Why do natural, biological shapes tend to be cylindrical, spherical and conical?
For example:
Cylindrical: Pretty much everything. Arms, legs, the spine, the middle section of branches
Spherical: Cells, eggs laid in water
Conical: Shoots, parts of trees

Why do fingers have smaller distances between the joints as you get to the finger tips?

Why do crabs have hard outer shells whereas fish don't? How does this allow them to do things that fish can't and how does the lack of shell let fish do things? Why don't crabs have harder outer shells like mussels or clams? Whatever happened to bony fish? They're fish, but they're bony.

Are there shapes other than cylinders, spheres and cones that are common in nature? Why?

Why are ear holes circular? Why is the ear canal circular? Why are pores circular?

Why do most starfish have five arms?

Why do Caucasians have big noses and Siberians/Canadian Amerinds not?

Why did the Australian Aboriginal face develop differently from the African face?

And, why not:

BIOLOGY AND SCIENCE QUESTIONS GENERAL