Mating Preferences and Sexual Isolation Within and Between the Incipient Species of Drosophila Paulistorum

Abstract

The "male choice" experimental method was used to test mating preferences of six races of Drosophila paulistorum. The races (number of strains in parentheses) are: Centro-American (3); Amazonian (4); Orinocan (5); Andean-South Brazilian (6); Transitional (4); and Guianan (1).

TRANSITIONAL POPULATIONS OFDROSOPHILA PAULISTORUM

“…Hybrid sterility, restricted to the male sex, probably plays a secondary, if any, role in nature. The early work on ethological isolation (Carmody, et al, 1962) used the so-called "male-choice" technique; females of two strains were confined with males of one of them and, after a certain time had elapsed, all the females were dissected and their seminal receptacles were examined under a microscope for the presence of sperm. More recently (Ehrman, 1965), a technique of direct observation of flies in so-called observation chambers became the standard one.…”

Untitled

“…Table 2 is a summary of the data resulting from the tests of the Llanos strain with strains of the Orinocan and other semispecies. Most of these tests have been published in Carmody et al (1962), where the figures for separate crosses can be found. It is possible that many of these tests were made before Llanos-A changed to K ew Llanos.…”

“…The career of the Llanos strains has been reported in several publications, partly or wholly concerned with that strain (Dobzhansky and Spassky 1959, Dobzhansky and Pavlovsky 1966, 1967, 1971, Carmody et al, 1962, Perez-Salas et al, 1970. The present article is intended to be the last and concluding report.…”

DROSOPHILA IMAII,A NEW SIBLING SPECIES RELATED TODROSOPHILA BIFASCIATA

“…Carmody et al (1962) have found that "the two isolating mechanisms, sexual isolation and hybrid sterility are quite different in genetic basis." In the present case, the hybrid males between D.…”