Continental Drift: Not Even Wrong - Four Revolutions in the Earth Sciences - page 88

The topic ended with words of caution. To go beyond his outline of convection
as a mechanism “would at present be unwise,” Holmes wrote. “Purely speculative
ideas, specially invented to match the requirements, can have no scientific value
until they acquire support from independent evidence” (508). And finally: “Many
generations of work, geological, experimental, and mathematical, may well be ne-
cessary before the hypothesis can be adequately tested” (509).
On December 28-29, 1949, the American Museum of Natural History in New
York convened a symposium on “The Role of the South Atlantic Basin in Biogeo-
graphy and Evolution.” Ernst Mayr, curator of birds at the AMNH, chaired the
meeting. Two men from Columbia University whom we will meet again attended:
Walter Bucher (1888-1965) and Maurice Ewing (1906-1974). Bucher had written
in 1924 that “extensive displacement of the earth's crust has been limited to well-
defined “mobile belts, which are virtually continuous.” 26 In other words, the con-
tinents themselves had not moved. In a 1933 topic, The Deformation of the Earth's
Crust , he concluded the section on continental drift by writing: “The mechanism
of crustal folding furnished by the hypothesis of continental drift [is not] adequate
to account for the actual distribution of folded belts.” 27
In his article in the 1949 symposium volume, Bucher remained opposed to drift:
“The concept of continental drift,” he wrote, “cannot be used as a working hypo-
thesis by the student of animal and plant distribution.” Like Willis, Bucher urged
geologists to forget continental drift: “The student must get along without assum-
ing either that vast continental areas have foundered to form large areas of the
ocean floor, or that continents and islands have drifted” (101-102).
Ewing, Bucher's Columbia colleague, assessed the geophysical evidence. He
lumped together drift and land bridges and rejected both, preferring the notion of
permanent continents: “The hypothesis of the permanence of continents and ocean
basins fits the existing [geophysical] data best. There are strong indications against
the hypotheses of continental drift and foundered land bridges in the deep ocean
basins.” 28
In a 1952 report in Nature , Arthur Holmes reviewed the publication that grew
out of the AMNH symposium. 29 The sense that emerges from the topic and from
Holmes's review is that the majority of the participants saw no need for a connec-
tion between southern Africa and South America, whether via continental drift or
land bridges.
None of the opinions expressed at the symposium was surprising, but what
Holmes had to say about his own position was. “I should confess that, despite ap-
pearances to the contrary, I have never succeeded in freeing myself from a nagging
prejudice against continental drift; in my geological bones, so to speak, I feel the