How is Race defined? Why does it Matter?

Listen to this great piece from Radiolab about the various ways that Race is defined and what it means.

Find the show here: Race

Excerpt from the show:

The U.S. Census defines five races, and an "other" category. When the human genome was first fully mapped in 2000, Bill Clinton, Craig Venter, and Francis Collins took the stage and pronounced that "The concept of race has no genetic or scientific basis."

Great words spoken with great intentions. But what does that mean and where does it leave us? It doesn't seem to have wiped out our evolving conversation about race.