If the different breeds of humans have stayed separated like Tigers (Bengal, Siberian, South China, Indochinese, Java, Bali, Sumatra, Malayan & Caspian Tiger), Lions (African lion, white lions,Indian lions (Asiatic), European lions extinct, & American Lion extinct), Leopard (African, Arabian, Persian, Amur, Indian, Sri Lankan, Indochinese, Javan, Anatolian), Brown Bears (Eurasian, Kodiak, Himalayan, Kamchatka, East Siberian, Ussuri, Tibetan Blue, Gobi, Syrian, Sitka, Stickeen, Marsican Grizzly, Peninsular Grizzly, Californian Grizzly, Mexican Grizzly,) American Black Bear (subs: Spirit & Cinnamon Bear) & foxes then we'd probably be on our way of becoming separate species. I like to think that Humans being separated by different land mass environment triggered the start to being a separate species as we changed in skull/facial structure, hair, skin color & height as sub Species which can interbreed.
I believe there are 5, if not 8, sub species of humans each having branches of different breeds or tribes.
Caucasian breeds: Europid: Scandinavians, Finns, Rus, Celts: Scotts, Welsh, Irish, Germanic: Angles, Saxons, Teuton, Goth, Vandals, Lombard, Prussia, Italic (Latin): Galician, Lusitania, Andalusia, Italy, Eastern European: Slavic, Czech, Ukraine, Romania, Uzbeks, Armenians, Circassian, Baltic States, Greece, Macedonia, Asiatic Caucasoid: Persian, Huns, Azerbaijan, Turks, Semites (Hebrews & Arabs) Afghans.
Congoids (sub Saharan): Neolithic, Bantus, & Pygmies, Capoid (a sub Branch or Separate): Khoi, San.
South Asians: Indian, Bangladesh, Pakistan, Sri Lanka, Nepal,
Australoid (either a sub Branch of South Asians or Separate): Dravidian, South Pacific Aborigines: Australia, Melanesia, Papua New Guinea, Fijian, Vanuatu, Philippines...
Mongoid: Orientals: Han, Hmong, Manchu, Qin, Chu, Wei, Sao, Yue, Nippon, Ainu, Korea, Mongol, Siberian: Tuvans, Chukchi, Evenks, Mansi, Nenets, Inuit, Eskimo, Himalayan, Bamar, Indochinese: Khmer, Laos, Siam,
Amerindian a Sub-Branch of Mongoids: Northern Amerindian: Iroquois, Navajo, Nez Perce, Cherokee, Seminole, Lakota... Carib Amerindian: Mayan, Arawak, Taino... Central Amerindians Mayan, Pipil, Xinca, Miskito, Pech, Sumos, Tolupan, Lenkas, Mayangna... Southern Amerindian: Mapuche, Xingu, Quechua, Muisca, Incan...
Austronesian a sub-branch of Mongoids: Malaysian, Indonesian, Philippines (Malayan), Micronesian, Polynesian, Paiwan, Bunun, Amis...
Separating into different species to me is diversity. Wildlife Biologist are trying to keep different species of Big Cats, Bears, Wild dogs, wild small cats, etc. from hybridizing to ensure the diversity & survival of each wild species.