De Vries looked for evidence of mutation extensive enough to produce a new species in a single generation and thought he found it with his work breeding the evening primrose of the genus Oenothera, which he started in 1886.
De Vries buscou as evidencias de mutacións o suficientemente amplas como para poder producir novas especies nunha soa xeración e pensaba que as encontrara nos seus traballos de investigación sobre a planta Oenothera, que empezaron en 1886.