Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A conditional likelihood is required to estimate the selection
  coefficient in ancient DNA   Time-series of allele frequencies are a useful and unique set of data to
determine the strength of natural selection on the background of genetic drift.
Technically, the selection coefficient is estimated by means of a likelihood
function built under the hypothesis that the available trajectory spans a
sufficiently large portion of the fitness landscape. Especially for ancient
DNA, however, often only one single such trajectories is available and the
coverage of the fitness landscape is very limited. In fact, one single
trajectory is more representative of a process conditioned both in the initial
and in the final condition than of a process free to visit the available
fitness landscape. Based on two models of population genetics, here we show how
to build a likelihood function for the selection coefficient that takes the
statistical peculiarity of single trajectories into account. We show that this
conditional likelihood delivers a precise estimate of the selection coefficient
also when allele frequencies are close to fixation whereas the unconditioned
likelihood fails. Finally, we discuss the fact that the traditional,
unconditioned likelihood always delivers an answer, which is often
unfalsifiable and appears reasonable also when it is not correct.

17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
2
The categories of this paper are: math