How from a cloud of dust and gas did we arrive at a planet capable of supporting life? This is one of the most fundamental of questions, and engages everyone from school children to scientists. We now know much of the answer: We know that stars, such as our Sun, form by the collapse of interstellar clouds of dust and gas. We know that planets, such as Earth, are constructed in a disk around their host star known as the planetary nebula, formed by the rotation of the collapsing cloud of dust and gas. We know that 4.5 billion years ago in the solar nebula, surrounding the young Sun, all the objects in our Solar System were created through a process called accretion. And among all those bodies the only habitable world yet discovered on which life evolved is Earth. There is, however, much that we still do not know about how our Solar System formed. Why, for example, are all the planets so different? Why is Venus an inferno with a thick carbon dioxide atmosphere, Mars a frozen rock with a thin atmosphere, and Earth a haven for life? The answer lies in events that predated the assembly of these planets; it lies in the early history of the nebula and the events that occurred as fine-dust stuck together to form larger objects known as planetesimals; and in how those planetesimals changed through collisions, heating and the effects of water to become the building blocks of planets. Our research will follow the evolution of planetary materials from the origins of the first dust grains in the protoplanetary disk, through the assembly of planetesimals within the solar nebula to the modification of these objects as and after they became planets. Evidence preserved in meteorites provides a record of our Solar System's evolution. Meteorites, together with cosmic dust particles, retain the fine-dust particles from the solar nebula. These dust grains are smaller than a millionth of a metre but modern microanalysis can expose their minerals and compositions. We will study the fine-grained components of meteorites and cosmic dust to investigate how fine-dust began accumulating in the solar nebula; how heating by an early hot nebula and repeated short heating events from collisions affected aggregates of dust grains; and whether magnetic fields helped control the distribution of dust in the solar nebula. We will also use numerical models to simulate how the first, fluffy aggregates of dust were compacted to become rock. As well as the rocky and metallic materials that make up the planets, our research will examine the source of Earth's water and the fate of organic materials that were crucial to the origins of life. By analysing the isotopes of the volatile elements Zn, Cd and Te in meteorites and samples of Earth, Moon and Mars we will establish the source and timing of water and other volatiles delivered to the planets in the inner Solar System. In addition, through newly developed methods we can trace the history of organic matter in meteorites from their formation in interstellar space, through the solar nebula and into planetesimals. Reading the highly sensitive record in organic matter will reveal how cosmic chemistry furnished the Solar System with the raw materials for life. Once the planets finally formed, their materials continued to change by surface processes such as impacts and the flow of water. Our research will examine how impacts of asteroids and comets shaped planetary crusts and whether this bombardment endangered or aided the emergence of life. We will also study the planet Mars, which provides a second example of a planetary body on which life could have appeared. Imagery of ancient lakes on Mars will reveal a crucial period in the planet's history, when global climate change transformed the planet into an arid wasteland, to evaluate the opportunity for organisms to adapt and survive and identify targets for future rover and sample return missions.

Anthropogenic disturbance and land-use change in the tropics is leading to irrevocable changes in biodiversity and substantial shifts in ecosystem biogeochemistry. Yet, we still have a poor understanding of how human-driven changes in biodiversity feed back to alter biogeochemical processes. This knowledge gap substantially restricts our ability to model and predict the response of tropical ecosystems to current and future environmental change. There are a number of critical challenges to our understanding of how changes in biodiversity may alter ecosystem processes in the tropics; namely: (i) how the high taxonomic diversity of the tropics is linked to ecosystem functioning, (ii) how changes in the interactions among trophic levels and taxonomic groups following disturbance impacts upon functional diversity and biogeochemistry, and (iii) how plot-level measurements can be used to scale to whole landscapes. We have formed a consortium to address these critical challenges to launch a large-scale, replicated, and fully integrated study that brings together a multi-disciplinary team with the skills and expertise to study the necessary taxonomic and trophic groups, different biogeochemical processes, and the complex interactions amongst them. To understand and quantify the effects of land-use change on the activity of focal biodiversity groups and how this impacts biogeochemistry, we will: (i) analyse pre-existing data on distributions of focal biodiversity groups; (ii) sample the landscape-scale treatments at the Stability of Altered Forest Ecosystems (SAFE) Project site (treatments include forest degradation, fragmentation, oil palm conversion) and key auxiliary sites (Maliau Basin - old growth on infertile soils, Lambir Hills - old growth on fertile soils, Sabah Biodiversity Experiment - rehabilitated forest, INFAPRO-FACE - rehabilitated forest); and (iii) implement new experiments that manipulate key components of biodiversity and pathways of belowground carbon flux. The manipulations will focus on trees and lianas, mycorrhizal fungi, termites and ants, because these organisms are the likely agents of change for biogeochemical cycling in human-modified tropical forests. We will use a combination of cutting-edge techniques to test how these target groups of organisms interact each other to affect biogeochemical cycling. We will additionally collate and analyse archived data on other taxa, including vertebrates of conservation concern. The key unifying concept is the recognition that so-called 'functional traits' play a key role in linking taxonomic diversity to ecosystem function. We will focus on identifying key functional traits associated with plants, and how they vary in abundance along the disturbance gradient at SAFE. In particular, we propose that leaf functional traits (e.g. physical and chemical recalcitrance, nitrogen content, etc.) play a pivotal role in determining key ecosystem processes and also strongly influence atmospheric composition. Critically, cutting-edge airborne remote sensing techniques suggest it is possible to map leaf functional traits, chemistry and physiology at landscape-scales, and so we will use these novel airborne methods to quantify landscape-scale patterns of forest degradation, canopy structure, biogeochemical cycling and tree distributions. Process-based mathematical models will then be linked to the remote sensing imagery and ground-based measurements of functional diversity and biogeochemical cycling to upscale our findings over disturbance gradients.