What difficulties did early humans face in migrating to Australia and the Americas and what are the theories about how they overcame those difficulties?
http://en.wikipedia.org/wiki/Early_human_migrations
http://en.wikipedia.org/wiki/Human_migration#Pre-modern_migrations
Think about small boats, storms, rudimentary navigation, food, and especially fresh water.
Early humans faced several difficulties in migrating to Australia and the Americas. One key challenge was the geographical distance and physical barriers they encountered during their migrations. For Australia, the main obstacle was the vast expanse of ocean that separated it from Southeast Asia. In the case of the Americas, the Bering Strait served as a land bridge that early humans had to navigate in order to reach the Americas from Asia.
Several theories have been proposed regarding how early humans overcame these migration difficulties:
1. Coastal Migration: One theory suggests that early humans might have used boats or rafts to navigate along the coastlines of Southeast Asia, island-hopping their way to Australia. This would have allowed them to gradually move towards Australia while staying close to the shore and utilizing marine resources for sustenance.
2. Overland Migration: Regarding the Americas, a prevailing theory is the Bering Land Bridge hypothesis. It suggests that during the last Ice Age, when sea levels were lower, a land bridge—known as Beringia—existed between Siberia and Alaska. It is hypothesized that early humans traveled across this exposed land bridge and gradually moved southward into the Americas.
3. Island Hopping: Another theory posits that early humans might have populated the Pacific islands between Southeast Asia and Australia by intentionally or accidentally venturing onto small islands. From there, they could have continued their migration via a series of island-hopping, using natural resources and reaching Australia over time.
4. Maritime Skills: It is plausible that early human migrants possessed advanced maritime skills, allowing them to navigate open waters and undertake long-distance sea voyages. Techniques such as celestial navigation, knowledge of ocean currents, and the ability to construct seaworthy vessels would have been crucial in overcoming the challenges of crossing vast expanses of ocean.
It is important to note that these theories are based on archaeological evidence, fossil records, genetic studies, and computer simulations. However, the exact details of early human migration are still the subject of ongoing research, and further discoveries may refine our understanding of how they overcame these challenges.