Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phenotypic evolution studied by layered stochastic differential
  equations   Time series of cell size evolution in unicellular marine algae (division
Haptophyta; Coccolithus lineage), covering 57 million years, are studied by a
system of linear stochastic differential equations of hierarchical structure.
The data consists of size measurements of fossilized calcite platelets
(coccoliths) that cover the living cell, found in deep-sea sediment cores from
six sites in the world oceans and dated to irregular points in time. To
accommodate biological theory of populations tracking their fitness optima, and
to allow potentially interpretable correlations in time and space, the model
framework allows for an upper layer of partially observed site-specific
population means, a layer of site-specific theoretical fitness optima and a
bottom layer representing environmental and ecological processes. While the
modeled process has many components, it is Gaussian and analytically tractable.
A total of 710 model specifications within this framework are compared and
inference is drawn with respect to model structure, evolutionary speed and the
effect of global temperature.

28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th