  A great number of biological organisms live in aqueous environments. Major
evolutionary transitions, including the emergence of life itself, likely
occurred in such environments. While the chemical aspects of the role of water
in biology are well-studied, the effects of water's physical characteristics on
evolutionary events, such as the control of population structure via its rich
transport properties, are less clear. Evolutionary transitions such as the
emergence of the first cells and of multicellularity, require cooperation among
groups of individuals. However, evolution of cooperation faces challenges in
unstructured "well-mixed" populations, as parasites quickly overwhelm
cooperators. Models that assume population structure to promote cooperation
envision such structure to arise from spatial "lattice" models (e.g. surface
bound individuals) or compartmentalization models, often realized as
protocells. Here we study the effect of turbulent motions in spatial models,
and propose that coherent structures, i.e. flow patterns which trap fluid and
arise naturally in turbulent flows, may serve many of the properties associated
with compartments--collocalization, division, and merging--and thought to play
a key role in the origins of life and other evolutionary transitions. These
results suggest that group selection models may be applicable with fewer
physical and chemical constraints than previously thought, and apply much more
widely in aqueous environments.
