Wednesday, August 15, 2007

Old Flowers: New Evidence

Imagine what the earth was like 80 million years ago: the sights, the smells, the sounds.... I bet your mind didn't leap straight to orchids, did it? But scientists at the Harvard Museum of Comparative Zoology are buzzing about new evidence that the first orchids are old enough to have lived that far in the past, right alongside dinosaurs.

To what do we owe this newfound vision of T-rexes tromping along next to showy flowers? Why, to a bee! Lucky for us (though not for the bee), sometime around 15 or 20 million years ago a bee was covered in tree resin as it went about its daily business. Over millions of years, as the tree was buried, the sap hardened into amber with the bee trapped inside. Eventually, someone found the preserved fossil in the Dominican Republic and brought it to the Harvard Museum to study.

So how did a 15 million year old bee tell us about 80 million year old orchids? As it turns out, the amber preserved not only the ancient bee, but also the pollen grains it was carrying on its back. By carefully studying the pollen grains, the scientists were able to determine not only what kind of plant they were from but also how they relate to modern species.

This find was particularly exciting to scientists, because it's the first window into orchid evolution they've discovered. "It's absolutely fantastic," an orchid specialist told Nature magazine. "It's what the orchid community has been waiting for, for a long time."