Homology in Character Evolution

摘要: Homology forms the basis of organisation for comparative biology. Richard Owen's simple definition homology as ‘same organ in different animals under every variety form and function’ takes on new meaning light Darwin's concept descent with modification. The modern study biology phylogenetics is grounded notion that organisms share a greater proportion homologous (i.e. ‘derived’) characteristics more recently they common ancestor. Instead solely being purview anatomical study, these can be applied at level molecular evolution, genomic evolutionary developmental (‘evo/devo’). Aspects help us formulate hypotheses about changes structures inference evolution all levels biological organisation. Key Concepts: Homology was originally measure correspondence between structures. Descent modification explains result shared ancestry reflects modifications within related lineages. Comparative methods use to infer groups (phylogenetics). Recent advances allow comparison diverse levels, including DNA sequences, arrangements pathways. Recent work highlights fundamental or ancient level, termed ‘deep homology’. Keywords: archetype; evolution; correspondence; gene; morphology; genome; phylogeny; development; deep