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:

  • 1 only
  • 2 only
  • 1 and 2
  • 3

Answer: (d) 3

  • Statement 1 is incorrect (Contextual Mismatch):
    • The Nadi-Sukta hymn in the 10th Mandala of the Rigveda lists around 19 rivers (including the Ganga, Yamuna, Sarasvati, Sutlej, and Indus) in a geographical sequence from east to west. While it proves the Vedic people knew these rivers, a text composed in the 2nd millennium BCE cannot serve as the geological scientific basis for river channel migrations that occurred during the deep-time Pleistocene period (which ended roughly 11,700 years ago).
  • Statement 2 is incorrect (Historical Figure Mismatch):
    • Robert Bruce Foote is universally recognized as the “Father of Indian Prehistory” because he discovered the first Palaeolithic stone tool (a handaxe) at Pallavaram near Madras in 1863. His work was focused on prehistoric human tool cultures and stratigraphy, not the fluvial geological mapping of the Indo-Gangetic drainage divides in northern India.
  • Statement 3 is correct (Biological/Geological Evidence):
    • The Indus river dolphin (Platanista gangetica minor) and the Ganges river dolphin (Platanista gangetica gangetica) are subspecies of the same freshwater cetacean. Because these mammals cannot survive in salt water, their presence in two entirely separate modern drainage systems proves that a freshwater connection must have existed between the Indus and Ganga basins during the Pleistocene epoch, enabling a single ancestral population to split when the Yamuna/Sutlej channels diverted.

Paleohydrology & The Indo-Brahma River Hypothesis

  • The Theory: Proposed by geologists E.H. Pascoe and G.E. Pilgrim; posits that a single, massive, westward-flowing river system (Indo-Brahma or Siwalik River) existed during the Tertiary to Pleistocene epochs, draining from Assam to the Arabian Sea.
  • The Disruption: Tectonic upheavals during the mid-Pleistocene period uplifted the Potwar Plateau (Pakistan) and the Delhi-Aravalli Ridge (India).
  • The Result: This drainage divide split the unified system into two separate entities: the Indus system flowing westward to the Arabian Sea, and the Ganga-Brahmaputra system flowing eastward to the Bay of Bengal.
  • River Piracy (Capture):
    • The Sutlej originally flowed eastward into the Sarasvati/Yamuna system before tectonic tilting diverted it westward into the Indus.
    • The Yamuna originally flowed westward into the Indus/Sarasvati channel before being captured by the Ganga system via headward erosion.

South Asian River Dolphins (Platanista)

  • Taxonomy: Recent genetic divergence data indicate that the Ganges River Dolphin (Platanista gangetica) and the Indus River Dolphin (Platanista minor) split into distinct species approximately 550,000 years ago during the Pleistocene epoch due to river network separation.
  • Biological Evidence: Both species are strictly freshwater cetaceans and functionally blind. They are physiologically incapable of navigating marine/saline waters. Their presence in two disconnected drainage basins serves as definitive biological proof of a prehistoric, contiguous freshwater link between the Indus and Ganga basins.
  • Ganges River Dolphin (Platanista gangetica):
    • Legal Status: National Aquatic Animal of India.
    • IUCN Red List: Endangered.
    • WPA 1972: Schedule I.
    • CITES: Appendix I.
    • Key Indicator: Acts as an umbrella/indicator species for the health of the entire river ecosystem.
  • Indus River Dolphin (Platanista minor):
    • Legal Status: State Aquatic Animal of Punjab (India).
    • IUCN Red List: Endangered.
    • Distribution in India: Exclusively confined to an isolated population in the Beas River (Beas Conservation Reserve, Punjab).

Chronology of Ancient Historical Geography vs. Geological Epochs

  • Geological vs. Historical Mismatch: Human literary and historical records cannot serve as empirical scientific evidence for mid-Pleistocene geomorphological transformations.
  • Pleistocene Epoch: Lasted from roughly 2.58 million years ago to 11,700 years ago; characterized by repeated glacial cycles and major tectonic river-diversions.
  • Holocene Epoch: Current geological epoch starting around 11,700 years ago; encompasses all written human history, including the Vedic Period.
  • The Nadi-Sukta (Rigveda):
    • Location: Contained within the 10th Mandala (Hymn 75) of the Rigveda.
    • Chronology: Composed around 1500–1000 BCE (Late Bronze Age/Holocene).
    • Content: Geographically enumerates roughly 21 rivers in a strict East-to-West sequence, beginning with the Ganga, moving to the Yamuna, Sarasvati, Sutlej (Sutudri), Ravi (Parushni), and terminating at the Indus (Sindhu) and its western afghani tributaries.

Pioneers of Indian Archaeological and Geological Surveys

  • Robert Bruce Foote:
    • Title: Known as the “Father of Indian Prehistory”.
    • Key Discovery (1863): Unearthed the first definitive Palaeolithic (Old Stone Age) tool in India—a quartzite handaxe at Pallavaram near Madras (Chennai).
    • Domain: Affiliated with the Geological Survey of India (GSI); his work centered on stone tool typologies, prehistoric stratigraphy, and laterite formations in Southern and Western India, not North Indian paleohydrology.
  • Comparative Pioneers for Elimination:
    • Alexander Cunningham: First Director-General of the Archaeological Survey of India (ASI, 1861); focused on historical archaeology and identifying ancient sites using Chinese pilgrim travelogues (Faxian/Xuanzang).
    • Sir Mortimer Wheeler: Director-General of ASI (1944); introduced the scientific stratigraphic method of excavation to Indian archaeology (notably at Harappa and Arikamedu).