The new Op-Ed feature started last month with a piece by Joe Alcock, “Disabling the smoke detector in sepsis.” Our hope was that this feature would spark interest and contributions by more authors and so far we are off to a great start. Veterinary pathologist Edmund LeGrand has volunteered the following piece which examines, from an adaptationist viewpoint, the intriguing question as to why the human heart has such limited powers of post-infarction regeneration. We’d like to thank both Ed and Joe for their contributions and remind readers that we are open to contributions from anyone. We also want to encourage commentary on all of our Op-Ed pieces; please feel free to submit contributions and comments for approval to email@example.com.
Regeneration and the Heart of the Adaptationist Approach
Edmund K. LeGrand, DVM, PhD, DACVP
The ability to regrow an arm, a leg, or another large portion of the body that has been amputated is a more widespread trait than you might think. Invertebrates like sea stars and flatworms can replace most of their body parts after removal, but even some vertebrates have impressive regenerative abilities. Lizards regenerate their tails, newts can regrow limbs and repair parts of the eye, and zebrafish can regrow fins and repair other tissues like the heart. Mammals, however, are pretty limited in this realm of regrowth. Humans can regrow muscle and liver tissue, but regenerative repair of other organs, including the heart, is extremely limited. Why might this be? Two recent papers are notable in addressing the question (1, 2).
Cardiologist Barbara Natterson-Horowitz entered an operating room where her patient was already on the table. She’d had many patients in the past through the University of California at Los Angeles Medical Center, which trained her well for that moment. The foot sticking out from under the surgical towels, however, didn’t belong to a human. It belonged to a lion. How did being a human cardiologist prepare Barbara to work on lions? Humans and lions can’t be that similar, especially through the eyes of a doctor… right? Last Friday, Barbara kicked off the symposium “Implications of Anthropogeny for Medicine and Health” by highlighting the similarities of her patients across species. It was the first of many research talks that questioned the differences between humans and other animals and between populations of humans, as well as the similarities we have from shared origins. The University of California at San Diego (UCSD) and the Salk Institute’s Center for Academic Research and Training in Anthropogeny (CARTA) joined forces with the Arizona State University (ASU) Center for Evolution and Medicine to sponsor the symposium, which was free and open to the public. During talks that were peppered with descriptions of edible liquid gold, killer sugars, battles within wombs, and studies within tombs, visitors learned about the traits and diseases that make us human (and animal) products of our world.
Dr. Kevin Foster, from the University of Oxford, visited the Center for Evolution and Medicine at Arizona State University last week to talk about competition and sociability among a variety of bacteria, some of which call our guts home. Using humorous descriptions of psychedelic broccoli, tiger and lion fights, and breathing on hornet’s nests, he walked us through the complexity of sociality found in microbes, which ranges from competition among specific bacterial cells to between-species cooperation. Foster used to study social insects, but now he applies his expertise of social behavior (and kin selection) to microbes. While kin selection provides an evolutionary explanation for many complex social behaviors in eukaryotic organisms, it may also be a good model to use in understanding the behavior of genetically similar microbes and how such behavior may affect human health.