monogenesis

Monogenesis is a term used in several disciplines to denote the hypothesis that a complex domain has a single origin. In biology, it most commonly denotes the idea that life originated once from a single ancestral organism, with all current life sharing a common lineage. This aligns with the concept of universal common descent and is supported by shared biochemical features, such as the genetic code, cell structure, and fundamental metabolic pathways, as well as by phylogenetic analyses of diverse organisms. In discussions about the origin of life, monogenesis is contrasted with polygenesis, the idea that life could have arisen multiple times in different environments.

In linguistics and anthropology, monogenesis refers to the hypothesis that all human languages descend from a single proto-language. This Proto-World hypothesis is debated; many researchers view language diversification as more plausibly explained by branching lineages from multiple ancestral languages, or through contact-induced change, convergence, and borrowing that complicate simple trees. Critics note the lack of direct evidence for a single ancestral language and the enormous time depths involved.

Across fields, monogenesis is a theoretical stance about origins and is evaluated by the strength of evidence, testable predictions, and coherence with related data. While strong support exists for a single-origin framework in biology, especially for explaining the relatedness of all life, debates in the origin of language and in alternate origin theories continue to shape the discussion.