Mara Hvistendahl has written a powerful and provocative book entitled Unnatural Selection: Choosing Boys Over Girls and the Consequences of a World Full of Men. She demonstrates that in China, India and other nations, there are many more men than women, the result of systematic campaigns against baby girls. In nature, 105 boys are born for every 100 girls. Jonathan Last writes ?this ratio is biologically ironclad. Between 104 and 106 is the normal range, and that?s as far as the natural window goes. Any other number is the result of unnatural events.? However, in India today there are 112 boys for every 100 girls born. In China the number is 121, with some towns in China over 150! Why this incredibly skewed ratio? One reason?abortion.