Drosophila melanogaster is a model organism for the study of genetics and some laboratory populations have been bred for different life-history traits over the course of 30 years. Professor Michael Rose, of UC Irvine, began breeding flies with accelerated development in 1991 (600 generations ago). Doctoral student Molly Burke compared the experimental flies with a control group on a genome-wide basis. This is significant because it is the first time such a study of a sexually reproducing species has been done. Burke examined specific genes and also obtained “whole-genome resequencing data from Drosophila populations that have undergone 600 generations of laboratory selection for accelerated development.” The results are noteworthy on several counts:
“For decades, most researchers have assumed that sexual species evolve the same way single-cell bacteria do: A genetic mutation sweeps through a population and quickly becomes “fixated” on a particular portion of DNA. But the UCI work shows that when sex is involved, it’s far more complicated. “This research really upends the dominant paradigm about how species evolve,” said ecology and evolutionary biology professor Anthony Long, the primary investigator.”
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