Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous natural selection in a model for spatially distributed
  interacting populations   We present an individual-based model for two interacting populations
diffusing on lattices in which a strong natural selection develops
spontaneously. The models combine traditional local predator-prey dynamics with
random walks. Individual's mobility is considered as an inherited trait. Small
variations upon inheritance, mimicking mutations, provide variability on which
natural selection may act. Although the dynamic rules defining the models do
not explicitly favor any mobility values, we found that the average mobility of
both populations tend to be maximized in various situations. In some situations
there is evidence of polymorphism, indicated by an adaptive landscape with many
local maxima. We provide evidence relating selective pressure for high mobility
with pattern formation.

34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg