Why have aggregative multicellular organisms stayed simple?

Autor: Márquez-Zacarías P; Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, USA. pedromaz@gatech.edu.; School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA. pedromaz@gatech.edu., Conlin PL; School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA., Tong K; Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, USA.; School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA., Pentz JT; Department of Molecular Biology, Umeå University, Umeå, 90187, Sweden., Ratcliff WC; School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA. ratcliff@gatech.edu.
Jazyk: angličtina
Zdroj: Current genetics [Curr Genet] 2021 Dec; Vol. 67 (6), pp. 871-876. Date of Electronic Publication: 2021 Jun 10.
DOI: 10.1007/s00294-021-01193-0
Abstrakt: Multicellularity has evolved numerous times across the tree of life. One of the most fundamental distinctions among multicellular organisms is their developmental mode: whether they stay together during growth and develop clonally, or form a group through the aggregation of free-living cells. The five eukaryotic lineages to independently evolve complex multicellularity (animals, plants, red algae, brown algae, and fungi) all develop clonally. This fact has largely been explained through social evolutionary theory's lens of cooperation and conflict, where cheating within non-clonal groups has the potential to undermine multicellular adaptation. Multicellular organisms that form groups via aggregation could mitigate the costs of cheating by evolving kin recognition systems that prevent the formation of chimeric groups. However, recent work suggests that selection for the ability to aggregate quickly may constrain the evolution of highly specific kin recognition, sowing the seeds for persistent evolutionary conflict. Importantly, other features of aggregative multicellular life cycles may independently act to constrain the evolution of complex multicellularity. All known aggregative multicellular organisms are facultatively multicellular (as opposed to obligately multicellular), allowing unicellular-level adaptation to environmental selection. Because they primarily exist in a unicellular state, it may be difficult for aggregative multicellular organisms to evolve multicellular traits that carry pleiotropic cell-level fitness costs. Thus, even in the absence of social conflict, aggregative multicellular organisms may have limited potential for the evolution of complex multicellularity.
(© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE