SURVEY OF SOCIAL INSECTS 
IN THE FOSSIL RECORD* 
By Laurie Burnham 
Museum of Comparative Zoology, 
Harvard University, 
Cambridge, Massachusetts 02138, U.S.A. 
Biologists have long been intrigued by the complex social systems 
of various insects. Despite a voluminous literature dealing with the 
evolution of these systems, immense gaps remain in our understand- 
ing of insect sociality. Several theories have been proposed to 
explain the evolution of social behavior in certain groups of insects 
(e.g., Hamilton, 1964), but none consider this problem with respect 
to geological time. The present paper does so by examining the 
fossil record for clues not only on the antiquity of sociality, but also 
on the nature of these early social insects. Included in this survey are 
those insects recognized as eusocial: the Isoptera, and three super- 
families of the Hymenoptera: Vespoidea, Formicoidea, and 
Apoidea. 
ISOPTERA 
The termites are remarkable in two regards: 1) as a group, they 
are fully eusocial, exhibiting a wide range of behavioral modifica- 
tions and sophistications, and 2) their record in the geological past, 
although sparse, is highly indicative of an Early Mesozoic origin. 
This latter point is of particular significance if one considers 
sociality among insects as a pinnacle of evolutionary success. 
Wilson (1971, p. 1) states that “[insect societies] best exemplify the 
full sweep of ascending levels of organization, from molecule to 
society.” The possibility that termites evolved a social organization 
as far back in geological time as the Jurassic (roughly 190 million 
years ago) is of great interest, particularly when attempting to draw 
parallels with the evolution of sociality in the Hymenoptera, a group 
phylogenetically very remote from the termites. 
* Manuscript received by the editor July 7, 1978. 
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