Hi guys,

I was trying to come up with a helpful analogy to help explain natural selection in simple terms and it occurred to me that the game Hangman might make a useful analogy, albeit an imperfect and simplified one. I'd be interested to hear your thoughts on this and any other useful analogies or strategies for explaining in simple terms how natural selection allows complexity to arise from simplicity and how it is distinct from random chance.

The Hangman analogy I propose would read as follows:

A long word is chosen, say with a dozen letters, and a dozen blanks are drawn on the paper. Person A then guesses a letter. If the letter is present in the word a blank is filled in and the player can try another letter and so on. Their further guesses will be informed by the letters they have already discovered rather than being completely random. If the letter is not present the player loses a life (represented by the drawing of part of the gallows). If they run out of lives the game is over and a new player, Person B takes their place. Person B must start from the beginning.

In this analogy the long word is a complex adaption, requiring many seperate chance mutations to build it. Each guessed letter is a chance mutation that can be beneficial (correct answers bring you closer) or detrimental (wrong ones cost you lives). The loss of all lives represents the extinction of the species, meaning no further mutations can occur. Person B is an entirely different species that can't "compare notes" with Person A and hence must start from the beginning (though they may take a different route).

The benefit of this analogy is it's an example of random guesses still having a sense of forward progression (discovered letters are not removed, and gradually build up), and that it refers to a simple game I think most people will be familiar with. You could then go on to explain how a complex adaption takes many more than a dozen steps, that there are many more than 24 possible mutations, and that each guess takes many generations, to give a sense of the timescales involved.

The weaknesses are considerable and include the inability to go backwards (beneficial changes can be lost as well as gained) and the existence of a single specific end goal (the unknown word), rather than this being a continual process without set targets. It also ignores the possibility that a beneficial mutation does not spread throughout the species.

I very much doubt this is an original suggestion, but it seemed a handy simplification of the "password-guessing" analogy I was just reading about in Dawkins' "The Blind Watchmaker". Any comments or alternative methods would be welcome (I'm still not very widely read on the subject of evolution so I'm sure others have put it more clearly than I could).

Thanks for your time.

David