Some of the results seemed peculiar , though : why had the natives of North America taken rattlesnakes , but not horses , wondered Sir Thomas Browne in 1646 ? The obvious answer was that man had spread over the continents following the destruction of the Tower of Babel and taken animals with him , yet some of the results seemed peculiar : why had the natives of North America taken rattlesnakes , but not horses , wondered Sir Thomas Browne in 1646 ?