---
OA_place: repository
OA_type: green
_id: '21322'
abstract:
- lang: eng
text: Habitat fragmentation poses a significant risk to population survival, causing
both demographic stochasticity and genetic drift within local populations to increase,
thereby increasing genetic load. Higher load causes population numbers to decline,
which reduces the efficiency of selection and further increases load, resulting
in a positive feedback that may drive entire populations to extinction. Here,
we investigate this eco-evolutionary feedback in a metapopulation consisting of
local demes connected via migration, with individuals subject to deleterious mutation
at a large number of loci. We first analyze the determinants of load under soft
selection, where population sizes are fixed, and then build on this to understand
hard selection, where population sizes and load coevolve. We show that under soft
selection, very little gene flow (less than one migrant per generation) is enough
to prevent fixation of deleterious alleles. By contrast, much higher levels of
migration are required to mitigate load and prevent extinction when selection
is hard, with critical migration thresholds for metapopulation persistence increasing
sharply as the genome-wide deleterious mutation rate becomes comparable to the
baseline population growth rate. Moreover, critical migration thresholds are highest
if deleterious mutations have intermediate selection coefficients but lower if
alleles are predominantly recessive rather than additive (due to more efficient
purging of recessive load within local populations). Our analysis is based on
a combination of analytical approximations and simulations, allowing for a more
comprehensive understanding of the factors influencing load and extinction in
fragmented populations.
acknowledgement: 'This research was partially funded by the Austrian Science Fund
(FWF P-32896B) and DOC Fellowships of the Austrian Academy of Sciences: grants 26380
(O.O.) and 26293 (K.K.). We thank Nick Barton for useful comments on the chapter
in O.O.’s thesis that led to this article.'
article_processing_charge: No
article_type: original
author:
- first_name: Oluwafunmilola O
full_name: Olusanya, Oluwafunmilola O
id: 41AD96DC-F248-11E8-B48F-1D18A9856A87
last_name: Olusanya
orcid: 0000-0003-1971-8314
- first_name: Kseniia
full_name: Khudiakova, Kseniia
id: 4E6DC800-AE37-11E9-AC72-31CAE5697425
last_name: Khudiakova
orcid: 0000-0002-6246-1465
- first_name: Himani
full_name: Sachdeva, Himani
id: 42377A0A-F248-11E8-B48F-1D18A9856A87
last_name: Sachdeva
citation:
ama: Olusanya OO, Khudiakova K, Sachdeva H. Genetic load, eco-evolutionary feedback,
and extinction in metapopulations. The American Naturalist. 2025;205(6):617-636.
doi:10.1086/735562
apa: Olusanya, O. O., Khudiakova, K., & Sachdeva, H. (2025). Genetic load, eco-evolutionary
feedback, and extinction in metapopulations. The American Naturalist. University
of Chicago Press. https://doi.org/10.1086/735562
chicago: Olusanya, Oluwafunmilola O, Kseniia Khudiakova, and Himani Sachdeva. “Genetic
Load, Eco-Evolutionary Feedback, and Extinction in Metapopulations.” The American
Naturalist. University of Chicago Press, 2025. https://doi.org/10.1086/735562.
ieee: O. O. Olusanya, K. Khudiakova, and H. Sachdeva, “Genetic load, eco-evolutionary
feedback, and extinction in metapopulations,” The American Naturalist,
vol. 205, no. 6. University of Chicago Press, pp. 617–636, 2025.
ista: Olusanya OO, Khudiakova K, Sachdeva H. 2025. Genetic load, eco-evolutionary
feedback, and extinction in metapopulations. The American Naturalist. 205(6),
617–636.
mla: Olusanya, Oluwafunmilola O., et al. “Genetic Load, Eco-Evolutionary Feedback,
and Extinction in Metapopulations.” The American Naturalist, vol. 205,
no. 6, University of Chicago Press, 2025, pp. 617–36, doi:10.1086/735562.
short: O.O. Olusanya, K. Khudiakova, H. Sachdeva, The American Naturalist 205 (2025)
617–636.
