Periodic Reporting for period 3 - INNOVATION (Innovation and opportunity in the evolution of life)
Periodo di rendicontazione: 2021-10-01 al 2023-03-31
How does morphology evolve, and how did some groups such as birds become so successful, when their closest relatives, crocodiles, did not?
The first aim of this project is to produce a complete phylogenetic tree of tetrapods (30,000 living species; 10,000 extinct species) and use this to explore a core question in macro- evolution: how has the balance between innovation and opportunity affected the evolution of life?
The second aim is to use the distribution of characters across the tree to construct a model for morphological evolution.
We plan to produce three outputs:
1. the complete evolutionary tree of tetrapods;
2. a table of morphological characters across all tetrapod groups; and
3. a large number of documented case studies of macroevolution among tetrapods (e.g. amphibians, early reptiles, dinosaurs, birds, mammals).
In sum, these will provide the largest-ever geologically dated morphological evolutionary tree and character set, so enabling a thorough exploration of key evolutionary drivers and models across a single important clade.
The first aim of this project is to produce a complete phylogenetic tree of tetrapods (30,000 living species; 10,000 extinct species) and use this to explore a core question in macro- evolution: how has the balance between innovation and opportunity affected the evolution of life?
The second aim is to use the distribution of characters across the tree to construct a model for morphological evolution.
We plan to produce three outputs:
1. the complete evolutionary tree of tetrapods;
2. a table of morphological characters across all tetrapod groups; and
3. a large number of documented case studies of macroevolution among tetrapods (e.g. amphibians, early reptiles, dinosaurs, birds, mammals).
In sum, these will provide the largest-ever geologically dated morphological evolutionary tree and character set, so enabling a thorough exploration of key evolutionary drivers and models across a single important clade.
In 2020-2021, we progressed with all actions of the proposal. The two major aims are ‘balance of innovation and external events in shaping modern biodiversity’ and ‘testing models of morphological evolution’. Most progress has been made on the first aim, as planned, with initial progress in Aim 2 particularly by PDRAs Keating and Stubbs. Under Aim 1, we have completed work on comparing diversity and disparity signals in key clades (Objective 1A), including archosaurs and synapsids, and we have work underway, submitted, and recently published on crocodylomorphs, lepidosaurs and birds. In 2020, we published one study. On evolution of flight efficiency in pterosaurs, in Nature. We are also working hard on the timing of origin of modern species-rich clades (Objective 1B), with a study of lepidosaurs just published in Royal Society Open Science, and another about to be submitted to PNAS. We have several studies in progress in which we compare biodiversity, morphospace and function space (Objective 1C), and these concern lepidosaurs, crocodiles, birds, and Mesozoic marine reptiles, and we have recent publications in PRSB, Current Biology, and Nature Communications. We are also concentrating on the role of mass extinctions in reshaping diversity, disparity and ecospace data (Objective 1D), and the focus at present is on two events, the end-Permian mass extinction and the Carnian Pluvial Event (252, 232 Ma) – several papers have been published and others are in review, most notably one just accepted for publication at Nature Communications. In 2020, we published a definitive review of the Carnian Pluvial Event in Science Advances. We are beginning work on the subject of triggers of clade expansion (Objective 1E), with a focus initially on birds, to see how the assembly of their key adaptations drove their two-phase diversification (Cretaceous, Palaeogene) when compared to external environmental drivers; the paper is nearly ready to submit. Finally, we have a number of studies underway comparing post-extinction and ‘normal’ times (Objective 1F), initially focused on Triassic tetrapods, but with plans to consider other events and clades. Our work on mapping disparity of all life (Objective 2A) and the model for morphological evolution (Objective 2B) are now being set out for a start; it took some time to work out the frames of these ambitious projects, and to develop the work pipeline. In this area, we have published an initial study on ancestral state reconstruction methods in Systematic Biology (Objective 2B), and have further large-scale simulation studies underway at present.
The project is by its nature interdisciplinary. We work across the phylogenomics-palaeobiology line and engage with the research communities on both sides. It’s a fruitful time to be doing work of our kind because software developed for the exclusive use of the molecular biology community (e.g. MrBayes, phytools) is adapting to incorporate fossil data, and we are part of the vanguard of palaeontologists seeking to engage with the molecular community in setting ages for key nodes in trees in reasonable ways. Our Bayesian simulations of fossil data, through the fossilized birth-death (FBD) routines in MrBayes are an obvious bridge between the two communities.
Our work is at the heart of large-scale questions in evolutionary biology, many of which track back to Darwin (e.g. why are some groups such as birds so species-rich and others such as crocodiles are not? How do form and function relate to each other? How much of evolution is driven by the external environment, and how much by innovation?). The knowledge transfer comes through publication in the scientific literature, and we make strenuous efforts to pitch our papers at top journals and to spend considerable time promoting our work to a wide range of communities, including the general public, children, and decision-makers. This is reflected in the amazing responses we receive in social media and news reporting venues, reflected in generally impressive Altmetric data (https://ercinnovation.blogs.bristol.ac.uk/publications/). Further knowledge transfer will occur shortly when we publish new computational packages in the R environment and others, and which will prove useful to the large molecular-evolutionary biology research community.
Our work is at the heart of large-scale questions in evolutionary biology, many of which track back to Darwin (e.g. why are some groups such as birds so species-rich and others such as crocodiles are not? How do form and function relate to each other? How much of evolution is driven by the external environment, and how much by innovation?). The knowledge transfer comes through publication in the scientific literature, and we make strenuous efforts to pitch our papers at top journals and to spend considerable time promoting our work to a wide range of communities, including the general public, children, and decision-makers. This is reflected in the amazing responses we receive in social media and news reporting venues, reflected in generally impressive Altmetric data (https://ercinnovation.blogs.bristol.ac.uk/publications/). Further knowledge transfer will occur shortly when we publish new computational packages in the R environment and others, and which will prove useful to the large molecular-evolutionary biology research community.