pangenesis

Pangenesis is a historical hypothesis of inheritance proposed by Charles Darwin in 1868 to explain how hereditary information is transmitted from parents to offspring. In Darwin’s view, all parts of the body shed microscopic particles called gemmules, which circulate and accumulate in the reproductive organs to form the gametes. Offspring inherit a composite set of gemmules derived from both parents, and the traits of the body parts are reflected in the inherited material.

According to the theory, gemmules originate from all tissues, including somatic and germ cells, and their combination at conception determines the phenotype of the offspring. Because gemmules could be influenced by environmental conditions affecting the body, pangenesis offered a potential mechanism for the inheritance of acquired characteristics, a concept aligned with some 19th-century debates on how traits are passed down.

Reception and legacy: Pangenesis was influential at the time as Darwin sought a concrete mechanism for inheritance that could interact with natural selection. It was later challenged and largely rejected in the 1880s and beyond. August Weismann’s germ-plasm theory argued that hereditary information is confined to the germ line and that somatic changes do not alter offspring, undermining pangenesis. The rediscovery and elaboration of Mendelian genetics provided a clearer, particulate mechanism for inheritance that did not rely on somatic gemmules.

Today, pangenesis is regarded as an obsolete and speculative model. It is of historical interest for illustrating early attempts to reconcile heredity with evolution and for highlighting the shift from speculative to genetic explanations of inheritance.