corr_author: '1'
date_created: 2026-02-18T10:47:18Z
date_published: 2025-06-01T00:00:00Z
date_updated: 2026-04-07T08:45:14Z
day: '01'
department:
- _id: JaMa
- _id: NiBa
doi: 10.1086/735562
external_id:
pmid:
- '40446297 '
intvolume: ' 205'
issue: '6'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1101/2023.12.02.569702
month: '06'
oa: 1
oa_version: Preprint
page: 617-636
pmid: 1
project:
- _id: c08d3278-5a5b-11eb-8a69-fdb09b55f4b8
grant_number: P32896
name: Causes and consequences of population fragmentation
- _id: 34c872fe-11ca-11ed-8bc3-8534b82131e6
grant_number: '26380'
name: Polygenic Adaptation in a Metapopulation
- _id: 34d33d68-11ca-11ed-8bc3-ec13763c0ca8
grant_number: '26293'
name: The impact of deleterious mutations on small populations
publication: The American Naturalist
publication_identifier:
eissn:
- 1537-5323
issn:
- 0003-0147
publication_status: published
publisher: University of Chicago Press
quality_controlled: '1'
related_material:
record:
- id: '14732'
relation: earlier_version
status: public
scopus_import: '1'
status: public
title: Genetic load, eco-evolutionary feedback, and extinction in metapopulations
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 205
year: '2025'
...
---
OA_place: repository
OA_type: green
_id: '20056'
abstract:
- lang: eng
text: Theoretical studies have shown that stochasticity can affect the dynamics
of ecosystems in counterintuitive ways. However, without knowing the equations
governing the dynamics of populations or ecosystems, it is difficult to ascertain
the role of stochasticity in real datasets. Therefore, the inverse problem of
inferring the governing stochastic equations from datasets is important. Here,
we present an equation discovery methodology that takes time series data of state
variables as input and outputs a stochastic differential equation. We achieve
this by combining traditional approaches from stochastic calculus with the equation
discovery techniques. We demonstrate the generality of the method via several
applications. First, we deliberately choose various stochastic models with fundamentally
different governing equations, yet they produce nearly identical steady-state
distributions. We show that we can recover the correct underlying equations, and
thus infer the structure of their stability, accurately from the analysis of time
series data alone. We demonstrate our method on two real-world datasets—fish schooling
and single-cell migration—that have vastly different spatiotemporal scales and
dynamics. We illustrate various limitations and potential pitfalls of the method
and how to overcome them via diagnostic measures. Finally, we provide our open-source
code via a package named PyDaDDy (Python Library for Data-Driven Dynamics).
acknowledgement: V.G. acknowledges support from the Science and Engi-neering Research
Board, Department of Biotechnology,and the Indo-French Centre for the Promotion
of Ad-vanced Research (64T4-1). D.R.M. acknowledges supportfrom a Department of
Science and Technology (DST) In-novation in Science Pursuit for Inspired Research
(IN-SPIRE) Faculty Award. J.J. acknowledges support froma Humboldt postdoctoral
fellowship and the Heidelber-ger Akademie der Wissenschaften, Heidelberg, Germany.D.B.B.
acknowledges support from the NOMIS Founda-tion and an European Molecular Biology
Organization(EMBO) postdoctoral fellowship (ALTF 343-2022). A.N.and S.P. acknowledge
support from Ministry of Educa-tion (MoE) PhD fellowships. We thank Ashrit Mangal-wedhekar,
Vivek Jadhav, Shikhara Bhat, Cassandre Aimon,and Harishankar Muppirala for comments
on the manu-script and code. We thank Kollegala Sharma for his inputon the Kannada
translation of the title and abstract.Data-Driven Model Discovery E115
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Arshed
full_name: Nabeel, Arshed
last_name: Nabeel
- first_name: Ashwin
full_name: Karichannavar, Ashwin
last_name: Karichannavar
- first_name: Shuaib
full_name: Palathingal, Shuaib
last_name: Palathingal
- first_name: Jitesh
full_name: Jhawar, Jitesh
last_name: Jhawar
- first_name: David
full_name: Brückner, David
id: e1e86031-6537-11eb-953a-f7ab92be508d
last_name: Brückner
orcid: 0000-0001-7205-2975
- first_name: Danny
full_name: Raj M, Danny
last_name: Raj M
- first_name: Vishwesha
full_name: Guttal, Vishwesha
last_name: Guttal
citation:
ama: Nabeel A, Karichannavar A, Palathingal S, et al. Discovering stochastic dynamical
equations from ecological time series data. The American Naturalist. 2025;205(4):E100-E117.
