Cambrian Explosion: mutation rate (Introduction)

by dhw, Monday, September 23, 2013, 13:39 (4058 days ago) @ David Turell

DAVID: There is no way for cells independently to create a kidney. They have to be provided with an overall plan to follow. They are given this in my concept of pre-programming. -dhw: They are also given this in Margulis's concept of cooperation between "conscious entities". -DAVID: That is her interpretation, which I do not accept. Yes, consciousness pervades the universe, but it doesn't help cells innovate. There must be a prior overall plan.-I do not have a problem with your rejection of Margulis's interpretation. The problem is with your rejection of the concept as "poppycock", backed up only by your own subjective interpretations. 
 
DAVID: Bluntly cells do not exchange information, only chemical reactions.
BBella has challenged this: 
BBELLA: I thought this an interesting lecture (Lecture 6 in a series). -How do cells talk to each other and what do they say?-http://www.sysbio.org/resources/tutorials/2003series/biolecture5.pdf-Page 31 says this:-"Cells make different decisions depending on the input"
 
Seems as though cells do exchange information with each other. They may not speak in our language but through cell signals, etc., they do exchange information and make decisions accordingly.-I did a quick google under cell communication, and found the following, which I quote in full:-	The Evolution of Cell-to-Cell Communication in ...www.scoop.it/t/social-foraging/p/3867153222/the-evolution-of-cell...-From www.ploscompbiol.org - December 27, 2012 2:53 AM -"Traditionally microorganisms were considered to be autonomous organisms that could be studied in isolation. However, over the last decades cell-to-cell communication has been found to be ubiquitous. By secreting molecular signals in the extracellular environment microorganisms can indirectly assess the cell density and respond in accordance. In one of the best-studied microorganisms, Bacillus subtilis, the differentiation processes into a number of distinct cell types have been shown to depend on cell-to-cell communication. One of these cell types is the spore. Spores are metabolically inactive cells that are highly resistant against environmental stress. The onset of sporulation is dependent on cell-to-cell communication, as well as on a number of other environmental cues. By using individual-based simulations we examine when cell-to-cell communication that is involved in the onset of sporulation can evolve. We show that it evolves when three basic premises are satisfied. First, the population of cells has to affect the nutrient conditions. Second, there should be a time-lag between the moment that a cell decides to sporulate and the moment that it turns into a mature spore. Third, there has to be environmental variation. Cell-to-cell communication is a strategy to cope with environmental variation, by allowing cells to predict future environmental conditions. As a consequence, cells can anticipate environmental stress by initiating sporulation. Furthermore, signal production could be considered a cooperative trait and therefore evolves when it is not too costly to produce signal and when there are recurrent colony bottlenecks, which facilitate assortment. Finally, we also show that cell-to-cell communication can drive ecological diversification. Different ecotypes can evolve and be maintained due to frequency-dependent selection."-As with Margulis, the emphasis is on communication, and cooperation, decision-making, and most interestingly diversification. Perhaps you do not regard communication as the exchange of information.
 
DAVID: Your cellular plan is like sending a group of folks out on the field who don't know what game they are supposed to play.-I like this analogy, because it draws a clear dividing line between innovation and established patterns. How do you think games like football, baseball, cricket etc. originated? When living conditions were suitable, groups of humans got together and devised the games and the rules, and then they stuck to them (with minor variations as conditions dictated). Of course one might argue that it was your God who put the idea and the rules in their heads ... but you don't do so, because you believe humans are able to design things independently of God's planning. That, however, is precisely the scenario I am suggesting as an alternative to your preprogramming: that when living conditions demanded it (adaptation) or allowed for it (innovation), existing cell communities cooperated in order to design the new organs and the rules that govern them. Once the system is established, the players know precisely what game they have to play.-Yet again, you have sidestepped the fact that, since you believe evolution happened, your God must have preproprammed every innovation into the very first organisms, as well as the environmental changes that enabled them to come into being. And once more you claim that only this particular theistic interpretation makes sense. If I were a believer, I would find it far less convincing than the hypothesis that God created an intelligent mechanism (the cell) which over billions of years and through zillions of combinations devised its own evolutionary programmes. And if I were your God, I'm sure I'd find that scenario a good deal more interesting than yours!