Consider the following assertion In the Pleistocene period either the Yamuna once flowed into the Indus, or the Sutlej flowed int…

Question

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

1. A. 1 only
2. B. 2 only
3. C. 1 and 2
4. D. 3 (Correct answer)

Correct Answer

Option D — D

Detailed Solution & Explanation

The correct answer is Option D.

Key Points

• Explanation: The assertion is a palaeo-drainage hypothesis, and the evidence cited for it is biogeographic.
• Statement 3 is the basis: the same species of river dolphin (Platanista) occurs in both the Indus and the Ganga systems.
• These are freshwater animals that cannot cross the sea, so their presence in two now-separate river systems implies the systems were once connected — supporting the idea that a major tributary shifted between them during the Pleistocene.
• Why the other statements are wrong: The Nadi-Sukta of the Rigveda (Statement 1) is a hymn enumerating rivers in geographical order; it reflects the drainage of the Rigvedic period and is not evidence of Pleistocene shifting.
• Robert Bruce Foote (Statement 2) was a geologist celebrated for identifying India's first Palaeolithic artefact at Pallavaram and for pioneering prehistoric archaeology — not for explorations establishing a Sutlej-Yamuna shift.

Additional Information

• The Gangetic river dolphin is India's National Aquatic Animal, and the Indus river dolphin is treated as its close relative — the very relationship that underpins this hypothesis.