Evolutionary medicine

Published on April 30, 2023   48 min

Other Talks in the Series: Introduction to Evolutionary Biology

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Hello, this is Steve Stearns. I was a professor of ecology and evolutionary biology at Yale. I am now retired. Welcome to this talk on evolutionary medicine.
I'd like to begin by discussing what evolution contributes to medical science. I think its most important contribution is its integration of insights across levels. Having a framework like that makes it easier for physicians to remember and integrate the vast amount of information that they have to learn. Evolutionary insights also stimulate new questions for research and suggest new therapies in the clinic. We'll be following up on both of those points during this talk.
The issues that evolutionary insights impact include those listed here on the slide. I would like to make a few remarks about some of them. Mismatch means we're better adapted to past environments than to the new conditions that were created by civilization. These new conditions impose ongoing natural selection. Insight into aging is basically that the vulnerabilities in the design of our bodies that lead to aging are there because there are trade-offs between reproduction and survival early in life and survival later in life. Aging itself is not an adaptation. Insight into pathogen evolution is, I suppose, the fact that we're very lucky to be here at all because we are locked in a co-evolutionary arms race with our pathogens. They have the advantages of short generation times, huge populations, and higher mutation rates. We'll be looking at the COVID pandemic as a dramatic case study in rapid pathogen evolution in real-time. Our microbiota had been with us since the origin of life, and its many roles are being increasingly appreciated, but we're not going to be discussing them in this talk, that would take too much time. There are a number of interesting insights into cancer. Every individual cancer is a novel evolutionary process and our vulnerability to cancer is built into ancient features of our organismal design. Cancer appears to be inevitable. Insight into reproductive medicine stems from the fact that reproduction is so central to evolutionary success. We will be exploring the connections between mammalian reproduction and cancer metastatis later in this talk. In terms of applications, evolutionary medicine has already produced insights that are shaping both clinical practice and public health policies. We're going to look at one of them in some detail - phage therapy.