Twenty thousand years ago, humans lived in grassy tundras near the Arctic Circle. Trees were scare in these cold, dry regions, so Ice Age hunters could not build campfires using wood. Instead, these hardy humans made campfires by burning the bones of the big animals they hunted. Few modern people know how to make a bone fire. Recently, a Colorado archeologist and some volunteers gave it a try. From Longmont, Colorado, Shelley Schlender reports.
