The long history of mankind is studded with convergences, perhaps most notably in social systems and the use of artefacts and technology. But for human history, set in the arrow of time, there appears to be one intolerable stumbling-block. This is the catastrophic failure in human values and decency.

The Burgess Shale is not unique, but for those who study evolution and fossils it has become something of an icon. It provides a reference point and a benchmark, a point of common discussion and an issue of universal scientific interest.

The long history of mankind is studded with convergences, perhaps most notably in social systems and the use of artefacts and technology. But for human history, set in the arrow of time, there appears to be one intolerable stumbling-block. This is the catastrophic failure in human values and decency.

The way Conway Morris goes about biting the hand that once fed him would make a shoal of piranha seem decorous.

It seldom seems to strike the ultra-Darwinists that theology might have its own richness and subtleties, and might strange thought actually tell us things about the world that are not only to our real advantage, but will never be revealed by science.

The underlying reason for convergence seems to be that all organisms are under constant scrutiny of natural selection and are also subject to the constraints of the physical and chemical factors that severely limit the action of all inhabitants of the biosphere. Put simply, convergence shows that in a real world not all things are possible.

On a perfect planet such as might be acceptable to a physicist, one might predict that from its origin the diversity of life would grow exponentially until the carrying capacity, however defined, was reached. The fossil record on Earth, however, tells a very different story.