doi:10.1086/734083
apa: Nabeel, A., Karichannavar, A., Palathingal, S., Jhawar, J., Brückner, D., Raj
M, D., & Guttal, V. (2025). Discovering stochastic dynamical equations from
ecological time series data. The American Naturalist. University of Chicago
Press. https://doi.org/10.1086/734083
chicago: Nabeel, Arshed, Ashwin Karichannavar, Shuaib Palathingal, Jitesh Jhawar,
David Brückner, Danny Raj M, and Vishwesha Guttal. “Discovering Stochastic Dynamical
Equations from Ecological Time Series Data.” The American Naturalist. University
of Chicago Press, 2025. https://doi.org/10.1086/734083.
ieee: A. Nabeel et al., “Discovering stochastic dynamical equations from
ecological time series data,” The American Naturalist, vol. 205, no. 4.
University of Chicago Press, pp. E100–E117, 2025.
ista: Nabeel A, Karichannavar A, Palathingal S, Jhawar J, Brückner D, Raj M D, Guttal
V. 2025. Discovering stochastic dynamical equations from ecological time series
data. The American Naturalist. 205(4), E100–E117.
mla: Nabeel, Arshed, et al. “Discovering Stochastic Dynamical Equations from Ecological
Time Series Data.” The American Naturalist, vol. 205, no. 4, University
of Chicago Press, 2025, pp. E100–17, doi:10.1086/734083.
short: A. Nabeel, A. Karichannavar, S. Palathingal, J. Jhawar, D. Brückner, D. Raj
M, V. Guttal, The American Naturalist 205 (2025) E100–E117.
date_created: 2025-07-21T08:37:27Z
date_published: 2025-04-01T00:00:00Z
date_updated: 2025-09-30T14:14:43Z
day: '01'
department:
- _id: EdHa
doi: 10.1086/734083
external_id:
arxiv:
- '2205.02645'
isi:
- '001433250500001'
pmid:
- '40179429'
intvolume: ' 205'
isi: 1
issue: '4'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.2205.02645
month: '04'
oa: 1
oa_version: Preprint
page: E100-E117
pmid: 1
project:
- _id: 34e2a5b5-11ca-11ed-8bc3-b2265616ef0b
grant_number: ALTF 343-2022
name: A mechano-chemical theory for stem cell fate decisions in organoid development
publication: The American Naturalist
publication_identifier:
eissn:
- 1537-5323
issn:
- 0003-0147
publication_status: published
publisher: University of Chicago Press
quality_controlled: '1'
related_material:
record:
- id: '20121'
relation: software
status: public
status: public
title: Discovering stochastic dynamical equations from ecological time series data
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 205
year: '2025'
...
---
_id: '3393'
abstract:
- lang: eng
text: 'Unlike unconditionally advantageous “Fisherian” variants that tend to spread
throughout a species range once introduced anywhere, “bistable” variants, such
as chromosome translocations, have two alternative stable frequencies, absence
and (near) fixation. Analogous to populations with Allee effects, bistable variants
tend to increase locally only once they become sufficiently common, and their
spread depends on their rate of increase averaged over all frequencies. Several
proposed manipulations of insect populations, such as using Wolbachia or “engineered
underdominance” to suppress vector-borne diseases, produce bistable rather than
Fisherian dynamics. We synthesize and extend theoretical analyses concerning three
features of their spatial behavior: rate of spread, conditions to initiate spread
from a localized introduction, and wave stopping caused by variation in population
densities or dispersal rates. Unlike Fisherian variants, bistable variants tend
to spread spatially only for particular parameter combinations and initial conditions.
