Germ lines and extended selection during the evolutionary transition to multicellularity

Autor: Caroline J. Rose
Rok vydání: 2020
Předmět:
Zdroj: Journal of Experimental Zoology Part B: Molecular and Developmental Evolution. 336:680-686
ISSN: 1552-5015
1552-5007
DOI: 10.1002/jez.b.22985
Popis: The major evolutionary transitions from unicellular organisms to multicellularity resulted in a profusion of complex life forms. During the transition from single cells to multicellular life, groups of cells acquired the capacity for reproduction as discrete units; however, the selective causes and underlying mechanisms remain debated. One perspective views the evolution of multicellularity as a shift in the timescale at which natural selection primarily operates-from that of individual cells to the timescale of reproducing groups of cells. Therefore, a distinguishing feature of multicellular reproduction, as opposed to simple growth of a multicellular collective, is that the capacity for reproduction must develop over a timescale that is greater than the reproductive timescale of a single cell. Here, I suggest that the emergence of specialized reproductive cells (the germ line) was an essential first stage of the evolutionary transition to multicellularity because it imposed the necessary "delay"-allowing natural selection to operate over the longer timescale of a multicellular life cycle, ultimately resulting in the evolution of complex multicellular organisms. This perspective highlights the possibility that the ubiquity of a germ-soma distinction among complex multicellular organisms reflects the fact that such life cycles, on first emergence, had the greatest propensity to participate in Darwinian evolution.
Databáze: OpenAIRE
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