Twins: genes, environment and the mystery of identity by Lawrence Wright Weidenfeld & Nicolson, pounds 14.99 Lifelines: biology, freedom and dete rminism by Steven Rose Allen Lane, pounds 20; Has the all-in-our-genes brigade finally won the great nature versus nurture debate? Not completely, argues Marek Kohn

Sir: This year represents, for scientists, an important double bicentenary - of the death of James Hutton and of the birth of Charles Lyell. These two men, both of them Scots, were the principal founders of the science of geology. At the time of their work, the formation of rocks was considered by some to be a product of great floods or other major terrestrial catastrophes, a consequence of the direct will of God. It was these two who turned wild speculation into good science.

Britain's role in the move to purify Europe's races

Sir: ME is not an illness of the mid-Eighties. It simply became more recognised at that time. In the 19th century people such as Charles Darwin and Florence Nightingale had its symptoms.

Scientists believe they have proved Charles Darwin was right by setting lizards on different evolutionary paths and watching the results. Darwin argued in The Origin of the Species that when organisms colonise a new territory they adapt to its conditions and eventually evolve into a new species.

Marek Kohn snarls at scientists who pretend that chimps can chat

It is the great intellectual event of the late 20th century: new discoveries in neuroscience are challenging our established ideas about morality, free will and human nature. But can science really tell the whole story?

The disaster movie was always the quintessential Seventies genre. Films such as The Poseidon Adventure, The Towering Inferno and Avalanche summed up a seedy, disillusioned decade. They were pessimism writ large... and trashy. Movies which gave new meaning to emergency flares, as a hand-picked selection of personality disordered fashion victims fell prey to whatever natural disaster had been visited on their hotel, airplane or tower block.

ESAU by Philip Kerr Chatto pounds 15.99

Sir: Ted Wragg's article (15 August) made such a sensible case against a superleague of elite universities, one can only wonder why anyone would think it a good idea.

Sir: I am delighted to see a digestible and coherent explanation of evolution aimed toward the uninitiated, but David Bodanis (The DIY University; "Evolution", 7 August) has risked misleading his readership on one or two important points.

Colin Tudge calls for the "testing of testable hypotheses" in studying behaviour ("Outrage at violence is the easy way", 14 July). But, counter to his social Darwinism, no genes have yet been found that code for anything as complex as altruism and violence. Besides, all that genes give us are capacities. Whether and how these are developed depends on the environment we interact with and create.

Marriage is a snare, a delusion, a refuge, a circus. It spells the end of romance and the beginning of... what, exactly? Is it just `a nice, soft wife on a sofa with a good fire', as Charles Darwin described it, or the greatest challenge of our lives? Roy Porter examines the secret history of an imperishable institution, and, overleaf, we hear from its advocates.

Abraham Lincoln's image