Rapid Evolution of a Geographic Cline in Size in an Introduced Fly

• Published in: Science (American Association for the Advancement of Science) Vol. 287; no. 5451; pp. 308 - 309
• Main Authors: Huey, Raymond B., Gilchrist, George W., Carlson, Margen L., Berrigan, David, Serra, Luís
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 14.01.2000; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Animals; Biological and medical sciences; Biological Evolution; Clines; Communicable Diseases; Convergent evolution; Drosophila - anatomy & histology; Drosophila - genetics; Drosophila subobscura; Europe; Evolution; Evolutionary genetics; Female; Females; Fundamental and applied biological sciences. Psychology; Genetic inheritance; Genetics of eukaryotes. Biological and molecular evolution; Geography; Habitats; Insects; Male; Males; Microsatellites; Natural selection; North America; Population growth; Predictability; Research fellowships; Sex Characteristics; Time Factors; Wings, Animal - anatomy & histology; North America; America; Europe; Biometrics; Wing; Introduced species; Latitudinal variation; Insecta; Biological evolution; Drosophilidae; Arthropoda; Morphology; Invertebrata; Drosophila subobscura; Diptera; Geographical variation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.287.5451.308

The introduction and rapid spread of Drosophila subobscura in the New World two decades ago provide an opportunity to determine the predictability and rate of evolution of a geographic cline. In ancestral Old World populations, wing length increases clinally with latitude. In North American populations, no wing length cline was detected one decade after the introduction. After two decades, however, a cline has evolved and largely converged on the ancestral cline. The rate of morphological evolution on a continental scale is very fast, relative even to rates measured within local populations. Nevertheless, different wing sections dominate the New versus Old World clines. Thus, the evolution of geographic variation in wing length has been predictable, but the means by which the cline is achieved is contingent.