UPSC Prelims 2026 · Question 1 of 96
UPSC Prelims 2026 question on Yamuna Sutlej River Capture
- ExamUPSC CSE
- Year2026
- PaperGeneral Studies Paper I
- SubjectAncient History
- TopicConstruction of Ancient History
- DifficultyHard
- TypeStatement
Consider the following assertion:
In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed into the Yamuna and one major tributary of either had shifted from the Ganga to the Indus or vice versa.
Which of the following is/are the basis of the above assertion?
1. The Nadi-Sukta of the Rigveda
2. The explorations of the Sutlej and the Yamuna by Robert Bruce Foote
3. The presence of the same species of dolphins in both the Indus and the Ganga river systems
Select the answer using the code given below:
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Answer: D. 3
Verdict
Only statement 3 is a basis for the assertion, so the answer is Option (d).
Analysis
Statement 3 is a valid biogeographic basis: The South Asian river dolphin, historically classified as Platanista gangetica, exists in both the Ganga river system (India, Nepal, Bangladesh) and the Indus river system (Pakistan). These dolphins are strictly freshwater animals that cannot survive in marine water, and the Indus and Ganga river mouths are approximately 4,600 km apart across the sea, making oceanic dispersal physically impossible. Molecular studies show the Ganga and Indus dolphins diverged approximately 550,000 years ago - squarely within the Pleistocene. One ancestral population colonised both rivers when they were connected and was then separated when river capture events divided the drainage systems. This is the most scientifically accepted basis for the assertion.
Statement by statement
Statement 1 is not a valid basis: The Nadi-Sukta (the 'River Hymn', Rigveda Mandala X) lists the rivers known to the Vedic people from east to west - Ganga, Yamuna, Sarasvati, Shutudri (Sutlej), Parushni (Ravi), Asikni (Chenab), Vitasta (Jhelum) and others. It records rivers as they existed in human memory, not prehistoric drainage shifts. The Rigveda was composed around 1500-1200 BCE, during the Holocene, whereas the Pleistocene epoch ended about 11,700 years ago. The hymn therefore cannot testify to Pleistocene river capture, though scholars do value it for its empirical geographical markers, which delineate a Vedic horizon spanning the Punjab and beyond and inform discussions on the Sarasvati's prehistoric vitality before its aridification.
Statement 2 is not a valid basis: Robert Bruce Foote (1834-1912), the British geologist celebrated as the 'Father of Indian Prehistory', discovered India's first Palaeolithic handaxe at Pallavaram near Madras (Chennai) on 30 May 1863, found stone tools at Attirampakkam in Tamil Nadu, and discovered the Belum Caves in Andhra Pradesh in 1884. He worked primarily in South India and Gujarat - not in the Punjab/UP/Yamuna region - and never explored or mapped the Pleistocene drainage dynamics of the Sutlej and the Yamuna. His work focused on prehistoric stone tools and archaeology, not ancient river capture events. Siwalik stratigraphy and Pleistocene drainage changes in the Punjab region were studied by geologists E.H. Pascoe and G.E. Pilgrim.