---
_id: '315'
abstract:
- lang: eng
text: 'More than 100 years after Grigg’s influential analysis of species’ borders,
the causes of limits to species’ ranges still represent a puzzle that has never
been understood with clarity. The topic has become especially important recently
as many scientists have become interested in the potential for species’ ranges
to shift in response to climate change—and yet nearly all of those studies fail
to recognise or incorporate evolutionary genetics in a way that relates to theoretical
developments. I show that range margins can be understood based on just two measurable
parameters: (i) the fitness cost of dispersal—a measure of environmental heterogeneity—and
(ii) the strength of genetic drift, which reduces genetic diversity. Together,
these two parameters define an ‘expansion threshold’: adaptation fails when genetic
drift reduces genetic diversity below that required for adaptation to a heterogeneous
environment. When the key parameters drop below this expansion threshold locally,
a sharp range margin forms. When they drop below this threshold throughout the
species’ range, adaptation collapses everywhere, resulting in either extinction
or formation of a fragmented metapopulation. Because the effects of dispersal
differ fundamentally with dimension, the second parameter—the strength of genetic
drift—is qualitatively different compared to a linear habitat. In two-dimensional
habitats, genetic drift becomes effectively independent of selection. It decreases
with ‘neighbourhood size’—the number of individuals accessible by dispersal within
one generation. Moreover, in contrast to earlier predictions, which neglected
evolution of genetic variance and/or stochasticity in two dimensions, dispersal
into small marginal populations aids adaptation. This is because the reduction
of both genetic and demographic stochasticity has a stronger effect than the cost
of dispersal through increased maladaptation. The expansion threshold thus provides
a novel, theoretically justified, and testable prediction for formation of the
range margin and collapse of the species’ range.'
article_number: e2005372
author:
- first_name: Jitka
full_name: Polechova, Jitka
id: 3BBFB084-F248-11E8-B48F-1D18A9856A87
last_name: Polechova
orcid: 0000-0003-0951-3112
citation:
ama: Polechova J. Is the sky the limit? On the expansion threshold of a species’
range. PLoS Biology. 2018;16(6). doi:10.1371/journal.pbio.2005372
apa: Polechova, J. (2018). Is the sky the limit? On the expansion threshold of a
species’ range. PLoS Biology. Public Library of Science. https://doi.org/10.1371/journal.pbio.2005372
chicago: Polechova, Jitka. “Is the Sky the Limit? On the Expansion Threshold of
a Species’ Range.” PLoS Biology. Public Library of Science, 2018. https://doi.org/10.1371/journal.pbio.2005372.
ieee: J. Polechova, “Is the sky the limit? On the expansion threshold of a species’
range,” PLoS Biology, vol. 16, no. 6. Public Library of Science, 2018.
ista: Polechova J. 2018. Is the sky the limit? On the expansion threshold of a species’
range. PLoS Biology. 16(6), e2005372.
mla: Polechova, Jitka. “Is the Sky the Limit? On the Expansion Threshold of a Species’
Range.” PLoS Biology, vol. 16, no. 6, e2005372, Public Library of Science,
2018, doi:10.1371/journal.pbio.2005372.
short: J. Polechova, PLoS Biology 16 (2018).
date_created: 2018-12-11T11:45:46Z
date_published: 2018-06-15T00:00:00Z
date_updated: 2023-02-23T14:10:16Z
day: '15'
ddc:
- '576'
department:
- _id: NiBa
doi: 10.1371/journal.pbio.2005372
file:
- access_level: open_access
checksum: 908c52751bba30c55ed36789e5e4c84d
content_type: application/pdf
creator: dernst
date_created: 2019-01-22T08:30:03Z
date_updated: 2020-07-14T12:46:01Z
file_id: '5870'
file_name: 2017_PLOS_Polechova.pdf
file_size: 6968201
relation: main_file
file_date_updated: 2020-07-14T12:46:01Z
has_accepted_license: '1'
intvolume: ' 16'
issue: '6'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
publication: PLoS Biology
publication_identifier:
issn:
- '15449173'
publication_status: published
publisher: Public Library of Science
publist_id: '7550'
quality_controlled: '1'
related_material:
record:
- id: '9839'
relation: research_data
status: public
scopus_import: 1
status: public
title: Is the sky the limit? On the expansion threshold of a species’ range
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 16
year: '2018'
...