  Theoretical understanding of evolutionary dynamics in spatially structured
populations often relies on non-spatial models. Biofilms are among such
populations where a more accurate understanding is of theoretical interest and
can reveal new solutions to existing challenges. Here, we studied how the
geometry of the environment affects the evolutionary dynamics of expanding
populations, using the Eden model. Our results show that fluctuations of
sub-populations during range expansion in 2D and 3D environments are not
Brownian. Furthermore, we found that the substrate's geometry interferes with
the evolutionary dynamics of populations that grow upon it. Inspired by these
findings, we propose a periodically wedged pattern on surfaces prone to develop
biofilms. On such patterned surfaces, natural selection becomes less effective
and beneficial mutants would have a harder time establishing. Additionally,
this modification accelerates genetic drift and leads to less diverse biofilms.
Both interventions are highly desired for biofilms.
