Plenary and Public Lectures
The Public Lecture will be given by:
Professor Sean Carroll
"Remarkable Creatures: Epic Adventures in the Search for the Origins of Species"
The search for the origins of species, both in general and of specific kinds of creatures, has entailed a series of truly epic adventures over the past 200 years. Award-winning author and researcher Sean Carroll will chronicle the exploits of a group of explorers who walked where no one had walked, saw what no one had seen, and thought what no one else had thought. Their achievements sparked a revolution that changed, profoundly and forever, our perception of the living world and our place within it.
This lecture will take place during the evening of Wednesday June 30th in the Ondaatje Lecture Theatre of the Royal Geographical Society. Admission is free, but by e-ticket only (click to go to e-ticket order page). NOTE - this system is for members of the public only - IPC3 delegates who signed up for this lecture when registering do not need to sign up again.
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| The Ondaatje Lecture Theatre, Royal Geographical Society |
The Plenary Symposium will take place during the morning of June 29th in the Ondaatje Lecture Theatre of the Royal Geographical Society.
Biomolecular Palaeobotany - Molecular Records of Continental Vegetation in the Quaternary
Geoff Eglinton
University of Bristol, UK
Plant lipids carry the imprint of their biosynthetic origin in their strong, carbon-carbon bonded, molecular structures, which can be preserved over millions of years buried in ancient sediments. Leaf wax molecular signals are dispersed and persist on the global scale, surviving the numerous decay and diagenetic processes involved in plant death and consumption, wild fires, soil deposition and erosion, transport over thousands of kilometers in rivers and as aeolian dust, and finally deep-sea sedimentation and burial.
Although few types of biomarker lipids are species-specific, most can serve as indicators of the biosynthetic origin and physiological conditions involved in forming them, such as e.g. C3/C4 carbon fixation pathways and leaf water stress, and hence serve as palaeoclimate proxies. For example, the molecular abundance patterns and isotopic contents (delta13C, delta14C and deltaD) of fossil cuticular wax components, such as the homologous carbon number series of longer than C24, straight-chain alkanes, alkanols and alkanoic acids, can provide valuable records of palaeovegetational change and hence past environmental conditions. This compound-specific, isotopic approach avoids the averaging effects inherent in the classical isotopic and elemental analysis of bulk organic matter, provides complementary information to that afforded from pollen analyses, and has been successfully applied to Quaternary marine sediment cores globally. Examples include sites adjacent to the African continent, northern South America, the Arabian Peninsula, and the Indian sub-continent. Continuing improvements in analytical capabilities permit high-resolution multi-molecular proxy reconstructions, and extend the approach to a broader range of paleoclimate archives, including soils, lake sediments, loess-palaeosol deposits and glacial ice.
The Fossil Record of Microevolution
Gene Hunt
Smithsonian Institution, Washington DC, USA
Since Darwin, scientists have used patterns of phenotypic evolution in fossil lineages to shed light on evolutionary processes. In the first part of this talk, I will review some of these attempts, starting with Darwin's expectation of geologically gradual change, ranging through the Punctuated Equilibrium debates of the 1970s and 1980s, and finishing with more recent efforts that use modern statistical methods to determine the relative frequencies of gradual change, stasis, and other evolutionary patterns. I will argue that the empirical fossil record is mostly consistent with the tenets of Punctuated Equilibrium: phenotypic traits seldom trend gradually over geological time, and instead show meandering or fluctuating trajectories. The second part of this talk will discuss the more difficult, and largely unrealized, goal of relating paleontological patterns of stasis and change to microevolutionary processes such as natural selection and drift.
Evolutionary Regulation of Biodiversity in the Oceans
Wolfgang Kiessling
Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity at the Humboldt University Berlin, Berlin, Germany
The last decade saw many exciting developments in deep-time biodiversity studies. These advances have been made possible by the Paleobiology Database. We now know that the early view of unbridled diversity rise in the oceans of the last 100 million years is probably incorrect. The “Pull of the Recent” and sampling biases have distorted the outcome of earlier compilations of taxonomic ranges.
We also have a much better idea on the diversity dynamics that underlie the large scale patterns. First, diversity appears to be regulated at global scales: Declines of global diversity lead to subsequent declines in extinction rates and increases in extinctions are followed by increases in originations. Second, diversification was not governed by extinction in the Palaeozoic but by origination in Mesozoic and Cenozoic. The discovery that marine level-bottom community structure has changed substantially at the Permian-Triassic boundary, offers an elegant explanation for this observation. The ecologically complex communities that dominated Mesozoic and Cenozoic oceans created opportunities for speciation, whereas the simple Palaeozoic communities required extinction for new species to become established. Third, both origination and extinction rates vary systematically among habitats and over time. Rates are significantly larger in tropical, shallow water, calcium carbonate and reef habitats than in extra-tropical, deep water, terrigenous clastic and non-reef habitats. Reefs appear to be especially important in regulating marine biodiversity. The evolutionary cradle effect of reefs was higher in the Palaeozoic than later on, probably because community structure in reefs was always complex, whereas level-bottom communities gained complexity after the Palaeozoic.
These examples demonstrate once again how much the fossil record can contribute to understanding macroevolutionary dynamics and how much insight can be gained by community-wide efforts in palaeontology. We are getting close to a holistic and reliable picture on biodiversity dynamics in the oceans. What is yet needed is a rigorous theoretical framework for these patterns.
A Molecular Perspective on Human Origins
Svante Pääbo
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Extraction and sequencing of DNA from extinct hominins allow their relationships to present-day humans as well as to each other to be determined with accuracy. I will illustrate this by our work on Neandertals, who became extinct around 30,000 years ago, as well as a hominin bone fragment recently discovered in Denisova Cave in Southern Siberia. I will also describe our analysis of almost 3.7 billion bases from the Neandertal genome that we determined together with colleagues in Croatia, Spain, Russia, Germany and the US. This allows over 60% of all nucleotide sequences in the genome to be studied. Using these data we can now for the first time determine which substitutions occurred on the human evolutionary lineage and which parts of the human genome that was affected by positive selection after fully modern humans diverged from the Neandertal lineage.
From Rock to Reality? Multiple Approaches to Functional Analysis in Fossils
Emily Rayfield
University of Bristol, UK
Over the last decade, a suite of computer-based and engineering tools has enabled palaeontologists to conduct sophisticated morphofunctional analyses of fossils. These include imaging techniques such as synchrotron radiation x-ray microtomography (SRXTM), finite element analysis (FEA), quantitative microwear, and freely available morphometric software.
Validation studies are increasing our confidence in applying such in-silico methodologies, whilst advances in computing power and availability allow us to ask increasingly searching questions, from function of individual taxa to analysis of broad scale functional and evolutionary trends. Typically these studies employ one or two techniques in isolation. The aim of this talk is argue that there is now a critical mass in expertise and availability of such techniques. Therefore multi-dimensional functional analyses, combining several in-silico approaches, can now be used to gain the most holistic answer in functional analysis. I will present examples of work that have undertaken such a remit. Functional and ecological diversity and locomotor capabilities in stem mammals is considered, as is the function and evolution of the mammalian tooth. Other studies consider the morphofunctional evolution of the crocodilian and dinosaurian skull. All analyses use a combination of techniques ranging from SRXTM to traditional biomechanics to geometric morphometrics. Agreement of multiple strands of evidence should of course strengthen our confidence in functional interpretation. Furthermore the work is grounded in validation studies in birds and mammals, demonstrating that rocks to reality is not a one-way process, and information gleaned from living taxa is crucial to our understanding of their extinct forebears.