... The theory of speciation via the founder principle. Genetics,94, 1011-1038. Population crash, population flush and genetic variability in cage populations of Drosophila melanogasterF.A. ... experiments. In January 1979 three times 60 pairs of flies of theOregon strain were placed in population cages at 21°, 25° and 29 °C, respectively.The 21 and 25 °C populations ... further that genetic variability. We were able, a few months after their foundation, to estimate and comparethe genetic variability of various cage populations, maintained for...