Innovation and opportunity in the evolution of life
The aim is to produce a complete evolutionary tree of tetrapods and use this to explore two core questions in macroevolution: the balance between innovation and external processes in driving the evolution of life; and, identifying the best model for morphological evolution. Biodiversity today is unbalanced, with a small number of highly successful groups, like birds and beetles, and many others of equal antiquity but with far fewer species. Why are those groups so successful – was it chance or do they have some remarkable adaptation(s)? The core of the project is to construct a complete evolutionary tree of all 30,000 living species of tetrapods (amphibians, reptiles, birds, mammals) and add the 10,000 fossil species; this will generate a database of key characters, the homologies, shared by major groups. The probability of different drivers of diversification will be tested, focusing on those key, highly successful groups (e.g. lizards, birds, neornithines, passerines, rodents) that show explosive evolution to very high species diversity. The proposal goes to the roots of macroevolutionary understanding, and encompasses key questions about origins and modern biodiversity. The project is ambitious, but is possible because of advances in knowledge of relationships of all key tetrapod groups based on phylogenomic and morphological data, increasing precision of geological dating, and the availability of a range of computational methods to construct large phylogenetic trees, to assess likelihood of trees, to explore innovation and evolutionary rates and models, and Bayesian modelling techniques that can map trait data onto large trees and evaluate multiple models of drivers and bias. A unique outcome will be the chance to explore waiting time between major morphological changes, assessing distribution and magnitude, and use this information to inform the construction of a meaningful model of morphological evolution for computational phylogenetics.