Monday, December 1st, 2008
This is a very serious question and one which has puzzled me since I was quite young?
Humans come in all shapes and sizes but severe deformities apart they all have a certain basic and common shape. You don't seem to get people with normal bodies and arms/hands extending down to their knees, the outer finger on most hands, the 'little' finger is usally the smallest and no one has legs starting one third down the body, well, not that I know of. You may well say that the genes and/or nutrition control height and build but that isn't answering my question. What I want to know is how and by what mechanism the body decided to stop.
Yes I know the bits don't stop all at once, some are earlier, some are later. But why and by what means did the body decide, 'that's enough for fingers,' when a millimetre or two more or less would have gone unnoticed? Same with noses or most other parts you can think of. And why are we mostly symmetrical? It sure wouldn't be easy if one leg was 6 inches shorter than the other but that only begs the question.
Pituitary growth hormone? I can see that coming in somewhere but its secretions carry on after growth has stopped because it is needed for cell regeneration and the like.
You could cite me all sorts of agents that may have a hand in this but I am back where I started. How did the body know, 'that's it,' and turn off the taps to your bits?
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