Don't forget the Gompertz function[1], used to model population growth:<p>$$ g(x) = a e^{-b e^{-cx} } $$<p>[1]: <a href="https://en.wikipedia.org/wiki/Gompertz_function" rel="nofollow">https://en.wikipedia.org/wiki/Gompertz_function</a>
My fave,<p><a href="https://en.wikipedia.org/wiki/Sigmoid_colon" rel="nofollow">https://en.wikipedia.org/wiki/Sigmoid_colon</a>