The Evolution of the Dacetine Ants

Abstract

A preliminary synthesis of evolutionary studies of certain morphological and ethological characters in the ant tribe Dacetini is given. A primary trend inferred from the study of living species is the shift from epigaeic-subarboreal to cryptic-terrestrial foraging. Possibly associated in the early stages of dacetine evolution with this shift was a trend toward oligophagous predation, resulting in extreme cases among modern forms in specialized feeding on collembolans. Secondary changes have occurred in hunting behavior and in a diversity of morphological features; these are described briefly. Reversed or, more accurately, countercurrent evolution has occurred in various phyletic lines in most of the characters of this morphological-ethological coadaptive system. Such changes are relatively short-range and usually involve only a few characters at a time. In at least some instances they have produced a local reversal in the overall dacetine trend to specialization, as with secondarily increased polyphagy ...