phylogenese

Phylogenese, also spelled phylogenesis, refers to the evolutionary development and diversification of organisms or lineages over time, including the origin of new species and the historical relationships among them. It is concerned with how life forms originate, change, and divide into descendant lineages, and with the processes that generate biodiversity. In some usages, phylogenese is used interchangeably with phylogeny, but phylogenesis emphasizes the dynamic process of lineage formation, while phylogeny denotes the historical branching pattern of related organisms.

Etymologically, the term combines Greek roots meaning “tribe” or “race” and “origin” or “birth.” Phylogenesis encompasses the broad scope of evolutionary change from ancestral populations to modern lineages and can be studied at multiple taxonomic levels, from populations within a species to entire clades.

Historically, the concept developed alongside the theory of evolution and the idea of common descent. The modern framework emerged with systematic biology, paleontology, and, more recently, molecular genetics. The late 20th century saw the rise of cladistics and molecular phylogenetics, which use shared derived characters and DNA sequences to reconstruct evolutionary relationships and infer the branching order of lineages. Molecular clocks and statistical models have further refined estimates of divergence times and rates of evolution.

Methods used to study phylogenesis include analysis of the fossil record, comparative morphology, embryology, and, increasingly, DNA and protein sequences. The results are often presented as phylogenetic trees or cladograms, illustrating inferred relationships, rates of change, and patterns such as adaptive radiations, vicariance, and biogeographic histories.