UPSC Prelims 2019 Q92: Science & Technology – Biology
- (a) fossils of a kind of dinosaurs
- (b) an early human species
- (c) a cave system found in North - East India
- (d) a geological period in the history of Indian subcontinent
Answer: (b) an early human species
Explanation
Denisovans: Extinct Hominin Species
| Option | Claim | Verdict | Detail |
|---|---|---|---|
| (a) | Dinosaur fossils | Wrong | Denisovans are not dinosaurs. |
| (b) | Early human species | CORRECT | Denisovans (Homo denisova) are an extinct species of archaic humans, related to but distinct from Neanderthals. First identified in 2010 from finger bone found in Denisova Cave (Siberia, Russia). DNA analysis shows they interbred with modern humans - contributing 3-6% of DNA to modern Melanesians and 0.2% to Asians. |
| (c) | NE India cave system | Wrong | Denisova Cave is in Siberia (Russia), not India. |
| (d) | Geological period | Wrong | Denisovans are a species, not a geological period. |
Answer: (b) an early human species.
Why each option is right or wrong
- (a) Incorrect. Denisovans are hominins, not dinosaurs.
- (b) CORRECT. Denisovans (Homo denisova) are an extinct early human species discovered in 2010 from bones found in Denisova Cave (Altai Mountains, Siberia). Related to Neanderthals; interbred with modern humans.
- (c) Incorrect. Denisova Cave is in Siberia, not NE India.
- (d) Incorrect. Denisovans are a species, not a geological period.
Key point
Denisovans = extinct early human species (Homo denisova). Discovered 2010, Denisova Cave (Siberia). Interbred with modern humans - contribution to Melanesian, Papuan, Aboriginal Australian DNA.
Remember
'Denisovans' refers to an extinct early human species (Homo denisova), first identified in 2010 from bones in Denisova Cave (Altai Mountains, Siberia). They are closely related to Neanderthals and interbred with modern humans - their DNA persists in modern Melanesians (3-6%), Aboriginal Australians, and to a lesser extent in Asians.
Common mistakes
- Confusing Denisovans with Neanderthals - both extinct human relatives but distinct species.
- Assuming any 'ova/ovan' name is Russian region - Denisova Cave is Siberian.
- Not knowing Denisovan ancestry gave modern Tibetans high-altitude adaptation (EPAS1 gene).
Exam tip
Hominin family: Homo sapiens (modern humans) + extinct: Homo neanderthalensis (Neanderthals), Homo denisova (Denisovans), Homo erectus, Homo floresiensis (Flores Hobbits), Homo naledi. Modern humans carry small % of Neanderthal + Denisovan DNA.
Sources
- Nature (2010) - The Denisova Cave discovery paper by Reich et al.
- Max Planck Institute for Evolutionary Anthropology - Denisovan research