for National Geographic News
New cures, supercrops, and secrets of evolution may emerge from the fast-growing branches of the "Tree of Life," scientists say.
The increasing availability of genetic informationand the computer technology to analyze itis allowing researchers to begin drawing a detailed picture of how life on Earth originated, adapted, and diversified.
"A huge amount of progress has been made over the last decade," said Michael Donoghue, a biologist at Yale University in New Haven, Connecticut.
Donoghue attributes the progress to revolutions in molecular biology and computer technology that allow scientists to see at the genetic level how species are related to each other.
When plotted on a page the information looks like a giant, bushy tree, hence the project's nickname.
Donoghue is part of an army of scientists working in teams around the U.S. to assemble the tree.
According to Donoghue, scientists extract information from the Tree of Life by making comparisons among species' genomes.
A genome is an life-form's complete set of DNA. The human genome, for example, contains some 3 billion base pairs, which code for the approximately 30,000 genes that define a person's unique traits. (See a quick overview of human genetics.)
Tree of Life scientists can determine the uniqueness of a particular gene in the human genome by comparing the human genome to genomes of other species.
For instance, they might ask if a particular human gene is shared with chimpanzees, our closest animal relatives. If not, the gene is probably unique to humans. (Related: "Chimps Belong on Human Branch of Family Tree, Study Says" [May 2003].)
If the gene is shared with chimpanzees, is it also shared with some of humanity's more distant relatives, say mice or frogs? What about yeast?
SOURCES AND RELATED WEB SITES