There's a lot to be said for convergent evolution, sure, but there's a similar "convergent invention" whose progress does not tick in ice ages. For instance, p

There's a lot to be said for convergent evolution, sure, but there's a similar "convergent invention" whose progress does not tick in ice ages. For instance, pretty much every human civilization invented the spear and the bow, but the Native Americans, although they had wheels such as the circular Mayan calendar and the various hoops used for games, did not use them for transportation (i.e. wheelbarrow or cart) seemingly because they had no domesticated oxen or horses to pull them with. Lacking one necessitated the withering of the other.