Why is there anything but cancer? If we are nothing but a collection of individual cells, and if individual cells are perfectly competent at fulfilling their own morphological, behavioral, and physiological needs, then how is it that multicellular organisms—and healthy, functioning ones at that—even exist?

Michael Levin explores these questions and more, including:

Is cancer a form of swarm intelligence, or the breakdown of it? Are cancer cells particularly “selfish,” as many scientists believe, or are they just as selfish as any other biological system? How does the regeneration of amphibian legs stop at just the right point, and what does this tell us about collective cell decision-making? In the absence of broken hardware (e.g. mutated proteins), how and why does cancer begin? Is there a common language amongst many different cell types in the body? Michael Levin is a Distinguished Professor, Principal Investigator of the Levin Lab, and Director of the Allen Discovery Center at Tufts University, where he investigates how biological and non-biological systems underlie decision-making processes. How does memory storage, decision-making capabilities, and coherent, system-level behaviors emerge from biological and artificial artifacts?

According to Michael Levin, the answer lies in the cooperative behavior of individual cells—a type of swarm intelligence. Just like the individual ants in an ant colony behave collectively to reach a larger goal, so too do individual cells in the “colony” of an organism, like a human being. In order to repair and build a human body, individual cells must be connected to and behave in accordance with the collective, rather than operate at the individual level.

But it goes so much deeper than that. Consider, for instance, the regeneration of a salamander limb. Following amputation, a normal limb indistinguishable from the original is developed over the course of a few weeks. How does this regeneration stop precisely where it should? Why doesn’t the salamander end up with a limb that never stops getting longer?

Levin says that the stopping point of regeneration requires that the cellular collective compare the current anatomy of the organism to the layout of a correct salamander forelimb, and stop when the error rate is zero (or close to). In other words, the cellular collective can ascertain whether and when the anatomy is correct, and cease growth when appropriate.

Mechanisms of cellular communication are many, and it is this communication—this connectedness between individual cells—that allows for a cellular collective to have goal-directedness, which in turn, leads to salamanders with perfectly regenerated limbs (as just one of many examples).

Levin and his group are
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https://www.youtube.com/watch?v=8sKdzFmc5M4