Wave initiation requires introduction over an extended region, while subsequent
spatial spread is slower than for Fisherian waves and can easily be halted by
local spatial inhomogeneities. We present several new results, including robust
sufficient conditions to initiate (and stop) spread, using a one-parameter cubic
approximation applicable to several models. The results have both basic and applied
implications.'
article_processing_charge: No
article_type: original
author:
- first_name: Nicholas H
full_name: Barton, Nicholas H
id: 4880FE40-F248-11E8-B48F-1D18A9856A87
last_name: Barton
orcid: 0000-0002-8548-5240
- first_name: Michael
full_name: Turelli, Michael
last_name: Turelli
citation:
ama: 'Barton NH, Turelli M. Spatial waves of advance with bistable dynamics: Cytoplasmic
and genetic analogues of Allee effects. American Naturalist. 2011;178(3):E48-E75.
doi:10.1086/661246'
apa: 'Barton, N. H., & Turelli, M. (2011). Spatial waves of advance with bistable
dynamics: Cytoplasmic and genetic analogues of Allee effects. American Naturalist.
The University of Chicago Press. https://doi.org/10.1086/661246'
chicago: 'Barton, Nicholas H, and Michael Turelli. “Spatial Waves of Advance with
Bistable Dynamics: Cytoplasmic and Genetic Analogues of Allee Effects.” American
Naturalist. The University of Chicago Press, 2011. https://doi.org/10.1086/661246.'
ieee: 'N. H. Barton and M. Turelli, “Spatial waves of advance with bistable dynamics:
Cytoplasmic and genetic analogues of Allee effects,” American Naturalist,
vol. 178, no. 3. The University of Chicago Press, pp. E48–E75, 2011.'
ista: 'Barton NH, Turelli M. 2011. Spatial waves of advance with bistable dynamics:
Cytoplasmic and genetic analogues of Allee effects. American Naturalist. 178(3),
E48–E75.'
mla: 'Barton, Nicholas H., and Michael Turelli. “Spatial Waves of Advance with Bistable
Dynamics: Cytoplasmic and Genetic Analogues of Allee Effects.” American Naturalist,
vol. 178, no. 3, The University of Chicago Press, 2011, pp. E48–75, doi:10.1086/661246.'
short: N.H. Barton, M. Turelli, American Naturalist 178 (2011) E48–E75.
date_created: 2018-12-11T12:03:05Z
date_published: 2011-09-01T00:00:00Z
date_updated: 2025-09-30T08:43:28Z
day: '01'
ddc:
- '570'
department:
- _id: NiBa
doi: 10.1086/661246
external_id:
isi:
- '000294256800001'
file:
- access_level: open_access
checksum: 7fd22a2ef3321a6fca6a439b3be5d8f4
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:08:31Z
date_updated: 2020-07-14T12:46:11Z
file_id: '4692'
file_name: IST-2016-554-v1+1_BartonTurelli2011_copy.pdf
file_size: 629130
relation: main_file
file_date_updated: 2020-07-14T12:46:11Z
has_accepted_license: '1'
intvolume: ' 178'
isi: 1
issue: '3'
language:
- iso: eng
month: '09'
oa: 1
oa_version: Submitted Version
page: E48 - E75
publication: American Naturalist
publication_identifier:
eissn:
- 1537-5323
issn:
- 0003-0147
publication_status: published
publisher: The University of Chicago Press
publist_id: '3214'
pubrep_id: '554'
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Spatial waves of advance with bistable dynamics: Cytoplasmic and genetic analogues
of Allee effects'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 178
year: '2011'
...
---
_id: '3659'
abstract:
- lang: eng
text: We develop models of the rates of evolution at sex-linked and autosomal loci
and of the rates of fixation of chromosomal rearrangements involving sex chromosomes
and autosomes. We show that the substitution of selectively favorable mutations
often proceeds more rapidly for X- or Y-linked loci than for the autosomes, provided
that mutations are recessive or partially recessive on the average. Selection
acting on a quantitative character is expected to result in similar long-term
rates of gene substitution for X-linked and autosomal loci, unless there is strong
directional dominance. Short-term responses to such selection often preferentially
fix alleles at autosomal loci. The fixation of slightly deleterious alleles by
random drift and the stochastic turnover of alleles at loci controlling quantitative
characters under stabilizing selection usually proceed somewhat more slowly at
sex-linked loci. In contrast, the fixation of underdominant chromosomal rearrangements
by random genetic drift is faster with sex linkage. Sex-specific selection may
also differentially favor the fixation of sex-linked rearrangements. These results
are discussed in relation to genetic and cytological data on species differences.
