More about how evolution works: multicellularity (Evolution)

by David Turell , Wednesday, November 04, 2015, 23:31 (3305 days ago) @ dhw

David's comment: Very long and complex article. Looks like pre-planning to me. The discussion about supposed cooperation and conflict between cells as multicellularity develops makes me wonder what the author was smoking.-> dhw: As far as pre-planning is concerned, here are three more quotes: 
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> “But such transitions are not always smooth, as [b]conflict can arise when selfish mutations result in cheaters that attempt to benefit from the group without contributing their fair share.” 
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> “To defend themselves against such cheating, these new kinds of individuals must evolve mechanisms of conflict mediation.”
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> “These recurrent mutations in Volvox suggest that “the conflict between the individual cells and the interest of colony may still be going on,” he adds. Such conflict may limit the organism's complexity, as selection on individual cells battles with the whole organism's attempt to survive and reproduce, suggesting that perhaps the evolution of advanced multicellularity wasn't so easy after all.”
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> Sounds like individual intelligences to me. Why would your God preplan such conflicts if all he wanted to do was create humans? Ah, but you think the researchers have been smoking something, because how could cells possibly be individual and intelligent when the chances are only 50/50 and you happen to know which 50 is correct?-All of the above quotes are suppositions. Please read them closely. Why do you think I asked what he was smoking? What conflict? Bad mutations result in death, and most mutations end up in loss of information. Now he wants cells fighting with each other as they become cooperative communities! I guess he was there watching as multicellularity developed.-Quote miner! You ignored this quote I presented which is the info that made the pre-planning point:-"These genes that we previously thought were associated with complex multicellular animals really have to do with basic multicellular functions—to get the simplest multicellular animals, you have to have these genes present,” says Srivastava, who coauthored the analysis.-"As some of the most ancient animals, sponges can provide information regarding the evolution of the metazoan lineage, but for true insights about the origin of multicellularity, scientists must look even further back on the evolutionary tree. Choanoflagellates, unicellular organisms that look remarkably similar to the feeding structures of sponges, are the closest living relatives of metazoans. It turns out that they also share a number of genes once thought to be unique to multicellular animals. Tyrosine kinases (TK), for example, enzymes that function in cell-cell interactions and regulation of development in animals, were identified in the choanoflagellates in the early part of this decade, and the first sequenced choanoflagellate genome, published in 2008, revealed that they have more TK genes than any animal—and many other components of the TK signaling pathway as well."