It is now well known that the concept of drifting continents became an
estab- lished theory during the 1960s. Not long after this "revolution
in the earth sciences," researchers began applying the continental drift
model to problems in historical biogeography. One such problem was the
origin and dispersal of the New World monkeys, the Platyrrhini. Our
interests in this subject began in the late 1960s on different conti-
nents quite independent of one another in the cities of Florence, Italy,
and Berkeley, California. In Florence in 1968, A. B. Chiarelli, through
stimulating discussions with R. von Koenigswald and B. de Boer, became
intrigued with the possibility that a repositioning of the continents of
Africa and South America in the early Cenozoic might alter previous
traditional conceptions of a North American origin of the Platyrrhini.
During the early 1970s this con- cept was expanded and pursued by him
through discussions with students while serving as visiting professor at
the University of Toronto. By this time, publication of the Journal of
Human Evolution was well underway, and Dr. Chiarelli as editor
encouraged a dialogue emphasizing continental drift models of primate
origins which culminated in a series of articles published in that
journal during 1974-75. In early 1970, while attending the University of
California at Berkeley, R. L. Ciochon was introduced to the concept of
continental drift and plate tectonics and their concomitant applications
to vertebrate evolution through talks with paleontologist W. A. Clemens
and anthropologist S. L. Washburn.