Which of the following phenomena might have influenced the evolution of organisms? (1). Continental drift (2). Glacial cycles Select the correct answer using the code given below.

Both phenomena are correct, so the answer is C. The question asks what 'might have influenced' evolution, a loose standard that both clearly meet, because each changes where organisms live and how populations stay cut off from one another.

• Statement 1 (Continental drift): The breakup of Gondwanaland isolated populations on separate landmasses. Australian marsupials and the flightless ratites of the Southern Hemisphere are classic examples of allopatric speciation. Drift also reshaped ocean currents and regional climates.
• Statement 2 (Glacial cycles): Pleistocene glaciations, paced by Milankovitch cycles, lowered sea levels and exposed land bridges such as Beringia, allowing dispersal. They also pushed species into refugia, forced range shifts and extinctions, and changed selection pressures.

Option A ignores the climatic driver, B ignores the tectonic driver, and D denies both, which the biogeographic evidence does not support. The core concept is that environmental change creates geographic isolation and new selection pressures, the engine of speciation. For Mains (GS-III, environment and biodiversity), this links directly to how present-day climate change is shifting species ranges.

Trap: Students either assume evolution happens only through selection in a stable environment, or they pick the one option they recognise best and stop there.