Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A simple, general result for the variance of substitution number in
  molecular evolution   The number of substitutions (of nucleotides, amino acids, ...) that take
place during the evolution of a sequence is a stochastic variable of
fundamental importance in the field of molecular evolution. Although the mean
number of substitutions during molecular evolution of a sequence can be
estimated for a given substitution model, no simple solution exists for the
variance of this random variable. We show in this article that the computation
of the variance is as simple as that of the mean number of substitutions for
both short and long times. Apart from its fundamental importance, this result
can be used to investigate the dispersion index R , i.e. the ratio of the
variance to the mean substitution number, which is of prime importance in the
neutral theory of molecular evolution. By investigating large classes of
substitution models, we demonstrate that although R\ge1 , to obtain R
significantly larger than unity necessitates in general additional hypotheses
on the structure of the substitution model.

1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess