Abstract
The ‘Afterword’ provides a brief summary and concludes that our modern view of evolution is remarkably close to that of Wallace and Darwin. The chief difference is that two advances mean that the process of evolution through selection acting on random mutations of the genetic material is now much more credible than it was at the beginning of the 20th century. Firstly, we have a much richer body of data demonstrating the action of natural selection at every level of biological organization, from protein molecules to complex behaviour patterns. Secondly, we also now understand the mechanism of inheritance.