the resorption of embryos, survival of the
newborn and so on; for accelerating or retarding growth-rate and maturity;
for limiting the density of colonization or settlement of the habitat; for
ejecting surplus members of the population, and even for encompassing
their deaths in some cases in order to retrieve the correct balance between
population-density and resources (1962, p. 9).Such massive suppression of the Darwinian game could only be achieved by
group selection—that is, by the differential success of groups with emergent social
behaviors that debar reproduction for many members, thus limiting population size
from within, and winning temporal persistence by avoiding collapse through
overexploitation: "We have met already with a number of situations—and shall
later meet many more—in which the interests of the individual are actually
submerged or subordinated to those of the community as a whole" (1962, p. 18).
Wynne-Edwards surely understood the stringent requirements for such a
mechanism. He recognized, for example, that demes or social groups must be
persistent and genealogically exclusive in order to act as higher-level "individuals"
in a selective process—as in this epitome of his views on group selection (1962, p.
144).
To understand group-selection we ought first to recognize that normally
local populations are largely of common descent, self-perpetuating and
potentially immortal. They are the smallest subdivisions of the species of
which this is true, and can be adapted to safeguard their own future. What is
actually passed from parent to offspring is the mechanism for responding
correctly in the interests of the group in a wide range of circumstances.
What is at stake is whether the group itself can survive or will become
extinct. If its social adaptations prove inadequate, the stock will decline or
disappear and its ground be colonized by neighboring