A long, long, long time ago, everyone was from Africa. Once, we were Homo erectuses, then we evolved into Homo heidelbergensis, & then we evolved into Homo sapiens. That's a simplified evolutionary story of humans. Then Homo sapiens evolved into many different races and sub-races due to the people being spread across different environments and developing various cultures.
Today, we have blacks (black Africans, black Australian natives, & native blacks in Southeast Asian islands), Middle Easterners (Arabs, Semites, Iraqis, Persians, Syrians, etc), Europeans (Greeks, Spaniards, Germans, Swedes, etc), South Asians (Pakistanis, Indians, Bangladeshis, etc), East Asians (Chinese, Mongolian, Korean, Japanese, etc), Southeast Asians (Vietnamese, Philippines, Indonesians, Pacific Islanders, etc), and Native Americans (North American natives, Central American natives, & South American natives).
It's a good thing Eurasians evolved light skin, straight hair, better facial and body proportions, and higher intelligence. Otherwise, we would not be communicating with each other on the Internet about cool military technology and plans.
If Eurasians did not evolve into existence, then we would be too busy hunting and gathering due to crude agriculture, being ignorant of modern languages (a complete communication system for reading, writing, & speaking), dying of simple infections, struggling to understand math and science, running around semi-naked, and displaying backward fashion values like the relatively primitive blacks in Africa, black natives in Australia, and black natives in Southeast Asian islands like Papua New Guinea.
Your understanding of Human genetics is outdated. Australian natives and 'Black' South east asians (LOL) are closely related to East Eurasian populations than to Africans. In fact, an Nigerian is closer to an Native American on Fst distance table than to an Micronesian native who happens to have dark pigmentation like most SS. Africans. This is because modern Europeans/Middle-Easterners, East Asians and Amerindian only split away from Africans (not all africans) around 60-45,000 years ago, while the split between Australian/Pacific islanders is between 120-90,000 years ago. And there has been constant gene flow between OOA and African populations in the past 25,000 years. East Africans migrated to middle-east and europe and spread the E1b1b1b and T1 haplogroup genes to West Eurasian populations while West Eurasian migrated to Africa, spreading R1b in N. central African populations and J1 and j2 genes in East Africa and N.Africa. Some theorist say that the sharp features of modern Europeans (and M. Easterners) is the result of admixture between 'Basal' Eurasian (originated in the Red Sea, in modern Eritrea) and the ancestor of Middle Eastern farmers who migrated to Europe to mix with the native WHG (West Eurasian hunter gather) population who possessed more robust and round in facial symmetry than modern europeans. Real Europeans probably looked more Cro-Magnon (Robust) or khanty.
Modern East Asians are not some pure 'Mongoloid' population as one may think. Australiods lived in much of modern China and were the first Homo Sapiens in East Eurasia (Homo Erectus were first 'hominids' in Asia). They mixed heavly with those Australoids, esp in Japan and SEA Asia. It is often though that Japanese or N.Chinese were the pure 'Asians' while the SE. Asian combodian and Thais were more ad-mixed, but genetic again showed this to be false as Japanese are by far the most ad-mixed and Australoid Asians by far. The ancestors of Modern Asians only recently spit from Europeans and other west Eurasian population in central asia (35,000 years ago) and looked Middle Eastern/Ameridian untill the last 11,000, where they lost body hair, looked more Neotonized and have eye folds smaller than most human populations (like the San). This is in response to the changing dry environment of Western China during the last stages of the Ice age, just like how the Khoi-San looked Neotonized in response to the change in the environment in S.Africa (became Drier). So any linking between the looks of Asians and San people due to mixing is quite dumb. It is nothing more than an example of convergent evolution between two different human population. Just like how both E.Africans and N.Europeans have evolved lactose persistence genes to digest milk after the neolithic.
And if your are trying to link phenotype to civilization and then your clearly need to brush up on your knowledge of history. 'Eurasia' is random concept. Malays under the gupta empire of the Chola empire are not gonna have similar phenotypes or cultural norms as the Germanic tribes of the classical era despite both being OOA populations. The Sudan has far more written and achelogical record that is more advance than Scandinavia.