Sir

In his Concepts essay “Progressive evolution: aspirational thinking” (Nature 420, 611; 2002), Henry Gee failed to mention the most obvious source (perhaps the second most obvious, after our own vanity) of the idea that evolution is progressive. This is that evolution has actually been progressive, insofar as it has produced increasingly complex organisms over time.

It may be that this has occurred by way of undirected processes, but one can hardly blame people, including scientists, for arriving at the conclusion that evolution is progressive, given its history here on Earth. Of course, this requires a value judgement that more complexity is better, but it is not surprising that human beings will think that the complexity of a human is 'better' in some sense than that of a cockroach.