What is the Sahara Pump Theory?
Q: What is the Sahara Pump Theory?
A: The Sahara Pump Theory is an attempt to explain how plants and animals from Africa moved into the Middle East, Europe, and Asia. It suggests that during wetter periods in Africa, migration along river corridors was possible due to larger lakes and rivers existing in the area.
Q: What caused changes in the type of animals found in the area?
A: Changes in the type of animals found in the area were caused by African rainy periods associated with a "wet Sahara" phase which allowed for larger lakes and more rivers to exist.
Q: When did migration along river corridors halt?
A: Migration along river corridors halted when, during a desert phase 1.8-0.8 million years ago, the Nile ceased to flow completely and possibly flowed only temporarily due to Nubian Swell uplift.
Q: How does this theory explain human emigration from Africa?
A: This theory explains human emigration from Africa by suggesting that during wetter periods of a wet Sahara, flora and fauna become common while during dryer periods they retreat northwards or eastwards into different climates which forces them to adapt and possibly gives rise to speciation (species splitting).
Q: How many waves of human emigration has this theory been used to date?
A: This theory has been used to date four waves of human emigration from Africa.
Q: What happens when evaporation exceeds precipitation?
A: When evaporation exceeds precipitation, water levels in lakes like Lake Chad fall and rivers become dry wadis.
