Time Travel without a Time Machine: Modern Approaches to Evolutionary Biology

Evolution over billions of years has generated a breathtaking diversity of life on Earth, with each of these organisms possessing their own spectacular adaptations to the world around them. For centuries, trying to understand these patterns of diversity and adaptation meant examining living wild populations or the dead fossil record and trying to infer the evolutionary processes that gave rise to them. But now, we have a way of watching and controlling evolution right before our very eyes - laboratory experimental evolution with rapidly-evolving microbes. In this talk, I will highlight the history of experimental evolution, including our most famous experiment which has been running for over 35 years! We’ll explore the weird and wonderful world of microorganisms, which cooperate and cheat, attack and defend, communicate and deceive. We’ll then see how several evolution experiments have helped us: ‘replay the tape of life’ to understand how similar or different life could have looked if we started over; explore major transitions in life’s history including how we became multicellular and why we have sex; and uncover how we went from a single common ancestor to the dazzling array of lifeforms we see today. Finally, we’ll see how experimental evolution is helping us overcome challenges in public health and disease, including antibiotic resistance.

Genes are the blueprint for all life forms, driving everything from biochemistry to development and physiology. One of the most striking pieces of evidence for the shared ancestry of all life is the discovery that most human genes are found across the tree of life: 99% of our genes have counterparts in mice, 70% in fruit flies, 20% in plants, and even about 10% in bacteria. But where do the genes that make each organism unique come from, and how do they shape the diversity of life? In this talk, I will first provide an overview of how scientists use genome sequences to unravel the origins of young genes in evolution, which are found in particular groups of organisms but not in others. We’ll explore examples of how newly-evolved genes contribute to unique abilities and forms, from fish surviving in freezing Antarctic waters to the development of human intelligence. Finally, I will share some surprising results from my own PhD research, where I discovered that some animals can acquire new genes from other species in their environment—leading to a gnat capable of producing its own antibiotics, vitamins, and even anti-aging molecules. These discoveries not only shed light on the process of gene evolution, but also have far-reaching implications, from pest control strategies to understanding the origins of human disease.