Table 1.
Life expectancies at eclosion in days for male and female medflies
| Diet | No. of cohorts | Life expectancy, males | Life expectancy, females | Difference female–male |
|---|---|---|---|---|
| Sugar plus protein | 33 | 15.2 ± 2.4 | 16.5 ± 2.5 | 1.30 ± .81 |
| Sugar only (protein-deprived) | 33 | 14.3 ± 2.1 | 12.1 ± 1.8 | −2.24 ± .28 |
| Difference sugar-plusprotein minus sugar only | 0.84 ± .56 | 4.4 ± .53 |
Reported are samples means ± SEM. Medflies are maintained on either protein-deprived or sugar-plus-protein diets. Total number of flies is 416,289. The change in the difference of female minus male life expectancies from the sugar-plus-protein diet to the protein-deprived diet demonstrates the reversal of the life expectancy sex differential (P < 10−3). Life expectancies for males do not differ significantly between sugar-plus-protein and sugar-only groups (P = 0.14), whereas for females they differ significantly (P < 10−3).