Palaeobiology

Paleobiology is an interdisciplinary field of research that studies the Earth and how life on Earth has developed and adapted to changes in the environment and climate over long periods of time. We also investigate the biological and geological processes that have influenced and shaped the history of life on our planet. Paleobiologists seek answers to questions such as; How have different species evolved and disappeared over time? What factors have influenced these processes? How have changes in climate affected life on Earth and its evolutionary patterns?

Description

As far as we know, our Earth is the only planet in the universe where there is life. Humans represent only a fraction of all forms of life that have existed on our planet. At the Department of Earth Sciences, we strive to understand how life has evolved over millions of years and how it has adapted to constant changes in the environment and climate. We do this by combining traditional studies of fossils with modern biological methods. Of particular interest is the development of animals in connection with major biological events, especially what happened during the so-called Cambrian explosion – a short period more than 500 million years ago when we see a rapid increase in, among other things, shell-bearing animals. But it's not just the Cambrian explosion that attracts interest. The development of more modern animal groups in the middle of the Cretaceous period, as well as the major extinction event 65 million years ago when, among other things, dinosaurs became extinct, provides additional pieces to the puzzle of life's history and is part of our own development.

Microorganisms are found everywhere, from deep seas to high mountain peaks and even inside mountains themselves. Humans are in various ways completely dependent on these single-celled organisms, and they regulate much of our own existence, for example, by producing much of the oxygen we breathe or by breaking down and recycling organic material. At the Department of Earth Sciences, we try, among other things, to understand where these important organisms originated and how they have evolved in relation to the global climate. Our studies span several billion years of development, but particular emphasis is placed on the last 600 million years of evolution – from a time when virtually the entire Earth was covered in ice to the effects of more recent climate fluctuations.

Our Research

Early evolution of animals

Most of our understanding of Paleozoic animal life comes from preserved remains of hard parts, that is, shells and other mineralized parts of animals. By studying fossil remains from all over the world the focus is on investigating and reconstructing the relationships within and between important animal phyla, above all arthropods and brachiopods.

Shell-bearing organisms represent only a small part of the total diversity and therefore we also study non-mineralized remains in the form of organic small carbonaceous microfossils (and acritarchs). These types of microfossils preserve unique soft parts of animals, which are otherwise usually completely missing as fossils. With the help of these we can fill in some of the gaps in the early animal development.

Genetic and molecular evolution of development

Here we focus on the investigation and comparison of embryonic gene expression patterns, i.e. the place and time when genes that steer development are active. We mainly work on the so-called panarthropods, represented by the well-known arthropods (e.g. flies, butterflies, shrimps, spiders, scorpions, centipedes and millipedes), but also the enigmatic tardigrades (water bears) and the onychophorans (velvet worms) but also priapulids, vermiform ecdysozoan critters that are known since the Cambrian era, and that may share key morphological features with the last common ancestor of Ecdysozoa as a whole.

Phytoplankton evolution

Marine phytoplankton, such as diatoms and coccolithophores, are small algae that play a crucial role in marine ecosystems and the global carbon cycle. These algae sequester large amounts of the greenhouse gas carbon dioxide, just like trees and plants on land. Under current climate change, there are many questions of both scientific and societal interest: How will marine algae adapt to a much warmer world? How fast (or slow) will these adaptations occur? Will current species go extinct?

We can learn a lot about modern algae through field-based studies and laboratory experiments, but to understand the long-term effects of climate change and the evolution of phytoplankton, we need to look back in time and study how marine plankton communities have evolved on geological timescales. Scientific deep-sea drilling provides us access to a unique archive of microfossils and paleoclimate data from earlier periods of Earth's evolution. Deep-sea sediments store information about what the climate was like in the distant past, for example when only the southern hemisphere was glaciated and sea surface temperatures exceeded 28.5°C in the North Atlantic. Our research aims at understanding the dynamic interactions between climate change and marine phytoplankton across both short and long timescales, and relating this knowledge to changes in the global carbon cycle.

Biogeochemistry

Biogeochemistry explores the spatial and temporal changes in the natural environment driven by biological, geological, chemical, and physical processes. Life on Earth depends on nutrients such as carbon, nitrogen, and trace elements, and their availability for life is determined by the natural processes that circulate them through the environment. Biogeochemistry and our research focus aims to understand these circulation patterns to comprehend how life originated, developed, and adapted to environmental changes over time. We also aim to understand the abiotic processes that circulate elements in the environment, such as weathering and depositional patterns, as well as tracers of sources and sinks of elements in nature. Biogeochemistry spans the entire globe and all timescales and is an important base for a fundamental understanding of elemental circulation on our planet.

PhD Studies

According to international evaluations, Uppsala University has some of the most comprehensive research in geosciences in Europe, and our doctoral students at Uppsala University are among the most satisfied with their doctoral education. We offer doctoral studies in eight research areas.