Pleistocene Drainage and River Migration

GeographyGeomorphology & Earth ScienceStatement-based● HardStatic

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?

1The Nadi-Sukta of the Rigveda

2The explorations of the Sutlej and the Yamuna by Robert Bruce Foote

3The presence of the same species of dolphins in both the Indus and the Ganga river systems

Select the answer using the code given below:

Options

1 only

2 only

1 and 2

Answer

Explanation

The correct answer is 3. Zoologists and evolutionary geologists use the presence of closely related platanistoid river dolphins (the Indus river dolphin, Platanista gangetica minor, and the Ganges river dolphin, Platanista gangetica gangetica) in two completely separate drainage networks as biological proof of a past interconnected migratory pathway. This indicates that a major tributary linked the two systems during the Pleistocene epoch before tectonic movements uplifted the Delhi-Ambala ridge. The Rigveda's Nadi-Sukta (1) maps early text arrangements but doesn't serve as geological proof for Pleistocene events. Robert Bruce Foote (2) focuses on prehistoric stone tools rather than hydrological mapping of the Indus-Ganga link.

The presence of identical freshwater dolphin species across the Indus and Ganga basins serves as strong biological proof of ancient connected river pathways before tectonic splits.