Genescient’s Methuselah flies are more vigorous. “They beat up the other flies and take their women away,” said Gregory Benford, a retired UC Irvine physics professor.
Interpretation of genetic data from fruit flies bred for longevity suggests the major culprit may not be accumulated damage…
Through selective breeding, Dr. Rose was able to create a long-lived line of creatures he called Methuselah flies. He then put his research into reverse and developed flies with much shortened life spans.
This Discover magazine article from 1992, discusses Methuselah genes.