time to break down, and a time to build up ... A time to rend, and a time to sew: a
time to keep silence, and a time to speak." Evolutionary theory now stands in the
happier second state of these genuine dichotomies (in part because the first state
had been mined to the limited extent of its utility): we live in a time for building
up, for sewing together, and for speaking out.
Not all times are such good times, and not all scientists win the good fortune
to live within these times of motion. For theories grow as organisms do, with
periods of Sturm und Drang, long latencies of youth or ossifications of age, and
some happy times of optimally productive motion in between (another
Goldilockean phenomenon). I recently studied the life and career of E. Ray
Lankester (Gould, 1999a), clearly the most talented evolutionary morphologist of
the generation just after Darwin. He did "good" work and had a "good" career (see
Chapter 10, pages 1069-1076 for his best theoretical efforts), but he never
transcended the ordinary. Perhaps the limitation lay largely within his own
abilities. However, I rather suspect that he did possess both the temperamental
gumption and the requisite intellectual might—but that the tools of major empirical
advance just didn't emerge in his generation, for he remained stuck in a relatively
unproductive middle, as Darwin had seized the first-fruits from traditional data of
natural history, and the second plucking required a resolution of genetic
mechanisms.
I felt a similar kind of frustration in 1977, after writing my first technical
book, Ontogeny and Phylogeny (see Chapter 10, pages 1061-1063). I had spent the
best years of a young career on a subject that I knew to be relevant (at a time when
most of the profession had forgotten). But then defeat snatched my prize from the
jaws of victory. I am proud of the book, and I do believe that it helped to focus
interest on a subject that became doable soon thereafter. But I ran up against a wall
right at the end—for the genetics of development clearly held the key to any
rapprochement of embryology and evolution, and we knew effectively nothing
about eukaryotic regulation. Indeed, as we could then only characterize structural
genes by electrophoretic techniques, our major "arguments" for regulatory effects
(if they even merited such a positive designation) invoked such negative evidence
as the virtual identity in structural genes between chimps and humans, coupled
with a fair visceral sense of extensive phenotypic disparity in anatomy and
behavior— with the differences then attributed to regulatory genes that we could
not, at the time, either study or even identify.
By sheer good fortune (abetted in minuscule ways by my own pushes and
those of my paleontological colleagues), the field moved fast and I lived long
enough to witness a sea change (if I may cite Ariel yet again) towards potentiation
on all three major intellectual and social substrates for converting a subject from
great promise combined with even more frustrating inoperability, into a discipline
bursting with new (and often utterly surprising) data that led directly to testable
hypotheses about basic issues in the structure of evolutionary theory.
EMPIRICS. During the last third of the 20th century, new techniques and
conceptualizations opened up important sources of data that challenged or-
26 THE STRUCTURE OF EVOLUTIONARY THEORY