The uneasy marriage of biology and engineering raises big questions about the nature of life.

In a world where biology and engineering intersect, how do you decide what's "natural"?

Biotechnology is making it easier and easier to create new forms of life, but what are the consequences when humans play with life? We travel back to the first billion years of life on Earth, take a look at how modern engineers tinker with living things, and meet a woman who could have been two people.

***Mix and Match

***Genes on the Move

***Intelligent Design?

[April 6, 2008]