OriGAMA · Origin of Animals using high-quality Genomic Assemblies and Metagenomic Analyses

One of the most fundamental questions in evolutionary biology is centred on our ancestors: How did animals originate? Recent advances in various disciplines have refined this question of whether the most profound divergence in the animal phylogenetic tree, estimated to have occurred approximately 800 million years ago, was between the sponges (Porifera) or the comb-jellies (Ctenophora), and this remains a contentious point of discussion within the scientific community. This is important as it influences our understanding of the evolution of the nervous, muscular and digestive systems. Did the ancestor of all animals already possess complex systems, or did these systems evolve at a later stage? The project described in this proposal aims to answer this question through multiple crucial steps, firstly by improving the genomic quality data from the animal clades in contention and their closest relatives, then by applying innovative and state-of-the-art phylogenomics, comparative genomics and molecular dating techniques, and thirdly through harnessing the power of hidden diversity in the environment through metagenomics. We will use our novel high-quality data to infer the animal tree of life, and importantly, to reconstruct the gene content and metabolism of their last common ancestor. Thanks to the use of complete sets of proteins, we will be able to address this question, for the first time, from a higher hierarchical level, rather than merely looking at the differences between gene histories. We can use our inference of these interacting metabolic networks, which are more conserved across deep time, to understand the evolution of the group and reconstruct the metabolism of the last common ancestor of animals.