Rolling Animals - Notes

Notes

1.^ Although evolutionary and developmental constraints preclude the possibility of a wheel as part of an organism, they do not preclude the use of foreign objects as "wheels", either instinctually (as in the case of the dung beetles discussed above), or through intelligently directed tool use (as in human technology).
2.^ Wheels can be considered to fall into two types: passive and driven. A passive wheel simply rolls freely over a surface, reducing friction when compared with dragging. A driven wheel is powered, and transmits energy to the surface as a means of generating locomotion.

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