As I've said before, "science

As I've said before, "science" can refer to several things, but the two that get mixed up here are (1) the scientific mode of thinking / the scientific worldview, and (2) the institutions of modern science. It's hard to separate the two.

Science is not empiricism. Empiricism is a part of science, but they are not the same since science also includes elements of rationalism and relies heavily on some assumptions that are not empirical realities and/or knowable through empiricist methods. I explain this in The Revolutionary Importance of Science. Basically, science has a bunch of assumptions that we can be moderately sure are true (like materialism and possibly even realism), mostly because of its success, but not totally, and that will probably never change.

Also, although it can't quite be said that HGs PRACTICE science, scientific methods and thinking do clearly have root in human nature. See, for instance, "The Art of Tracking and the Origin of Science" at http://www.cybertracker.org/tracking/tracking-books/276-the-art-of-track..., and also Diamond & Dunbar's examples of the striking similarity of HG taxonomy and modern scientific taxonomy. Dunbar's book is "The Trouble with Science" and Diamond's article is "Zoological classification system of primitive people" at http://www.ncbi.nlm.nih.gov/pubmed/17739593.