Spanish geneticists say they have discovered how bilaterally symmetric flowers evolve from radially symmetric ones.
Geneticists Francisco Perfectti and Juan Pedro Camacho, along with ecologist José Gómez -- all from the University of Granada -- explored how different flower shapes affect plant fitness in natural populations of Erysimum mediohispanicum, a Mediterranean herb.
The researchers found plants bearing bilaterally symmetrical flowers were more visited by pollinators and had higher fitness, measured by both the number of seeds produced per plant and the number of seeds surviving to the juvenile stage, than among plants with radially symmetric flowers.
"This study reveals that natural selection can play a key role in the evolution of flower bilateral symmetry," said Camacho. "Our data also suggest that it is possible to understand the evolution of complex forms by means of microevolutionary analyses, as complementary tools to those coming from developmental genetics."
The findings appear in the October issue of The American Naturalist.
Copyright 2006 by United Press International
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