Evolution (Evolution)

by whitecraw, Tuesday, April 01, 2008, 00:03 (6079 days ago) @ David Turell

'Since beneficial mutations are in a minority, individuals in a species may survive, but survival of the species may be in doubt because the quality of the individuals presented for 'selection' may actually decline over time. Natural Selection is a competition it is true, but unless top-notch competitors appear, the species may disappear. And there is no guarantee from random mutation, that top-notch organisms will be there to compete. No capitalist corporation would chose its upper officers by a method that has its board pick from candidates that had never been evaluated prior to their presentation. That would be asking for chaos. What is amazing is that evolution has proceeded from simple to complex despite the passivity of the process. Remember 99% of species are extinct.' - This is all true. But it assumes: a) that the competition for survival, which determines which individuals within a population survive to pass on their characteristics to subsequent generations, is a 'top-notch' competition; and b) that natural selection is a progressive or directional process, proceeding from simple to complex. Both of these assumptions are false. - a) The survival of a species is always in doubt, since the 'quality' of the individuals that make up its populations is always relative to the conditions of life that obtain at any time. 'Top-notch' competitors in one environment can quickly become lame ducks when that environment changes, and vice versa. Darker coloured variants within a species of moth might be advantaged in the competition for survival over lighter coloured variants in a sooty environment, since they are less conspicuous to predators; but take away the dark satanic mills and the lighter coloured variants will suddenly gain the upper hand. In other words, there are no such things as 'beneficial' and 'deleterious' variations in any sort of absolute sense; there are only qualitatively neutral variations which either 'fit' variant individuals to the fickle conditions of life that obtain or not, and which sometimes do and sometimes don't. - b) The random mutations that occur all the time in DNA sequences and give rise the tremendous fecundity of variation within species do not indeed guarantee progressive evolution and, in particular, evolution in the direction of greater complexity. But evolution is not a progressive process. It does not proceed in any particular direction or towards any particular end, let alone in the direction/towards the end of greater complexity. Species do indeed disappear as a result of environmental changes for which they are not 'fitted' in any of the individual variations they encompass in their classification; but species of complex organisms are just as susceptible to extinction as species of simple organisms. Indeed, in this respect, it is species of simpler organisms that are more resilient and thus must be judged more successful in evolutionary terms, for no other reason than that they have been around the longest. In purely evolutionary terms, it's survival that is the gold standard, and not complexity or intelligence or consciousness; and in evolutionary history, it is the simplest organisms that have proven themselves to be the greatest survivors, which gives them the greatest claim to being top of the evolutionary league. I bet that long, long after we become extinct following our brief efflorescence as a special life-form, there will still be thread-like tubes having sex in the darkness of the ocean floor, just as there were long, long before even the first sponge ... now that's an evolutionary success story.