Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The evolution and distribution of species body size   The distribution of species body size within taxonomic groups exhibits a
heavy right-tail extending over many orders of magnitude, where most species
are significantly larger than the smallest species. We provide a simple model
of cladogenetic diffusion over evolutionary time that omits explicit mechanisms
for inter-specific competition and other microevolutionary processes yet fully
explains the shape of this distribution. We estimate the model's parameters
from fossil data and find that it robustly reproduces the distribution of 4002
mammal species from the late Quaternary. The observed fit suggests that the
asymmetric distribution arises from a fundamental tradeoff between the
short-term selective advantages (Cope's rule) and long-term selective risks of
increased species body size, in the presence of a taxon-specific lower limit on
body size.

11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th