Hanging on for Lizzy to get her man | Brief letters

Homo sapiens | Pride and Prejudice | Formula for happiness | Messrs Block and Anderson | The Yotam effectHomo sapiens is the world’s most productive trader, whatever that means, in an ecosystem teeming with life, writes Christine McNulty (Letters, 17 April). Then why is it that the number of wild animals in the world has declined by over 50% since 1970, and that the rate of extinction of species is now somewhere between 1,000 and 10,000 times the natural background rate? It seems to me tha