Showing papers by "Robert R. Sokal published in 1971"

Changes in microgeographic variation patterns of pemphigus populitransversus over a six-year span.

Abstract: Eight characters of the alate fundatrigeniae of the gall producing aphid Pemphigus populitransversus Riley were measured in samples from eight closely situated localities during the years 1961, 1964, and 1966. It was of interest to find whether the pattern of geographic variation described by Rinkel (1965) from samples collected in 1961 is retained or changed in collections from 1964 and 1966. The magnitude of such changes in a microgeographic situation must be known if changes in a wider space or time frame are to be interpreted correctly. The inferences that can be drawn from certain variation patterns about the population biology of P. populitransversus specifically, and other organisms in general, will also be discussed. The present emphasis on population studies in evolutionary research has led to an active interest in population phenetics and the inferences about population structure and evolutionary mechanisms that may be drawn from such investigations (see Sneath and Sokal, 1972, for a general review). In spite of an increasing number of recent studies in this field (Ehrlich, 1965; Soule, 1967; Johnston, 1969; Koehn et al., 1971; Selander, 1970) we still are not in a position to make general statements about classes of phenetic variation patterns to be found in nature nor about the types of population structure such patterns would reflect.