A switch to pass-fail grading is curbing the "perfection" culture among U.S. nuclear missile forces. Critics of the old way say striving to be perfect invited cheating by those who launch the nukes.
The string of genes that make a man a man used to be much bigger, and some geneticists say it may be wasting away. Back off, others say. Y has been stable — and crucial — for millennia.
Birds are everywhere, but the greatest concentration of different birds — the "bird mecca" of America — is not in our great parks, not in our forests, not where you'd suppose. Not at all.