DEEP ETHOLOGY – DEVELOPMENT – disintegration and renewal at the cellular level
DEEP ETHOLOGY
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DEVELOPMENT
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Disintegration and Renewal
including an excerpt from Scientific American
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In ART & ORGANISM we considered DEVELOPMENT at multiple levels of organization and in the light of CHANGE as an existential phenomenon as well as biological and cosmic. In the light of change as “A maelstrom of perpetual disintegration and renewal”… what do you think of the problem of about The Ship of Theseus ? ((a traditional problem (discussed since 500 BC) in the metaphysics of identity: if an an object that has had all of its components replaced over time is it the same object? (even the youngest Star Trek fans consider the implications of the transporter) see complete note: development-disintegration-renewal-and-the-paradox-of-the-ship-of-Theseus. (from A&O notes on DEVELOPMENT)
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“In the human body, hundreds of billions of cells are estimated to die each day, and they are mostly disposed of by a process called efferocytosis. If efferocytosis fails, then damaging inflammation can ensue.” [MORE] see DEEP ETHOLOGY notes on Disintegration and Renewal
“The human body replaces its own cells regularly. Scientists at the Weizmann Institute of Science in Rehovot, Israel, have finally pinned down the speed and extent of this “turnover.” About a third of our body mass is fluid outside of our cells, such a plasma, plus solids, such as the calcium scaffolding of bones. The remaining two thirds is made up of roughly 30 trillion human cells. About 72 percent of those, by mass, are fat and muscle, which last an average of 12 to 50 years, respectively. But we have far more, tiny cells in our blood, which live only three to 120 days, and lining our gut, which typically live less than a week. Those two groups therefore make up the giant majority of the turnover. About 330 billion cells are replaced daily, equivalent to about 1 percent of all our cells. In 80 to 100 days, 30 trillion will have replenished—the equivalent of a new you.”
Credit: Jen Christiansen; Sources: “Revised Estimates for the Number of Human and Bacteria Cells in the Body,” by Ron Sender, Shai Fuchs and Ron Milo, in PLOS Biology, Vol. 14; August 2016 (total cell data), and “The Distribution of Cellular Turnover in the Human Body,” by Ron Sender and Ron Milo, in Nature Medicine, Vol. 27; January 2021 (cell turnover data)
This article was originally published with the title “A New You in 80 Days” in Scientific American 324, 4, 76 (April 2021)