We show that the frequently disproportionate effects of the sex chromosomes on
interspecific inviability or sterility are consistent with the hypothesis that
the gene differences concerned involve recessive or partially recessive alleles
fixed by selection. Haldane's rule is readily interpreted in this light. There
is little evidence for strong effects of the sex chromosomes on quantitative characters
in interspecific crosses, in accordance with our theoretical results. Thus, the
evolution of reproductive isolation may not be the byproduct of selective change
in additively inherited, polygenic traits. Rather, it may be due mainly to the
fixation of favorable mutations whose effects on fitness reflect locus-specific
effects on the phenotype. These mutations behave as major genes in the sense of
contributing the bulk of the genetic variance in the characters that they control
during the course of the mutations' substitution. The data on the genetics of
short-term responses to selection in Drosophila are hard to interpret, but, in
accordance with theory, these responses do not usually seem to involve the X chromosome
disproportionately. In some groups, there is evidence for a disproportionate role
of the sex chromosomes in chromosomal changes, but others show no clear pattern.
Factors that may distort the expectations of the simple models of chromosomal
evolution are discussed.
article_processing_charge: No
article_type: original
author:
- first_name: Brian
full_name: Charlesworth, Brian
last_name: Charlesworth
- first_name: Jerry
full_name: Coyne, Jerry
last_name: Coyne
- first_name: Nicholas H
full_name: Barton, Nicholas H
id: 4880FE40-F248-11E8-B48F-1D18A9856A87
last_name: Barton
orcid: 0000-0002-8548-5240
citation:
ama: Charlesworth B, Coyne J, Barton NH. The relative rates of evolution of sex
chromosomes and autosomes. American Naturalist. 1987;130(1):113-146. doi:10.1086/284701
apa: Charlesworth, B., Coyne, J., & Barton, N. H. (1987). The relative rates
of evolution of sex chromosomes and autosomes. American Naturalist. University
of Chicago Press. https://doi.org/10.1086/284701
chicago: Charlesworth, Brian, Jerry Coyne, and Nicholas H Barton. “The Relative
Rates of Evolution of Sex Chromosomes and Autosomes.” American Naturalist.
University of Chicago Press, 1987. https://doi.org/10.1086/284701.
ieee: B. Charlesworth, J. Coyne, and N. H. Barton, “The relative rates of evolution
of sex chromosomes and autosomes,” American Naturalist, vol. 130, no. 1.
University of Chicago Press, pp. 113–146, 1987.
ista: Charlesworth B, Coyne J, Barton NH. 1987. The relative rates of evolution
of sex chromosomes and autosomes. American Naturalist. 130(1), 113–146.
mla: Charlesworth, Brian, et al. “The Relative Rates of Evolution of Sex Chromosomes
and Autosomes.” American Naturalist, vol. 130, no. 1, University of Chicago
Press, 1987, pp. 113–46, doi:10.1086/284701.
short: B. Charlesworth, J. Coyne, N.H. Barton, American Naturalist 130 (1987) 113–146.
date_created: 2018-12-11T12:04:29Z
date_published: 1987-01-01T00:00:00Z
date_updated: 2022-02-04T12:11:20Z
day: '01'
doi: 10.1086/284701
extern: '1'
intvolume: ' 130'
issue: '1'
language:
- iso: eng
main_file_link:
- url: ' http://www.jstor.org/stable/2461884'
month: '01'
oa_version: None
page: 113 - 146
publication: American Naturalist
publication_identifier:
eissn:
- 1537-5323
issn:
- 0003-0147
publication_status: published
publisher: University of Chicago Press
publist_id: '2724'
quality_controlled: '1'
status: public
title: The relative rates of evolution of sex chromosomes and autosomes
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 130
year: '1987'
...