We all came from hermaphrodites, organisms with both male and female reproductive organs. And though the origin traces back more than 100 million years, biologists have scratched their heads over how and why the separate male and female sexes evolved. Now, research on wild strawberry plants is providing evidence for such a transition and the emergence of sex, at least in plants. And the results, which are detailed in the December issue of the journal Heredity, likely apply to animals like us, the researchers say. The study showed that two genes located at different spots on a chromosome can cast strawberry offspring as a single sex, a hermaphrodite or a neuter (neither male nor female, and essentially sterile). The researchers suspect the two genes could be responsible for one of the earliest stages of the transition from asexual to sexual beings. ‘All of the animals and plants that are bi-sexual, or have two sexes, are theorized to have evolved according to a particular set of steps,’ said researcher Kim Lewers, a plant geneticist at the USDA’s Genetic Improvement of Fruits and Vegetables Lab in Maryland. ‘Until now, no example had been found of the very earliest steps. […]