Genetic Evidence Clears Ben Franklin
|10:58:01 PM, Sunday, August 28, 2011|
"The DNA evidence is in, and Ben Franklin didn't do it. Genetic tests on more than 1,000 Chinese tallow trees from the United States and China show the famed U.S. statesman did not import the tallow trees that are overrunning thousands of acres of U.S. coastal prairie from Florida to East Texas.
"It's widely known that Franklin introduced tallow trees to the U.S. in the late 1700s," said Rice University biologist Evan Siemann, co-author the new study in this month's American Journal of Botany. "Franklin was living in London, and he had tallow seeds shipped to associates in Georgia."
What Franklin couldn't have known at the time was that tallow trees would overachieve in the New World. Today, the trees are classified as an invasive species. Like Asian carp in the Great Lakes and kudzu vines in the eastern U.S., the trees are spreading so fast that they're destroying native habitats and causing economic damage.
Each tallow tree can produce up to a half million seeds per year. That fertility is one reason Franklin and others were interested in them; each seed is covered by a waxy, white tallow that can be processed to make soap, candles and edible oil.
Siemann, professor and chair of ecology and evolutionary biology at Rice, has spent more than 10 years compiling evidence on the differences between U.S. and Chinese tallow trees. For example, the insects that help keep tallow trees in check in Asia do not live in the U.S., and Siemann and his colleagues have found that the U.S. trees invest far less energy in producing chemicals that ward off insects. They've also found that U.S. trees grow about 30 percent faster than their Chinese kin..."