Guest: Bryan Sykes.

What if we could trace our genetic makeup all the way back to fewer than ten primeval individuals? In fact, says geneticist Bryan Sykes, we can. He joins us today on Focus to explain how the study of a 5,000-year-old man's frozen remains in Italy led to the discovery of a particular strand of DNA that can be traced back to seven prehistoric women: The Seven Daughters of Eve.

Guest: Stephen Palumbi.

Evolution is generally thought of as a slow process, one that takes millions of years. In fact, evolution can occur very quickly, and our own has been dramatically influenced by our efforts to improve our quality of life. Today on Focus we'll talk with biologist Stephen Palumbi about his book The Evolution Explosion. He says that humans have accelerated the evolutionary game, especially with the species closest to us: the food we eat, the pests that share the food, and the diseases that plague us. All of this raising the question: can we survive our own power to reshape the Earth?

Guest: Steven Jay Gould.

The Burgess Shale is a small limestone quarry in the Canadian Rockies. Seemingly unobtrusive, it in fact holds the remains of a 530-million-year-old sea and all the creatures that dwelled within it. Paleontologist Stephen Jay Gould joins Focus today to talk about the Burgess Shale and what it can tell us about evolution and natural history.