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 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 MorrisWhen discussing organic evolution the only point of agreement seems to be: ‘It happened.’ Thereafter, there is little consensus, which at first sight must seem rather odd.
Simon Conway Morris