Single-step large mutation leading to speciation is also called :

The correct answer is Option (2) → Saltation

Option (1) Founder effect — Incorrect. When a small group drifts away and starts a new population, its changed allele frequencies are the founder effect, a result of genetic drift.

Option (2) Saltation — Correct. Hugo de Vries believed that mutation, not small variations, causes evolution. A single-step large mutation that leads to speciation is called saltation.

Option (3) Branching descent — Incorrect. Branching descent is Darwin's idea that species arise slowly from a common ancestor, like the branches of a tree.

Option (4) Natural selection — Incorrect. Natural selection works on small variations over many generations, not in one large step.

Note: A similar question was also asked in CUET (UG) 2023 on 05-06-2023 (Slot 2).

NCERT Extract:
Mechanism of Evolution – “… In the first decade of twentieth century, Hugo deVries based on his work on evening primrose brought forth the idea of mutations – large difference arising suddenly in a population. He believed that it is mutation which causes evolution and not the minor variations (heritable) that Darwin talked about. Mutations are random and directionless while Darwinian variations are small and directional. Evolution for Darwin was gradual while deVries believed mutation caused speciation and hence called it saltation (single step large mutation).”