More Denton: Another review of Denton's new book (Introduction)

by dhw, Sunday, May 29, 2016, 13:42 (3100 days ago) @ David Turell

dhw: It is you who keep quoting authors who flog the dead horse of gradualism. I agree with you entirely on the subject of “magical” saltations, but how often do we have to repeat that nobody can explain them?
DAVID: Belief in God does. Remember I'm on his side.-You are right. Belief in chance or in an autonomous inventive mechanism also explains them. I should have said that nobody knows which is the true explanation.-dhw: Of course it's saltation, but in this particular instance, Margulis's theory did not involve plotting. She suggests that the symbiosis originally took place by chance. The intelligence comes in with the recognition of mutual benefit, which then leads to further exploration of the potential benefits of symbiosis and cooperation. 

DAVID: Since when is natural selection a recognition of 'mutual benefit'? Bacteria don't think.-As usual, you state your opinion as if it were a fact. Natural selection does not preclude thought! Natural selection merely describes the process by which things survive or don't survive. If organisms find they benefit from something - whether it's symbiosis, sexual reproduction, vision, smell, nest-building, migration, parasitism - that “something” will survive. You say bacteria are automatons that don't know what they're doing. And yet you are prepared to grant autonomy to their multicellular descendants, even to the extent that they create functioning “complexifications” which your God may subsequently approve of (i.e. which he did not programme for them). Why should cells in communities be able to think for themselves and communicate with one another, but single cells can't?-DAVID: The Margolis theory cannot tell us whether it was chance engulfment, or God's saltation. -True. But you had ridiculed the idea of bacteria “plotting” to become multicellular, and I was explaining that there was no “plot” in Margulis's theory - even though she believed in bacterial intelligence. She attributed the beginnings to chance, not a “plot”. And I pointed out that the intelligence (perhaps God-given) came into play with recognition of the mutual benefit.-DAVID: That the newly combined organism had a better reproductive and survival fitness is all that was needed to establish a new form.-A better reproductive system = improvement. Better survival fitness, no, because unicellular bacteria have survived to this day. The whole point is that multicellularity allowed for an almost infinitely expandable range of life forms - a big improvement over the limitations of the single cell. Hence the higgledy-piggledy bush of evolution.