Genetics of Natural Populations XLII Three Decades of Genetic Change in Drosophila pseudoobscura
Anderson WW, Dobzhansky T, Pavlovsky O, Powell JR, Yardley D. 1975. Genetics of Natural Populations XLII Three Decades of Genetic Change in Drosophila pseudoobscura. Evolution. 29(1):24-36
This part of the longterm genetic study of Drosophila compares data from 1970-1973 with earlier data from the same locations in Death Valley and other areas to help determine reasons for the observed regional patterns of genetic change. One possible cause is insecticides, and although laboratory studies did not show effects on adult flies, further studies are examining potential effects of exposing larvae. Another possible influence is "formation and spread of new adaptive gene complexes," but even after 30 years' work on the topic, reasons for the observed changes are not clear. Between 1970 and 1973 we sampled 22 populations of D. pseudoobscura which were studied at least twice, and usually three times, in the past. The frequencies of third chromosome gene arrangements were determined and compared with the accumulated data of three decades. The most striking trends over the last decade were a reduction in frequency of the PP chromosome on the Pacific coast and a concomitant increase in the frequency of TL. The long-term frequency changes of the inversion polymorphs are discussed in terms of two explanatory hypotheses: that alterations in the environment have elicited the genetic changes; and that new, more adaptive gene complexes have arisen and spread.
- Type
- Journal Article
- Authors
- Anderson, Wyatt; Dobzhansky, Theodosius; Pavlovsky, Olga; Powell, Jeffrey; Yardley, Darrell
- Units
- CHIS , DEVA
- Keywords
- Absence (Biodiversity), Animal Studies, CA, CA, Channel Islands National Park, Death Valley National Park, Distribution (Biodiversity), Drosophila pseudoobscura (Diptera: Drosophilidae), Genetic Studies, insect survey, NV, Panamint Mountains, Presence (Biodiversity), Santa Cruz Island, Taxa Links To Datasets, Taxa Links To References, Terrestrial Invertebrates