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.