You Complete Me: A Symbiotic View of Life

You're never alone. As biologist Scott Gilbert, Ph.D. explains, you're just the largest neighbor in your holobiont community: you and the symbiotic organisms in, on, and around you.

A Weeknights at the Wagner online lecture, October 1, 2020.
As humans, we tend to think of ourselves as biological individuals, the product of the fertilized egg whose cells form a community that has an immune system to protect it from foreign cells and substances. However, biology of the 21st century shows that we are not merely individuals; we are biomes, collections of numerous integrated ecosystems. In this view, animals cannot be considered individuals by either anatomical or physiological criteria because diverse symbionts – organisms living in symbiosis - are present and integral to their physiological processes. Similarly, new studies show that animal development is incomplete without symbionts. Even the immune system is formed in dialogue with symbionts and functions as a mechanism for integrating microbes into the animal-cell community. Symbionts also constitute a second mode of genetic inheritance.

Dr. Scott Gilbert introduces the concept of the “holobiont” – a host organism plus its colonies of symbionts - and research that is fundamentally changing our understanding of biological individuality and evolution. Recognizing the “holobiont” as a critically important unit of anatomy, development, physiology, immunology, and evolution is opening up new investigative paths and conceptually challenging the ways that the biological sciences are characterizing living entities.

About Scott Gilbert, Ph.D.
Scott F. Gilbert is the Howard A. Schneiderman Professor of Biology, emeritus, at Swarthmore College, as well as a Finland Distinguished Professor, emeritus, at the University of Helsinki. He is also a member of the Wagner Free Institute of Science's Advisory Board. Trained as a developmental biologist and historian of science, Scott has taught embryology, developmental genetics, and history of biology for 35 years. His research has focused on how evolutionary novelty comes into existence through changes in gene expression and changes in symbiont acquisition. He is considered an expert on two critical questions in evolution and embryology: How the turtle gets its shell, and how the cow gets its specialized stomach. Having majored in both biology and religion, Scott has spoken in several Vatican conferences, and in 2016 he was honored to present a developmental biology lecture to His Holiness, the Dalai Lama. He currently has three textbooks in print: (1) Developmental Biology, (2) Ecological Developmental Biology, and (3) Fear, Wonder, and Science in the New Age of Reproductive Biotechnology.