Apr. 1, 2010 A hitherto unknown reproductive system in a species
closely related to the olive tree, Phillyrea angustifolia L.,
has been discovered by researchers in France. This system
explains the high concentration of male individuals co-occurring
with hermaphrodites in this species. The hermaphrodites, whose
blossoms bear both male and female organs, are divided into two
morphologically indistinguishable groups. The plants of each
group are sterile among themselves but fully compatible with
those of the other group. Under these conditions, the
hermaphrodites can fertilize only half of the pollen recipients,
whereas the males can pollinate all the hermaphrodites. The
disadvantage weighing upon the males is thus neatly
counterbalanced. This discovery proves for the first time the
possibility of an evolutionary transition from hermaphroditism
to dioecy. A report has been published in Science. Researchers
at the Laboratoire de Génétique et Évolution des Populations
Végétales (CNRS/Université de Lille 1) and th