Budding Ideas: Recent Arboretum research

November 18, 2011
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Living, But Not Fossils

Palm-tree-like plants called cycads are often depicted as living fossils surviving from the age of the dinosaurs. But scientists have debunked that idea, proving that modern cycads are different plants that evolved much more recently.

The plants with spiky trunks and long evergreen fronds indeed existed in the Jurassic period, which ended about 145 million years ago. But the living versions are totally different species that evolved within the past 10 million years, long after the age of dinosaurs. The species began to diversify around the globe at the same time, suggesting that a cooling climate may have been a trigger.

The discovery came from fossil and DNA research by Dr. Nathalie Nagalingum of Sydney, Australia’s Royal Botanic Gardens. The fundamental research came from Arnold Arboretum’s Tree of Life project, which traces the evolution of all non-flowering seed plants. It is headed by Arboretum researcher Dr. Sarah Mathews, a co-author on the study. The discovery was published last month in the journal “Science.”

From press materials.

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