New study finds gene sharing only modestly contributed to the plant family’s remarkable diversity

Containing more than 850 species, fig trees are one of the most diverse groups of plants in the world.

To unravel how this plant genus (Ficus in the Moraceae family) evolved to become such a diverse group, an international team of researchers, including a Northwestern University plant biologist, examined 1,858 genes from 520 species of figs.

Although previous researchers have hypothesized that fig diversity arose from widespread gene sharing across fig species, the new study instead suggests that gene sharing only modestly contributed to figs’ evolution. The new analysis paints a picture of stable evolution within lineages, punctuated by only occasional instances of cross-species gene sharing.

The study was published earlier this month in the Proceedings of the National Academy of Sciences.

“When most people think of figs, a sweet, chewy treat comes to mind. But that tasty treat represents just one species,” said Nyree Zerega, a Northwestern botanist who co-authored the study. “Figs are one of the most diverse groups of plants and ecological keystones in a variety of habitats around the world. Their evolutionary history and how they become so diverse has been difficult to unravel.”

Nyree Zerega

Zerega is the director of the Program in Plant Biology and Conservation, a partnership between Northwestern and the Chicago Botanic Garden. The study was led by Elliot M. Gardner, who received his Ph.D. at Northwestern and is now an assistant professor at Case Western University.

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