This is SCIENCE FRIDAY, I'm Ira Flatow. We're broadcasting from the Wisconsin Institutes for Discovery in Madison, home this week of the Wisconsin Science Festival. Astronomers and astrophysicists have traditionally, for centuries, looked upwards to the sky to learn more about the universe. We've launched telescopes into space. We have sent probes beyond our solar system to study dark matter, colliding galaxies, how the planets formed.
We're living in the epoch some scientists call the "Anthropocene"�"an age in which human influence touches nearly everything on the planet. Forty years after the signing of the Endangered Species Act, and nearly 50 years after the Wilderness Act, do we need to rethink how we protect nature? Environmental historian William Cronon and environmental geographer Paul Robbins discuss protecting wild places in the age of climate change.
For those who think the forces of natural selection no longer apply to modern humans, paleoanthropologist John Hawks would urge you to reconsider. In recent times — that's 10 to 20 thousand years, for a paleoanthropologist — Hawks says we've picked up genetic variations in skin color, and other traits that allow us to break down starch and digest cheese.