By Zachary Leung
Have you ever thought about your ancestors? Who they were, and where they came from? Arguably, where we come from represents one of the most important questions anyone can ask. Thanks to today’s cutting-edge DNA tests, people can travel back in time to find close relatives, grandparents, and great-grandparents.
The same DNA technology used to determine our ancestry can be used to address the question of humanity’s origin. When and how did our first human ancestors appear? Over the past few decades, scientists have made great strides toward addressing these questions. Putting together genetic, archeological, fossil, and geological evidence, they seem to have arrived at a scientific consensus: our ancestors first appeared in Africa.
The Bible says that humans were created in the Garden of Eden. Bible scholars believe the garden’s location may have been in the Middle East or northeast Africa. Is the scientific consensus incompatible with the biblical account? That is, “in Africa” does not seem consistent with the Middle East or northeast Africa. Before answering this question, let us look at some scientific data. How did our ancestors begin in Africa and, in turn, migrate to different parts of the globe?
Advances in genetics provide a powerful way to explore human origins and migration. Scientists have found that each person’s DNA carries a historical document. By comparing the DNA sequences of human people groups around the world, they gain an understanding of humanity’s origin and migration patterns, including approximate dates for these events.
One such advance comprises the development of myriad genetic comparisons that produce genetic trees, such as mitochondrial DNA and Y-chromosomal DNA. Mitochondrial DNA analysis traces humanity’s maternal lineage that is inherited exclusively from one’s mother. Y-chromosomal DNA traces the paternal lineage that is passed exclusively from father to son. These, and other genetic analyses, have led many scientists to believe that humanity originated in Africa. From an evolutionary perspective, humanity suffered a catastrophic population collapse and went through a genetic bottleneck of several thousand individuals in Africa 200,000 years ago. According to mitochondrial and Y-chromosomal DNA data, humanity migrated out of Africa around 120,000 to 80,000 years ago. They followed the coastal route as a prehistoric superhighway from South Africa across the Middle East, around Asia, to North America, and finally all the way down to the tip of South America—the greatest journey ever made.1
Stable Environments & Reliable Marine Foods at Lower Sea Level
Coastal routes offered many advantages for facilitating human migrations. These advantages included:
- the line of the sandy highway that would allow rapid migrations
- relatively stable environments that would avoid the need for complex clothing and tool adaptations
- availability and reliability of marine foods that would circumvent learning new hunting skills
- steepened downhill slopes that would provide fresh water
- rivers leading to the coasts that would offer rich resources
At the time of migrations, the Ice Age sea level was 350 feet below the present level due to Earth’s water being locked up in continental glaciers. Thus, migrants were able to take land bridges or short sea trips as shown in figure 1.
Figure 1: An Ice Age sea level 350 feet below the present helped human migrants to start in (1) South Africa 200,000 years ago. They then crossed land bridges connecting: (2) Horn of Africa and Arabia Peninsula at Bab-el-Mandeb; (3) Arabia Peninsula and Iran at the Persian Gulf; (4) continental Asia and Indonesia; (5) Papua New Guinea, Australia, and Tasmania; (6) continental Asia and Taiwan; (7) continental Asia and Japan; and (8) Siberia and Alaska at the Bering Sea. They reached (9) Patagonia at the tip of South America 13,000 years ago. The sea trips between islands in Southeast Asia were much shorter than they are today.2
Fossil and Archeological Evidence
In principle, fossil and archeological remains could help document these coastal migration routes. Unfortunately, much of that evidence is unavailable because coastal remains have most likely been washed away by rising seas. However, genetic, fossil, and archeological evidence are available from settlers who decided to move inland, in some instances utilizing riverine routes. These water routes represent secondary migrations that might have occurred when coastal migrants trekked across river mouths and streams, including:
- Tigris-Euphrates leading to Mesopotamia, Persian Gulf, and Eurasia.
- Indus River leading to Pakistan and India.
- Irawaddy River leading to the Himalayan foothills including Cambodia and Mandalay.
- Yellow River and Yangtze River stretching deep into China.
- Fraser River and Columbia River stretching into British Columbia, Washington, and Oregon.
- San Francisco Bay leading into California.
As humans migrated around the world, their population sizes would have been small, about 30 in number. When migrants came across a river or a location rich in resources, most likely some would have decided to settle in that locale, while others would have continued their migration, building up the population size again as they continued. Presumably, this pattern would repeat as the migrating groups continually came across other locations replete with ample resources.
Compatibility with the Bible
If humans were created in the Garden of Eden—possibly somewhere near the Red Sea—do these scientific findings showing that human migration started in South Africa present a problem? That’s a discrepancy of several thousand miles.
What if God created Adam and Eve during the Ice Age when the Persian Gulf and the Red Sea were largely dry? Eden would likely be located at the southeastern part of the Persian Gulf, where all four rivers would come together.3 Thus, humans could have easily walked between the Persian Gulf and Africa via Rub’al Khali at the southern end of Arabia, which was humid and cool at the time, with rivers and streams. Excavations at Jebel Faya in the United Arab Emirates indicate possible occupation 130,000 years ago.4 In other words, it is conceivable that after God created humans in the Middle East, they could have migrated to South Africa before they back migrated and began this long coastal migration.
But what about studies showing that Africans were the most genetically diverse population, and thus, the group with the longest history? It is worth noting that Middle Easterners display the second greatest genetic diversity after Africans.5 In light of this apparent discrepancy, is it possible that the coastal migration from Africa to the Middle East caused the original populations in the Middle East to lose some of their genetic diversity? Being at the intersection of three continents, could intermixing have influenced genetic diversity—making people in the Middle East appear to be less ancient than Africans? Biblical and secular records show that there were massive human movements in the region when (a) Moses brought his people out of Africa; (b) Joshua led the chosen people into the Promised Land; (c) Israelites were invaded and exiled by Assyrians, Babylonians, Persians, Greeks, and Romans over centuries; and (d) a large number of people returned to their homes after many years of diaspora and persecutions. In contrast, Africa (especially South Africa) was relatively secluded allowing its genetic diversity to increase over time. Future scientific research should examine the Middle Eastern populations in detail to account for the possible genetic dilution caused by back migration, invasions, and exiles.
Remarkably, the biblical, genetic, fossil, archeological, and geological records appear to be largely compatible, building confidence in the biblical account of human origins.