Seminar series

How precisely can we date the timeline of early human evolution? The Turkana Basin in northwestern Kenya is one of the most important paleoanthropological regions, preserving hominin fossils and archaeological evidence within sedimentary sequences interbedded with volcanic ash layers (tuffs). These tuffs act as the key to establishing a temporal framework for understanding when key evolutionary and behavioral changes occurred.

We combine high-resolution ⁴⁰Ar/³⁹Ar geochronology combined with grain-specific major and trace element geochemistry to generate distinct temporal and geochemical fingerprints for tuffs within the Nachukui Formation, west Turkana. By refining age estimates and enhancing tuff identification, this study aids intra- and inter- basin correlation, improves the chronology of key paleoanthropological sites, provides insights into silicic volcanic processes, and explores the possible links amongst recurrent volcanism, paleoenvironmental changes, and hominin evolution.

Title: Caves and their stalagmites: linking climate to groundwater recharge

Abstract: Groundwater is a natural resource supporting industry, agriculture and water supply worldwide. It is especially important in drier, water-limited parts of the world, where it can provide a resilient water source in times of drought. Despite this economic importance, we do not know how the replenishment of groundwater (technically known as groundwater recharge) relates to climate phenomena such as El Niño and La Niña. This is increasingly important as we adapt to climate change and associated climate extremes, such as the recent rare occurrence of three consecutive La Niña years. This knowledge gap can be filled by using caves, uniquely situated between the land surface and the groundwater, as observatories of groundwater recharge in the past, present and future. This lecture will explain how we can generate new knowledge by combining the analysis of cave stalagmites to understand when recharge occurred in the past; underground hydrological monitoring today to work out how much rainfall is needed and the associated weather and climate patterns; and climate and hydrological modelling to identify when this replenishment will occur in the future. Using these approaches, we can identify the climate conditions most likely to lead to the rainfall recharge of groundwater, and how this recharge of groundwater will change with future climate change. This new knowledge can be used to help identify where groundwater can be sustainably used for water supply and industrial use in the future and to mitigate the impacts of longer and more intense droughts that are predicted with climate change.

Name: Dr Thomas Schmidt
University: The University of Sydney

As genomic data have become increasingly cheap to generate, they have seen a range of new uses for understanding pest populations. This talk will first detail how a big international dataset has been built to track recent evolution in mosquitoes, covering fundamental evolutionary processes such as repeated adaptation and long-distance dispersal as well as applied biosecurity questions such as inferring incursion origins and tracking insecticide resistance evolution. The second part of the talk will show how genomic data can be used to infer the natural histories of poorly understood and enigmatic pests such as the shot-hole borers that have recently invaded Australia. The talk will provide a synthesis of how evolutionary genomic pest studies can be shaped to answer applied and fundamental questions.

Title: Plant afterlife: stories from two decayers

Abstract: Wood is the largest above ground terrestrial biotic store of carbon. These stores can persist for centuries to millennia. Termites and fungi are the two major biotic decayers that break down wood, releasing carbon and nutrients back to the environment. This talk will explore how wood construction and environmental conditions shape the relative abilities of these two decayers to do their jobs, leading to consequences for ecosystem processes such as the rates and forms that carbon is cycled during the plant afterlife.

Title: Landscapes of infection: the role of the environment in shaping vector-borne disease transmission

Abstract: Despite the recent gains in reducing the overall global burden of parasites like malaria, vector-borne diseases still account for 17% of all infectious diseases and cause 700,000 deaths in humans annually. Further, climate and land use change are dramatically modifying the landscapes across which vector-borne pathogens are transmitted. Our research applies ecological and evolutionary theory to understand how environmental variation will shape the outcome of the host- pathogen interaction, and the transmission and control of vector-borne diseases now and in the future. I value cross-scale inference, with research questions that span multiple biological scales and mosquito-pathogen systems (Aedes – Zika (ZIKV), Dengue (DENV) viruses, Culex - West Nile virus (WNV), and Anopheles – rodent and human malaria. My research is trans-disciplinary and integrative, adopting theory from the fields of ecology, evolutionary biology, genetics, virology, parasitology, medical entomology, statistics, and immunology. Finally, we use a combination of laboratory experiments, descriptive and experimental studies in the field, and mathematical modeling to answer questions on how environmental variation affects three central areas: 1) the mosquito-pathogen interaction, 2) pathogen transmission dynamics, and 3) evaluating the efficacy of different intervention strategies to answer critical questions on the effects of climate and land use change on current and future vector-borne disease transmission and control.

Efforts to conserve and restore biodiversity increasingly aim to address demands for environmental justice, yet substantial theoretical and practical challenges remain. This talk examines how social-ecological approaches to biodiversity conservation and restoration engage with environmental justice, using it as a critical analytical lens. Drawing on empirical research and practice-based experiences from East and South Africa, alongside selected European examples, I explore how governance processes and implementation contexts may influence justice outcomes in conservation and restoration initiatives and research. The presentation highlights key tensions, constraints, and opportunities emerging in practice and invites discussion on the relevance of these insights in other regional contexts.

Title: How GREAT is the Great Barrier Reef today?
The good, the bad… and some ugly aspects of this iconic World Heritage Area

Abstract: Despite its international recognition, and being World Heritage listed, the global reputation of the Great Barrier Reef (GBR) has over the past 50 years experienced some amazing highs as well as several disturbing lows. This presentation will be in three parts, firstly, it will outline globally innovative aspects of marine management for which Australia should be rightly proud, resulting in the GBR being labelled ‘arguably the world’s best managed MPA’. I will then proceed to examine why the most recent official government assessment rates the outlook for the GBR as ‘very poor’, with the cumulative pressures from a wide range of increasing threats leading to the GBR being in the international spotlight and potentially listed as ‘In-danger’. Finally, a few alarming aspects of marine mismanagement in the GBR will also be discussed.