---
_id: '3656'
abstract:
- lang: eng
text: We have analysed the role of sampling drift in inducing shifts between alternative
adaptive peaks, in small and rapidly growing populations. Using a simple model
of disruptive selection on a polygenic character, we calculate the net probabilityofapeakshift.
If the growth rate is high, theprobabilityofashiftina growing population is insensitive
to selection on the character. Assuming that the character is effectively neutral
during the brief initial increase, we find that theprobabilityofapeakshift is
given by theprobabilityof finding a standard normal variate greater than √2ΔV
where ΔV is the reduction in additive genetic variance during the growth period.
This result holds for arbitrary pattern of increase in size, provided that the
rate of increase is high enough for selection to be negligible, and the character
depends on a large number of loci. Comparing theprobabilityofpeakshiftsin founding
populations with the rate ofshiftsin static and allopatric populations it appears
that although strongly selected shifts are only likely to occur ina growing population,
a static population is a more congenial setting for adaptive shifts.
article_processing_charge: No
article_type: original
author:
- first_name: Shahin
full_name: Rouhani, Shahin
last_name: Rouhani
- 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: Rouhani S, Barton NH. The probability of peak shifts in a founder population.
Journal of Theoretical Biology. 1987;126(1):51-62. doi:10.1016/S0022-5193(87)80100-5
apa: Rouhani, S., & Barton, N. H. (1987). The probability of peak shifts in
a founder population. Journal of Theoretical Biology. Elsevier. https://doi.org/10.1016/S0022-5193(87)80100-5
chicago: Rouhani, Shahin, and Nicholas H Barton. “The Probability of Peak Shifts
in a Founder Population.” Journal of Theoretical Biology. Elsevier, 1987.
https://doi.org/10.1016/S0022-5193(87)80100-5.
ieee: S. Rouhani and N. H. Barton, “The probability of peak shifts in a founder
population,” Journal of Theoretical Biology, vol. 126, no. 1. Elsevier,
pp. 51–62, 1987.
ista: Rouhani S, Barton NH. 1987. The probability of peak shifts in a founder population.
Journal of Theoretical Biology. 126(1), 51–62.
mla: Rouhani, Shahin, and Nicholas H. Barton. “The Probability of Peak Shifts in
a Founder Population.” Journal of Theoretical Biology, vol. 126, no. 1,
Elsevier, 1987, pp. 51–62, doi:10.1016/S0022-5193(87)80100-5.
short: S. Rouhani, N.H. Barton, Journal of Theoretical Biology 126 (1987) 51–62.
date_created: 2018-12-11T12:04:28Z
date_published: 1987-05-07T00:00:00Z
date_updated: 2022-02-04T12:36:32Z
day: '07'
doi: 10.1016/S0022-5193(87)80100-5
extern: '1'
intvolume: ' 126'
issue: '1'
language:
- iso: eng
main_file_link:
- url: https://www.sciencedirect.com/science/article/pii/S0022519387801005?via%3Dihub
month: '05'
oa_version: None
page: 51 - 62
publication: Journal of Theoretical Biology
publication_identifier:
eissn:
- 1095-8541
issn:
- 0022-5193
publication_status: published
publisher: Elsevier
publist_id: '2727'
quality_controlled: '1'
scopus_import: '1'
status: public
title: The probability of peak shifts in a founder population
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 126
year: '1987'
...
---
_id: '3661'
abstract:
- lang: eng
text: We derive a formula giving thefrequency with which random drift shifts a population
betweenalternativeequilibria. This formula is valid when such shifts are rare
(Ns >> 1), and applies over a wide range of mutation rates. When the number
of mutations entering the population is low (4Nμ << 1), the rate of stochastic
shifts reduces to the product ofthe mutation rate and the probability of fixation
of a single mutation. However, when many mutations enter the population in each
generation (4Nμ >> 1), the rate is higher than would be expected if mutations
were established independently, and converges to that given by a gaussian approximation.
We apply recent results on bistable systems to extend this formula to the general
multidimensional case. This gives an explicit expression for thefrequencyof stochastic
shifts, which depends only on theequilibrium probability distribution near the
saddle point separating thealternative stable states. The plausibility of theories
of speciation through random drift are discussed in the light of these results.
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: Shahin
full_name: Rouhani, Shahin
last_name: Rouhani
citation:
ama: Barton NH, Rouhani S. The frequency of shifts between alternative equilibria.
