Lineage

Lineage refers to a direct line of descent from an ancestor. The term is used across disciplines to denote ancestral lines in families, societies, species, or institutions. It encompasses genealogical ancestry, evolutionary history, and the documented flow of information or influence through time.

In genealogical use, a lineage traces the transmission of genetic material, surnames, or family ties over generations. Researchers construct family trees or pedigrees that show how individuals are related. Lineages can be patrilineal or matrilineal, and may be organized into broader kin groups such as clans or lineages with shared origin myths or property rights.

In biology, a lineage is a line of descent relating organisms or cells through ancestry. Evolutionary lineages are inferred from phylogenetic analyses, while population genetics describe lineages through haplogroups defined by mitochondrial DNA or the Y chromosome. In development, cell lineage tracing maps divisions from progenitor cells to differentiated cell types.

In data management, data lineage describes the origins, movements, and transformations of data as it passes through systems. Documenting data lineage supports governance, quality control, auditing, and reproducibility by showing how a data item was produced and used.

Lineage also informs cultural practices and legal frameworks. Lineage-based inheritance, titles, or social status may be recognized in some cultures, while others rely on merit or civil law. Lineages can be affected by adoption, marriage, divorce, or intercultural mixing, which may alter claimed descent.

Limitations exist in determining lineage. Records may be incomplete or contested, and genetic evidence can complicate claims due to non-paternity events, population admixture, or mutations. Nevertheless, lineage remains a fundamental way humans categorize ancestry and history.