Open Access

Existence Of A Latent Developmental Program: Revisiting The Universal Genome Model Of Evolution Of Metazoa


In 2007, I published a hypothesis about mechanisms of evolution of large taxonomic groups of the Kingdom Animalia, which was based on advances in paleontology genome analysis, genetics and embryology that are difficult to understand within Darwinian intuition. According to this model that I called a Universal Genome hypothesis: (a) the Universal Genome that encodes major developmental programs essential for various phyla of Metazoa emerged in a unicellular or a primitive multicellular common ancestral organism shortly before the Cambrian period; (b) The Metazoan phyla, all having similar gene sets, are nonetheless very morphologically distinct because each utilize specific combinations of developmental programs. A highly counterintuitive prediction of this idea, which strictly dissociates it from the classical evolutionary model, is that latent developmental programs should exist in genomes of lower Metazoan taxa. These latent programs control the development of organs and other morphologies that would emerge in evolutionary higher taxa. Potentially such programs could be activated by mutations or application of signaling molecules, and thus be revealed in lower taxa. A paper on the embryology of fins published in the Cell journal provides an evidence for existence of such a latent developmental program. Here I comment of this discovery and its implication in our understanding of evolution.