Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The rise and fall of the Phytophthora infestans lineage that triggered
  the Irish potato famine   Phytophthora infestans, the cause of potato late blight, is infamous for
having triggered the Irish Great Famine in the 1840s. Until the late 1970s, P.
infestans diversity outside of its Mexican center of origin was low, and one
scenario held that a single strain, US-1, had dominated the global population
for 150 years; this was later challenged based on DNA analysis of historical
herbarium specimens. We have compared the genomes of 11 herbarium and 15 modern
strains. We conclude that the nineteenth century epidemic was caused by a
unique genotype, HERB-1, that persisted for over 50 years. HERB-1 is distinct
from all examined modern strains, but it is a close relative of US-1, which
replaced it outside of Mexico in the twentieth century. We propose that HERB-1
and US-1 emerged from a metapopulation that was established in the early 1800s
outside of the species' center of diversity.

17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc