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've been talking about the Stone Age but now we're living in what some scientists are calling the anthropocene. Maybe you've never heard of that word. It's a time where everything on the planet is touched by humans in some way, whether it's directly, like clear cutting forests or suppressing fires, or indirectly by the effects of climate change. Is this, as the environmentalist Bill McKibben wrote, oh, 20 years ago, is this the end of nature?
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.
"The more humble we are in the face of our experience with the natural world ... the more we're going to find a healthy coexistence with it." — Bernie Krause, bioacoustician
Every species plays a crucial role in our natural world. But when humans tinker with the equation, a chain reaction can cause entire ecosystems to break down. In this hour, TED speakers explain how everything is connected in nature, with some bold ideas about how we can restore the delicate balance and bring disappearing ecosystems back.
Bernie Krause has been recording the wild — the wind in the trees, the chirping of birds — for 45 years. He has seen many environments radically altered by humans, sometimes even by practices thought to be environmentally safe.