Scientists are still fleshing out Darwin's theory of evolution | Letters

There can be no one unifying theory, writes Prof Jonathan Bard, while Nicholas Maxwell looks to the role of purposive actions and Pete Bibby says the fittest theory will survive Stephen Buranyi misses some key points in his article (Do we need a new theory of evolution?, 28 June). Darwin saw novel speciation as resulting from natural selection acting on anatomical variants, but that simple skeleton needed fleshing out. It took a century of research, for example, for us to understand the importan...