Parallels between the proximal-distal development of vertebrate and arthropod appendages: homology without an ancestor?
journal contribution
posted on 2023-06-07, 20:27authored byJose Pueyo-Marques, Juan Pablo Couso
Evolutionary studies suggest that the limbs of vertebrates and the appendages of arthropods do not share a common origin. However, recent genetic studies show new similarities in their developmental programmes. These similarities might be caused by the independent recruitment of homologous genes for similar functions or by the conservation of an ancestral proximaldistal development programme. This basic programme might have arisen in an ancestral outgrowth and been independently co-opted in vertebrate and arthropod appendages. It has subsequently diverged in both phyla to fine-pattern the limb and to control phylum-specific cellular events. We suggest that although vertebrate limbs and arthropod appendages are not strictly homologous structures they retain remnants of a common ancestral developmental programme.