In the last few days it seems that every where I look there is something about evolution. And I mean it in the sense of Darwinian evolution explicitly stated and talked about, not just in the sense that I see things throughout the glasses of Darwin.

First thing is that The Guardian, a well known paper in the UK, released 10 days ago in the Saturday edition what they call The definitive guide to the book that changed the world. The book is On the origin of Species by Darwin and the introduction comes from Richard Dawkins. The booklet contains extracts from the book and the interpretation of the book idea’s nowadays. A worthy and easy read and came free with my favourite British newspaper.

Second, a friend in Nashville (hi Simon!) sent me a couple of days ago a review in Science (and also a comment in another blog) about Behe’s rather infamous book “The Edge of evolution”. I am quite keen on reading books coming from people that argue against and in favour of evolution but the reviews (and comments from people I know that had read it) are quite discouraging and although the book claims to contain a mathematical proof of the unlikelihood of evolution to produce the diversity and complexity of what biology studies, a mathematical proof is only as good as the assumptions on which it is based. Behe, according to these reviewers, seems to make many mistakes with assumptions that render his proof useless. His point being that genetic mutations that actually contribute to an improvement of the fitness of the individual are necessarily improbable.

People accuse Behe of many things, including giving weapons to religious fundamentalists that might not be interested in science and reason but might just pick whatever supports their ideologies (I won’t use the word idea here) and advance their cause. Truth is, though, that Behe seems to at least accept that the world is older than just a few thousand years and that variation, heredity and natural selection account for some of the diversity in nature. His mathematical proof is likely to be wrong and based on wrong assumptions but so are many of the ideas presented by many scientists. Good thing about science is that, with time and accumulation of evidence, the right scientific theories eventually come out stronger whereas the weaker ones become extinct, which sounds like evolution, doesn’t it? Arguments like those of Behe or the ones about how specific biological structures could not come as a result of gradual change (see for instance the evolution of flagella), seem to stimulate many scientists to come (as they have done rather successfully so far) with convincing evolutionary trajectories that explain the emergence of these structures. This only makes the case for evolution stronger,

In the case of cancer there seems to be enough evidence that tumour cells in tumours at an advanced stage of development differ significant from the cells in the tissue and the genetic difference allows them to outcompete healthy cells. This should make it difficult to argue against the fact that genetic mutations and natural selection lead to increasing complexity and adaptation.