Why does the hair on your head keep growing to an indefinite length, but some other hair stops at a certain length?
Take your eyebrows for example. If you pluck your eyebrows, they grow back quickly. But it never gets so long that it is hanging in your eyes...
Why indeed...
2 comments:
pretty sure some sort of gene expression involved...hehe
That's a good question! I'd never thought of that....
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