The long-running series in which readers answer other readers’ questions on subjects ranging from trivial flights of fancy to profound scientific and philosophical concepts
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hy aren’t more animals hermaphrodites? Snails and worms seem to have been successful using that method for sharing genes between any two individuals, but vertebrates evolved away from it. Why? Janet Lesley, Kent, UK
Send new questions to nq@theguardian.com.
Because it takes all the fun out of courtship. Richard Orlando






