Professor of Botany & Fellow of the Wisconsin Institute for Discovery
College of Letters & Science l Department of Botany
Hometown: London, England
- Understanding the origin of life demands that we reconceptualize life as an immortal, planet-level, ecosystem composed of numerous, ecologically-interacting “chemical tornadoes” (autocatalytic cycles). This new way of understanding life supports new laboratory research at UW, which is hinting that the origin of new life may not be rare and improbable as we once thought.
- Charles Darwin is most famous for proposing evolution by natural selection, but he is equally important for recognizing that living organisms are all connected as branches of the “Great Tree of Life.” Over the last two decades scientists have come to appreciate that understanding the tree, “tree thinking,” is essential to understand the natural world and humanity’s place in it.
Professor Baum will share some of his experiences as a graduate student studying the exotic pollination biology of baobab trees in Madagascar and Australia and then try and explain how this foundation serves him even today as he conducts research in such modern fields as molecular phylogenetic, genomics, and evolutionary developmental genetics. As a field scientist he learned theessence of scientific inquiry – thoughtful questioning and careful and self-critical observation and experimentation. Furthermore, the field setting provided him abundant opportunities to develop his own theoretical perspectives that provided the basis of his scientific accomplishments. This is not to say that field research is the only route to success in laboratory science. But what it does show is that science benefits when scientists come from different backgrounds and have diverse career paths.
The core of the origin of life problem is to explain the emergence of systems that can grow and evolve adaptively. This poses the ultimate chicken-and-egg problem: Adaptive evolution is needed to explain complexity, but evolving adaptively requires reproduction which, in all life that we know of, is very complicated. A resolution to this paradox is suggested by recent advances in evolutionary theory, which point to the surfaces of minerals as a location where a kind of selection, which I call neighborhood selection, can occur and could eventually result in the origin of cells. Excitingly, this insight suggests that it might be possible to create new evolving chemical systems, “life” in a very generic sense, in the laboratory. I will describe these experiments and any progress we have made at the time.
Arguably the most important evolutionary event in the history of life on earth was the origin of complex, eukaryotic cells, such as found in animals, plants, and fungi. These cells have various internal membrane-bound structures, including the nucleus, which houses the DNA, and mitochondria, which generate most of the cell’s energy supply. Biologists have long puzzled over the origin of these cellular features. Many theories have been proposed, all of which assume that an ancestral, simple cell internalized membranes and evolved the nucleus and other structures inside the original cell body. As an undergraduate student I dreamt up an alternative theory which, literally, turns the existing model “inside out.” Instead of creating a nucleus within the ancestral cell, I think that an ancestral cell, corresponding to the nucleus, created an outer compartment in the course of interacting with extracellular bacteria. I recently began working with a cell biologist on this theory and find that it fits the available information surprisingly well. This well illustrates the principle that sometimes naive individuals can have valuable scientific insights.
- Baobab trees, which are native to Africa, Madagascar, and Australia are among the world’s most remarkable plants. As well as being perhaps the most long-lived and massive trees, they have diverse interactions with animals and humans throughout their range, including a complex pollination system. The speaker will share his insight from more than 30 years of research into these botanical marvels.