Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Punctuated equilibrium in an evolving bacterial population   Recently, Lenski et al have carried out an experiment on bacterial evolution.
Their findings support the theory of punctuated equilibrium in biological
evolution. We show that the M=2 Bak-Sneppen model can explain some of the
experimental results in a qualitative manner.

37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph