The Origin of the Mighty Oak

This week's Science Monday comes from the journal of the same name.
The mighty oak.  One of my favorite trees.
It is pretty universally popular, it turns out.  The oak is the national tree of the United States, Germany, and a dozen other countries—as well as the stuff of fine wine barrels—yet little is known about where the North American oak tree came from. Now, biologists have pieced together the past of the most dominant species of oaks and come to a startling conclusion: The mother of all oaks didn’t arise in the tropics, as many botanists thought, but rather near the Arctic Circle, then spread southward.
It is perhaps a spectacular example of an ecological opportunity in the south that allowed for an explosive species diversification.  To reconstruct the mighty American oak’s history, Andrew Hipp, a plant systematist at the Morton Arboretum in Lisle, Illinois, and colleagues obtained tens of thousands of pieces of DNA from 300 trees representing 146 oak species. That enormous amount of genetic material allowed the team to conduct comparisons that revealed which species are most closely related, and avoid the confusion created by genes that jump between the branches of a family tree when two species interbreed. “This is a demonstration of the power of next-generation sequencing techniques to unlock some previously intractable problems,” Pennington says. Hipp’s team also used oak fossils to help it date when certain branches of this family tree arose.