Constraining the origins of the Metazoa: Insights from ichnology, palaeoecology and taphonomy

Life on Earth has experienced a remarkable history, in which it has endured climatic catastrophes, developed incredible biological innovations, and survived cycles of extinction and radiation as organisms have continually adapted to their changing environment. One of the most dramatic intervals of Earth history is the late Neoproterozoic Era some 700-541 million years ago (Ma), which witnessed amongst other things the biological recovery from the great Snowball Earth global glaciations, and the evolution and radiation of the first animals.

Characterizing and explaining the evolution of animals is currently one of the most topical areas in palaeontology. It not only excites philosophical interest, but also provides a wealth of scientific information that can advance our understanding of evolutionary processes and the interactions between life and the planet at times of major environmental change. Traditionally, scientists considered animals to have evolved suddenly and rapidly at the base of the Cambrian period, 541 Ma. That view was challenged in the 1940s and 1950s by the discoveries of complex fossilized impressions in rocks of Precambrian age - a suite of large, multi-cellular organisms that have become known as the Ediacaran biota. Their discovery prompted a paradigm shift from a rapid "Cambrian Explosion" model of animal evolution at the base of the Cambrian, to an "Ediacaran-to-Cambrian transition" whereby animal evolution extended over tens of millions of years.

Ediacaran (635-541 Ma) fossils are currently known from over 50 localities worldwide and include more than 100 different species, but they remain some of the most enigmatic and controversial fossils in the geological record. Since they are preserved as impressions of soft-bodied organisms rather than as shells, bones, or teeth, and the shapes and structures of the fossils differ from those of any living organisms, there has been much disagreement amongst scientists about what the fossils might have originally been. An emerging view, however, is that the Ediacaran biota may include the remains of some of the first true animals.

My research explores the initial evolution of animals, examining the causes for their emergence, and the consequences of their appearance for other organisms in marine habitats. In this project I aim to resolve the relationships between Ediacaran organisms and modern animals alive today, and investigate the ways in which Ediacaran fossils are preserved around the world, in order to improve our understanding of the timing and progression of animal evolution. By combining detailed study of Ediacaran fossils, sediments, and environments with experimental work to recreate the pathways through which organisms were fossilized 580 million years ago, I hope to constrain models for fossil preservation, and provide new insights into the tissues the organisms were originally composed of. I will also investigate the fossil record of animal movement in the Ediacaran period, since in recent years this has become a key piece of evidence for the presence of animals. Results I obtain will be fed into molecular studies, which will allow better prediction of how and when the major animal groups diverged and evolved at this critical point in Earth history.

Taken together, the proposed project will rigorously address the questions of when and why animals evolved by improving our understanding of Ediacaran organisms and environments. It will reveal new information about Ediacaran marine ecosystems, and, most importantly, will provide us with a clearer picture of the steps involved in early animal evolution.

The proposed research has the potential to provide social or economic impacts for five primary user groups:

Policy makers: Many of my study sites are either located within protected areas (e.g. Flinders Ranges National Park in Australia), or are currently working towards obtaining additional protective legislation (e.g. SSSI status for Charnwood sites in the U.K., and bids to make the Catalina Dome in Newfoundland a UNESCO Geopark, and Mistaken Point Ecological Reserve a World Heritage Site). The strength of these bids, and the case for continued protection and funding, is dependent in part on the scientific significance and importance of the fossil resources the sites contain. Groups such as Natural England and the National Trust (U.K.), Parks and Natural Areas Division (Newfoundland), and the Coaker Foundation (Newfoundland) will be particularly interested in the findings of this project.

General public: Many members of the general public have an interest in animal evolution, since as well as being of direct relevance to our own origins, it plays an important role in many philosophical, evolutionary, and theological discussions. People are keen to know how we as humans evolved.

Local communities living near to fossil sites: Exceptional fossil sites have long been considered as potential sources of revenue for their neighbouring communities. Historically, fossils were sold to museums and collectors, but more recently they have become tourist attractions and sources of inspiration for artwork. However, local communities need to have accurate information about the nature and significance of their sites in order to fully realise economic and social benefits.

Schools: Teaching of evolution is a core part of the curriculum in the U.K.

Museums: Local museums in Bristol, and museums in the countries of the study areas, have exhibits and collections of Ediacaran material for research and educational purposes.


How will these groups benefit?

Policy makers: My research may produce scientific advances or discoveries that are of national or international importance, and these would increase the prestige and significance of their host sites, permitting policy makers to recognize and utilize their full scientific potential, and to provide adequate site protection. My image dataset can also be used by policy makers to monitor site erosion and the condition of fossils, allowing better resource management.

General public: Benefits will be in the form of an increased understanding of animal evolution, and will be realized via appropriate distribution of knowledge obtained by this project through a variety of outreach media.

Local communities: My work will directly reveal the scientific importance of the fossils at each site, providing communities with the information they need to assess how best to promote their fossil resources to local funding agencies and tourists. By ensuring that communities receive accurate information, any tourism endeavors they develop are far more likely to be successful. Through the development of resources for sale to tourists, and in some cases of guided tours to the fossil sites, the local economy can be boosted (since tourists bring with them revenue for food, accommodation, and transport), and a sense of local pride in the community is often developed.

Schools: My research will provide insights into some of the most critical and fundamentally important questions in evolutionary history, and could be incorporated into teaching of components of biology or geology at secondary school level to ensure students receive the most up-to-date information for their education.

Museums: By studying existing collections, and potentially adding new material to some of them, my work will boost the research profile of host institutions, increase their value as scientific resources, and provide the knowledge necessary for gallery managers to create informative, educational displays.