What will you have done to your newborn when you have installed into the nucleus of every one of her billions of cells a purchased code that will pump out proteins designed to change her? You will have robbed her of the last possible chance for creating context--meaning--for her life. Say she finds herself, at the age of sixteen, unaccountably happy. Is it her being happy--finding, perhaps, the boy she will first love--or is it the corporate product inserted within her when she was a small nest of cells, an artificial chromosome now causing her body to produce more serotonin? Don't think she won't wonder: at sixteen a sensitive soul questions everything. But perhaps you've "increased her intelligence"--and perhaps that's why she is questioning so hard. She won't be sure if even the questions are hers. Bill McKibben writes regularly for The New York Review of Books, The New York Times, Natural History, The New Republic, and many other publications. His first book, The End of Nature, was published in 1989 after being excerpted in The New Yorker and was a national bestseller. His other books include The Age of Missing Information, Maybe One, and Long Distance: A Year of Living Strenuously. He lives with his wife, the writer Sue Halpern, and daughter in Vermont.