Patterns of Species Ranges, Speciation, and Extinction
Authored by Aysegul Birand, Aaron Vose, Sergey Gavrilets
Date Published: 2012
DOI: 10.1086/663202
Sponsors:
United States National Institutes of Health (NIH)
Platforms:
C
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
The exact nature of the relationship among species range sizes, speciation, and extinction events is not well understood. The factors
that promote larger ranges, such as broad niche widths and high
dispersal abilities, could increase the likelihood of encountering new
habitats but also prevent local adaptation due to high gene flow.
Similarly, low dispersal abilities or narrower niche widths could cause
populations to be isolated, but such populations may lack advantageous
mutations due to low population sizes. Here we present a large-scale, spatially explicit, individual-based model addressing the relationships
between species ranges, speciation, and extinction. We followed the
evolutionary dynamics of hundreds of thousands of diploid individuals
for 200,000 generations. Individuals adapted to multiple resources and
formed ecological species in a multidimensional trait space. These
species varied in niche widths, and we observed the coexistence of
generalists and specialists on a few resources. Our model shows that
species ranges correlate with dispersal abilities but do not change with
the strength of fitness trade-offs; however, high dispersal abilities
and low resource utilization costs, which favored broad niche widths, have a strong negative effect on speciation rates. An unexpected result
of our model is the strong effect of underlying resource distributions
on speciation: in highly fragmented landscapes, speciation rates are
reduced.
Tags
sexual selection
sympatric speciation
Mathematical-models
Ecological speciation
Adaptive radiation
Interspecific competition
Environmental gradients
Geographic-distribution
Size distributions
Abundance distribution