If the greatest living American were a tree, it would probably be the chestnut. Nat King Cole sang about it. Abraham Lincoln probably built his log cabin from it. The telegraph era, which required tall poles of strong wood, was enabled by it.

In the first half of the 20th century, however, the American chestnut fell victim to a fungus unintentionally imported from China, and the tree that once dominated the forest canopy of the eastern U.S. all but disappeared. Now it is on the cusp of a comeback, a testament to America's scientific ingenuity.

For years, scientists tried without success to develop a strain of chestnut tree that was immune, using traditional hybridization methods to instill resistance from Chinese chestnut trees into the American variety. Now plant scientists have found a way to develop a chestnut tree that fights off the fungus. Borrowing a gene from wheat, they created a strain that produces a substance that neutralizes the fungus's lethal acid. What's more, this trait is passed along to seedlings. Versions with even greater resistance are in development.

In the last few years, researchers have planted several experimental stands of the trees. If they get approval from the Environmental Protection Agency and Department of Agriculture, these genetically modified chestnut trees will be planted in the wild.

This experiment is the first to attempt to rescue a species from extinction using genetic modification. There are also efforts afoot to find genetic solutions to diseases and pests that have killed many of North America's elm, ash and eastern hemlock trees.

David Fuller's view

Welcome news for Americans to celebrate on their 4^th of July holiday.