User:Jtwsaddress42/Projects/Project 2/Chapters/Chapter 5

Evolving Animals From Multicellularity

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Reversible multicellularity There are many forms of multicellularity that have arisen in all the major biological domains, but most of these have exhibited reversible developmental dynamics such that the multicellular colony, and its individual members or groups, could associate and disassociate in accordance with changing conditions; and thereby, oscillate between the collective and the individual, with selection still centered on the unicellular phenotype and the behavioral repertoire that facilitates multicellular association. Even in this architecturally primitive form, we can see the potential dynamism of multicellularity for creating new ecological niches - and, see the sophistication of the cellular behavioral repertoire on the individual, as well as collective, level. The late pioneering British eukaryotic evolutionary microbiolist and theorist Thomas Cavalier-Smith (October 21, 1942 - March 19, 2021), devoted a lifetime to organizing our understanding of the eukaryotic world and detailed countless examples of multicellularity in various unicellular species. Evolving Animals From Multicellularity "Evolving multicellularity is easy, especially in phototrophs and osmotrophs whose multicells feed like unicells. Evolving animals was much harder and unique;" - Thomas Cavalier-Smith (2017)

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