There are two opposing views about origin of modern man. According to one view Homo erectus in Asia were the ancestors of modern man. A study of variation of DNA however suggested African origin of modern man. What kind of observation of DNA variation could suggest this?
- Variation only in Asia and no variation in Africa
- Similar variation in Africa and Asia
- Greater variation in Africa than in Asia
- Greater variation in Asia than in Africa
Answer
(3) Greater variation in Africa than in Asia
Solution
Mutations accumulate in DNA with time, so the oldest population of a species shows the greatest genetic (DNA) variation.
⇒ Populations that migrated out later carry only a part of the original variation (founder effect).
⇒ Greater DNA variation in Africa than in Asia shows that modern man lived longest in Africa and spread from there.
∴ This supports the African origin of modern man (as per NCERT, Homo sapiens arose in Africa and moved across continents).
Answer: (3)