Darwin's dangerous Idea!

Darwin’s Dangerous Idea

There is one scientific idea which, to my mind, excels all others. It is exquisitely simple and beautiful. It explains the origins of all life forms and all biological design. It does away with the need for God, for a designer, for a master plan or for a purpose in life. Only in the light of this idea does anything in biology make sense. It is, of course, Darwin’s idea of evolution by natural selection.

The implications of natural selection are so profound that people have been awe-struck or maddened; fascinated or outraged, since it was first proposed in The Origin of Species in 1859. This is why Dennett (1995) calls it Darwin’s Dangerous Idea. Sadly, many people have misunderstood the idea and, even worse, have used it to defend indefensible political doctrines which have nothing to do with Darwinism. I therefore hope you will forgive me if I spend some time explaining it as clearly as I can.

All you need for natural selection to get started is a replicator in an appropriate environment. A replicator is something that copies itself, though not always perfectly. The environment must be one in which the replicator can create numerous copies of itself, not all of which can survive. That’s it.

Can it really be that simple? Yes. All that happens is this - in any one copying generation, not all the copies are identical and some are better able to survive in that environment than others are. In consequence they make more copies of themselves and so that kind of copy becomes more numerous. Of course things then begin to get complicated. The rapidly expanding population of copies starts to change the environment and that changes the selective pressures. Local variations in the environment mean different kinds of copy will do well in different places and so more complexity arises. This way the process can produce all the kinds of organised complexity we see in the living world - yet all it needs is this one simple, elegant, beautiful, and obvious process - natural selection
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