Mechanism of evolution?

Mechanism of Evolution

Populations evolve, but individual organisms do not. A population is an interbreeding group of individuals of one species in a given geographic area at the same time. A population evolves because the population contains the collection of genes called the gene pool. As changes in the gene pool occur, a population evolves.

• Hugo de Vries worked on evening primrose. He gave the idea of mutations.
• Mutation is the difference arising suddenly in a population. Hugo de Vries theory of mutation differs from Darwin
• He stated that mutation causes evolution and not the minor variations that as suggested by Darwin.
• Mutations are sudden, random and directionless while Darwinian variations are small and directional.
• Evolution according to Darwin was slow and gradual whereas Hugo de Vries believed that mutation caused large changes that led to speciation. He therefore called it is saltation (single step large mutation).
• Saltation: It is a large and an abrupt evolutionary change that has been brought about due to sudden large-scale mutation.