Time travel had a big effect.
During the Ice Age, lower sea levels created land bridges between continents, like the Bering Land Bridge between Asia and North America. This allowed early humans to migrate to new continents in search of food and resources.
Early humans likely reached the continent of South America last, as evidence suggests they migrated there around 15,000-20,000 years ago. This migration is believed to have occurred via the Bering Land Bridge which connected Siberia to Alaska during the last Ice Age.
Approximately 40,000 years ago, humans reached the continent of Australia. They are believed to have arrived there via watercraft from Asia.
Africa.
Early humans first appeared in Africa. The oldest known fossils of early human ancestors, such as Ardipithecus and Australopithecus, have been found in East Africa, indicating that Africa is the continent where early humans originated.
Most scientists believe that humans originated in Africa.
land briges
Reduced sea levels, caused by water evaporating from the oceans and being locked up on the continents in the form of ice. Many areas of previously shallow seas were now dry land.
To go from one continent to another, humans had to travel by foot or by horse. Unless, of course, there was water in between. The invention of ships made it possible to go between continents.
land bridges
To go from one continent to another, humans had to travel by foot or by horse. Unless, of course, there was water in between. The invention of ships made it possible to go between continents.
To go from one continent to another, humans had to travel by foot or by horse. Unless, of course, there was water in between. The invention of ships made it possible to go between continents.
To go from one continent to another, humans had to travel by foot or by horse. Unless, of course, there was water in between. The invention of ships made it possible to go between continents.
Humans travel to and from the Antarctic continent when it is accessible either by ship or by airplane. During the winter season -- when the sun isn't shining, the continent is not accessible.
climate, food and hunting
parasite
Humans do not inhabit the continent of Antarctica permanently, but there are settlements there where teams of scientists study aspects of the great frozen continent.
Some of them are not all of them are caused by humans