[mamelukesabre]

nonsense. All mammals are domesticable if you put in the time and effort with a breeding program. Hand carts are pulled by humans. No animals required.

[Harmless Teddy Bear]

And hand cart appear long after animal pulled carts do. It's the way it works. Wheelbarrows didn't appear in Europe until 1000 AD.

As to all animals being capable of being domesticated... ok, be sure explain how to Sigfried and Roy.