Biology now dominates scientific enquiry, and headlines as well. It seems that every week geneticists claim they have accounted for yet another human trait of ailment. But out of the complex research have come exaggerations and misunderstanding of what biology. Especially genetics, can actually tell us. If we map our genes, will we be able to predict the development if our bodies, of diseases - of our personalities? Will we understand social relations better? Will we be able to create life itself? In these essays from the New York Review of Books, several of which are here updated with new epilogues, Richard Lewontin demystifies some of the most controversial issues in the life sciences today. On topics ranging from Darwin to Dolly the sheep, including biological determinism, heredity and natural selection, evolutionary psychology ad altruism, sex surveys, cloning and the Human Genome Project, he offers both sharp criticisms of the 'overweening pride' of scientists, especially those who have mistaken their social prejudices for scientific facts, and lucid expositions of the exact state of scientific knowledge. In each case, he casts an ever-vigilant and deflationary eye on the temptation to overstate the power of biology to explain everything we want to know about ourselves.