POPULATION SIZE AND GENETIC LOAD IN IRRADIATED POPULATIONS OF DROSOPHILA MELANOGASTER

Journal Article · Sun Mar 01 04:00:00 EST 1964 · Genetics (U.S.)

OSTI ID:4094676

Carson, H L

Two experimental populations of the sepia-spinelessrough stock of Drosophila melanogaster each received 65,000 r of x rays over a period of 21/2 years. Two control populations were handled in an identical manner but received no radiation. All four populations were discarded one year after the cessation of irradiation of the experimentals. The method of handling permitted weekly measurements of population size of all populations, affording a measure of fitness of the populations. As expected, the size of the experimental populations declines under radiation. Population size is recovered rapidly when radiation is suspended. Although one of the experimental populations maintained an elevated fitness level at several times for a number of generations, these effects were reversed and at the end of the experiment, controls and experimentals did not differ from one another. Following the cessation of the irradiation, the genetic loads of the irradiated populations were found to be elevated relative to the controls. These increased loads, however, disappeared within a year. Newly induced mutations do not appear to provide an important source of genetic diversity whereby fitness can be improved in experimental population systems where natural selection is operating. (auth)

• Research Organization: Washington Univ., St. Louis
• NSA Number: NSA-18-013493
• OSTI ID: 4094676
• Journal Information: Genetics (U.S.), Journal Name: Genetics (U.S.) Vol. Vol: 49; ISSN GENTA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
CHROMOSOMES
DROSOPHILA
GENETICS
INSECTS
IRRADIATION
MUTATIONS
RADIATION DOSES
RADIATION EFFECTS
REPRODUCTION
X RADIATION