Journal of Theoretical Biology. 1987;125(4):397-418. doi:10.1016/S0022-5193(87)80210-2
apa: Barton, N. H., & Rouhani, S. (1987). The frequency of shifts between alternative
equilibria. Journal of Theoretical Biology. Elsevier. https://doi.org/10.1016/S0022-5193(87)80210-2
chicago: Barton, Nicholas H, and Shahin Rouhani. “The Frequency of Shifts between
Alternative Equilibria.” Journal of Theoretical Biology. Elsevier, 1987.
https://doi.org/10.1016/S0022-5193(87)80210-2.
ieee: N. H. Barton and S. Rouhani, “The frequency of shifts between alternative
equilibria,” Journal of Theoretical Biology, vol. 125, no. 4. Elsevier,
pp. 397–418, 1987.
ista: Barton NH, Rouhani S. 1987. The frequency of shifts between alternative equilibria.
Journal of Theoretical Biology. 125(4), 397–418.
mla: Barton, Nicholas H., and Shahin Rouhani. “The Frequency of Shifts between Alternative
Equilibria.” Journal of Theoretical Biology, vol. 125, no. 4, Elsevier,
1987, pp. 397–418, doi:10.1016/S0022-5193(87)80210-2.
short: N.H. Barton, S. Rouhani, Journal of Theoretical Biology 125 (1987) 397–418.
date_created: 2018-12-11T12:04:29Z
date_published: 1987-04-21T00:00:00Z
date_updated: 2022-02-04T10:39:15Z
day: '21'
doi: 10.1016/S0022-5193(87)80210-2
extern: '1'
intvolume: ' 125'
issue: '4'
language:
- iso: eng
main_file_link:
- url: https://www.sciencedirect.com/science/article/pii/S0022519387802102?via%3Dihub
month: '04'
oa_version: None
page: 397 - 418
publication: Journal of Theoretical Biology
publication_identifier:
eissn:
- 1095-8541
issn:
- 0022-5193
publication_status: published
publisher: Elsevier
publist_id: '2722'
status: public
title: The frequency of shifts between alternative equilibria
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 125
year: '1987'
...
---
_id: '4323'
abstract:
- lang: eng
text: It is noted that the sibling competition model for the evolution of sex and
recombination, as it has been developed so far, involves truncation selection.
After briefly reviewing aspects of the development and behaviour of such models
an analytical treatment is presented which involves additive selection. Additive
selection, as compared with truncation selection, decreases the advantage of sex
to such an extent that it is unlikely that sibling competition could overcome
its intrinsic two-fold cost, although it could still be important in promoting
family variability produced by other mechanisms, such as polyandry.
acknowledgement: "We would like to thank M. Bulmer for his helpful comments. R. J.
Post was supported during this work by an MRC Postdoctoral Fellowship, and N. Barton
by an SRC Postdoctoral Fellowship. \r\n"
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: R.J.
full_name: Post, R.J.
last_name: Post
citation:
ama: Barton NH, Post RJ. Sibling competition and the advantage of mixed families.
Journal of Theoretical Biology. 1986;120(4):381-387. doi:10.1016/S0022-5193(86)80033-9
apa: Barton, N. H., & Post, R. J. (1986). Sibling competition and the advantage
of mixed families. Journal of Theoretical Biology. Elsevier. https://doi.org/10.1016/S0022-5193(86)80033-9
chicago: Barton, Nicholas H, and R.J. Post. “Sibling Competition and the Advantage
of Mixed Families.” Journal of Theoretical Biology. Elsevier, 1986. https://doi.org/10.1016/S0022-5193(86)80033-9.
ieee: N. H. Barton and R. J. Post, “Sibling competition and the advantage of mixed
families,” Journal of Theoretical Biology, vol. 120, no. 4. Elsevier, pp.
381–387, 1986.
ista: Barton NH, Post RJ. 1986. Sibling competition and the advantage of mixed families.
Journal of Theoretical Biology. 120(4), 381–387.
mla: Barton, Nicholas H., and R. J. Post. “Sibling Competition and the Advantage
of Mixed Families.” Journal of Theoretical Biology, vol. 120, no. 4, Elsevier,
1986, pp. 381–87, doi:10.1016/S0022-5193(86)80033-9.
short: N.H. Barton, R.J. Post, Journal of Theoretical Biology 120 (1986) 381–387.
date_created: 2018-12-11T12:08:15Z
date_published: 1986-06-21T00:00:00Z
date_updated: 2022-01-31T14:44:50Z
day: '21'
doi: 10.1016/S0022-5193(86)80033-9
extern: '1'
intvolume: ' 120'
issue: '4'
language:
- iso: eng
month: '06'
oa_version: None
page: 381 - 387
publication: Journal of Theoretical Biology
publication_identifier:
eissn:
- 1095-8541
issn:
- 0022-5193
publication_status: published
publisher: Elsevier
publist_id: '1720'
quality_controlled: '1'
status: public
title: Sibling competition and the advantage of mixed families
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 120
year: '1986'
...