Problem was not the people, but the animals Once contact was made, diffusion quickly took place. Peoples throughout the globe have tamed animals as pets. Repeated domestication of the same species in different areas. Modern efforts to domesticate attractive species have failed. No carnivore has been domesticated.
Humans can effectively function as the leader.
Cats are problematic. All Southwest Asia s founder crops preempted independent domestication elsewhere because of the speed of diffusion. Similar latitude, length of day, seasonal variation. Domesticated animals present a similar story. Mexican squash, corn, beans took several thousand years to reach the US Southwest.