Hugo de Vries, working on the evening primrose plant, said evolution happens by mutations: large differences that appear suddenly in a population. He called this single big jump "saltation" (single-step large mutation). Memory hook: "de Vries jumped (saltus = leap) with a BIG, SUDDEN, DIRECTIONLESS mutation, while Darwin walked with small directional steps."
de Vries' saltation: one large sudden random mutation makes a new species in a single jump, unlike Darwin's small directional variations that add up slowly.
Your doubts, answered
What exactly did Hugo de Vries propose?
He proposed the mutation theory. Based on his work on the evening primrose, he said evolution is caused by mutations, which are large differences that arise suddenly in a population. He believed mutation, not Darwin's small heritable variations, drives evolution.
What is saltation in de Vries' theory?
Saltation means a single-step large mutation. de Vries believed that one big mutation could directly cause speciation (a new species in one jump). NCERT states: de Vries believed mutation caused speciation and hence called it saltation (single step large mutation). The word comes from saltus, meaning a leap or jump.
Which plant did Hugo de Vries work on?
He worked on the evening primrose (Oenothera). His observations of sudden large changes in this plant led him to the idea of mutations. Remember this plant name because NEET has asked which organism de Vries studied.
Are de Vries' mutations random and directional or directionless?
According to de Vries, mutations are random and directionless. This is the exact opposite of Darwinian variations, which are small and directional. NEET 2019 tested this exact point.
How is de Vries' idea different from Darwin's?
de Vries said evolution needs large, sudden, random, directionless mutations that cause speciation in one step (saltation). Darwin said evolution happens through small, slow, directional, heritable variations selected over many generations. This contrast is the core NEET difference.
⚠️ The NEET trap ✗ de Vries proposed that evolution happens by multiple small step mutations over a long time. ✓ de Vries proposed a SINGLE-STEP LARGE mutation (saltation). His mutations are big and sudden, not small or multi-step. 🧠 Options often list 'multiple step mutations' or 'minor mutations' as traps. de Vries = single-step + large. The small/directional/gradual words belong to Darwin, not de Vries.
Real NEET questions
2018
According to Hugo de Vries, the mechanism of evolution is
A · Phenotypic variations
B · Saltation ✓
C · Multiple step mutations
D · Minor mutations
Solution: de Vries, based on his work on evening primrose, said evolution is driven by mutations, large differences arising suddenly. He believed a single large mutation could cause speciation, which he called saltation (single-step large mutation). So the mechanism is saltation, not phenotypic, multi-step or minor variations.
2019
Variations caused by mutation, as proposed by Hugo de Vries are
A · random and directional
B · random and directionless ✓
C · small and directional
D · small and directionless
Solution: NCERT states mutations are random and directionless while Darwinian variations are small and directional. So de Vries' mutational variations are random and directionless. The 'small and directional' choice describes Darwin, not de Vries.
Solved Evolution NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
It is Hugo de Vries' idea that evolution is caused by mutations, large sudden heritable differences in a population, rather than by the small gradual variations Darwin described.
What does saltation mean in one line?
Saltation is a single-step large mutation that de Vries believed could directly produce a new species.
Why is de Vries important for NEET Evolution?
Every year NEET asks the de Vries keywords: evening primrose, mutation, saltation, single-step large, random and directionless. These are quick guaranteed marks if memorised.
Did de Vries agree with Darwin?
No. de Vries thought Darwin's small directional variations were too minor to cause evolution; he argued big sudden random mutations were the real driver.
