More about how evolution works: multicellularity (Evolution)

by David Turell , Friday, November 06, 2015, 01:30 (3304 days ago) @ dhw


> dhw: As I understood it, he was basing his “suppositions” on his observation of volvocine algae: “Volvocine algae are aquatic, flagellated eukaryotes that range in complexity from unicellular species to a variety of colonial forms to multicellular Volvox, some of which boast up to 50,000 cells. This transition involved a series of key innovations, including cell-cell adhesion, inversion, and differentiation of somatic and germ cell lines. Two species in particular have become models for the evolution of multicellularity—the single-celled Chlamydomonas reinhardtii and the 2,000-or-so-celled Volvox carteri.” 
> “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.
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> Of course it's conjecture, but why are your own “suppositions” more valid than his?-He is interpreting conflict. I see no proof.
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> dhw: For me this is evidence of common descent, and taken in conjunction with other quotes that you have ignored, I asked: “If multicellularity evolved 25 different times, which of these is more likely: 1) that the 25 times were all preprogrammed for the sake of producing one species (humans), or 2) different cellular communities interacted and cooperated autonomously to work out different combinations (the vast variety of species extant and extinct)?” Preprogramming = planning. -Simon Conway Morris would call this convergence, which in his eyes means humans must arrive. "Life's Solution; Inevitable Humans in a Lonely Universe" 2003 U. Cambridge Press. I didn't answer because the article presents pre-planning in the genetic descriptions.-Why don't you comment on the articles I present, like in today's material molecule transport in the cell?