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.
Simon Conway MorrisI dont think an alien will be a blob. If aliens are out there they should have evolved just like us. They should have eyes and be walking on two legs. In short if there is any life out there then it is likely to be very similar to us.
Simon Conway MorrisThe 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.
Simon Conway MorrisIf one compares the sequence of amino acids that go to form the protein haemoglobin, it becomes apparent that humans and chimps are identical and do not differ in a single site.
Simon Conway MorrisLife's Solution builds a forceful case for the predictability of evolutionary outcomes, not in terms of genetic details but rather their broad phenotypic manifestations. The case rests on a remarkable compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions.
Simon Conway Morris