From Peter Inkpen, Amersham, Buckinghamshire, UK
Michael Marshall's fascinating article on the first 3.5 billion years of life on Earth reinforces how fleeting human history is when placed in the context of such a vast period (12 January, p 28). A fantastic way to convey this point would be to represent the history of life along a walk in a popular location. I envisage plaques at waypoints detailing significant evolutionary and geological events in our planet's 4.5-billion-year history.
For example, such a walk could start with Earth's formation at the Tower of London and run along the side of the Thames to end with the present day at the Houses of Parliament. This route is about 4.5 kilometres long, so would create a scale of 1 million years per metre walked. That would mean a critical part of human history, from the 12,000 years ago, when the shift to farming began, occupies the final 12 millimetres of the walk. And the period since the – a sobering point to reflect upon when arriving at Parliament.
