Cosmologists make precise predictions about what will happen to the universe in 20 billion years time. Biologists struggle to predict how a few bacteria in a dish might evolve over 20 hours. Some claim that this lack of precise predictive power means evolution is not scientific.
However, what matters in science is not how much you can predict on the basis of a theory or how precise those predictions are, but whether you can make predictions that turn out to be right. Meteorologists don't reject chaos theory because it tells them it is impossible to predict the weather 100 per cent accurately - on the contrary, they accept it because weather follows the broad patterns predicted by chaos theory.
The difficulty in predicting the path of evolution partly springs from organisms' freedom to ...
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