Actually, "beast tribe" has less to do with species than you'd think. It's a designation created by the Garleans in reference to their religious practices, and more akin to a derogatory racial term than an actual differentiation between species.
I think it's reasonable to assume at least four out of the five playable races are hominids, but they're not the same species. There's no viable interbreeding, and enough physiological differences for them to have separated enough as to be different species. But they can still be "human" by way of common culture, rather than genetics.
I think it's reasonable to assume at least four out of the five playable races are hominids, but they're not the same species. There's no viable interbreeding, and enough physiological differences for them to have separated enough as to be different species. But they can still be "human" by way of common culture, rather than genetics.