Abstract
Adaptation may be a key element in biological evolution, but it is only one component. We'll talk about everything else. On the one hand, there is drift, the random counterpart of natural selection, which should never be underestimated. Then there's the " tinkering of evolution ", the source of biological systems that are only optimal in certain respects. And last but not least, there is the multiplicity of scales of individuality, giving rise to genetic conflicts : what is adaptive for my transposable elements or my mitochondria is not necessarily adaptive for me...
