Darwinian/Hennigian Systematics and Evo-Devo: The Missed Rendez-Vous

EvoDevo called homeotic genes “architect genes” because they “control” “body plans”. Using such ordering causal factors, mainstream EvoDevo stayed outside Evolution because in biology, order is not causal, it is a consequence that we need to explain. Natural selection is the concept explaining the rise of apparent order, or regularities. Genes do not control anything, they just impulse. The two pillars of evolutionary theory - descent with modification and natural selection- do occur within the organism itself and the name for it is ontophylogenesis: development and evolution are a single, continuous process. It should have been EvoDevo. To study ontophylogenesis and developmental heterochronies among species, we propose a hierarchical analysis of their ontogenetic time. With a parsimony analysis of a matrix where “operational taxonomic units” are species at a given ontogenetic time segment and characters are organs or structures which are coded present or absent at this time, we show that the hierarchies obtained have both very high consistency and retention index, indicating that the ontogenetic time is correctly grasped through a hierarchical graph. We consider such graphs as real phylogenies and the very core of EvoDevo. This allows to formally detect developmental heterochronies and might provide a baseline to name early life stages for any set of species (where terminologies previously used were different across species) following hennigian principles. Our phylogenetic segmentation of ontogenetic time depicts ontophylogenesis.