Living cells communicate (Introduction)

by dhw, Friday, October 05, 2012, 12:27 (4410 days ago) @ David Turell

DAVID: A new experimental way to study that communication. Life is very complex:-http://www.scientificamerican.com/article.cfm?id=cellular-calls-listening&WT.mc_id=...-Here is a quote from the article that fairly leaps off the page: -"Some signals instruct cells to grow and multiply; others "say" it is time to die. And some signals encourage stem cells—which can mature into a variety of cell types—to differentiate into specific lineages. Understanding cellular signaling is key for biologists hoping to discover how cells respond to one another and their environment."-On 13 December 2011, Page 10 of this forum, I opened a thread on the subject of The Intelligent Cell, and suggested that this might form the basic mechanism of evolution. It ties in perfectly with Lynn Margulis's emphasis on cooperation as a key factor in evolution, and it seems to me that this latest discovery, together with continuing advances in epigenetics, offers one more piece of evidence that there is an intelligent mechanism at work here which may explain not just adaptation but also, and all importantly, innovation. Perhaps it is stem cells that hold the key to the mystery, since they appear to be so versatile.-I don't see this as being contrary to Darwinism. The implication is that cells continually find new ways of combining in order either to survive environmental changes (by adaptation) or to exploit them (by innovation). What will have appeared to Darwin as random mutations were not random, but were a direct response to the environment. And those that worked survived (= Natural Selection). In other words, his description of the process was correct, but ... since he had no way of knowing the genetic mechanisms we are discovering today ... his speculation as to how it worked was wrong. I have never understood why he insisted that his theory depended on gradualism, or indeed why the title of his masterpiece states that species originate "by means of natural selection", but in the light of modern science 150 years later, his basic insight still stands up to scientific scrutiny: namely, that all forms of life evolved from earlier forms through diversification and suitability to existing environments. These new discoveries are on the way to explaining how.-In the context of design versus chance, his own agnostic open-mindedness also stands up to scientific scrutiny. Even he could never have dreamt how complex the mechanisms of heredity etc. would prove to be. The belief that these could somehow be attributed to chance clearly has no more basis in science than the belief that it was all designed by an eternal, universal, unobservable and inexplicable intelligence.