Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Bottleneck effect on evolutionary rate in the nearly neutral mutation model

H Araki1, H Tachida

  • 1Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.

Genetics
|October 23, 1997
PubMed
Summary

Changing population sizes can cause overdispersion of the molecular clock, where evolutionary rates vary more than expected. This occurs under the nearly neutral mutation model when population size fluctuates cyclically.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Changes in the plasma diazepam concentration and its anticonvulsant effect after the discharge of a diazepam suppository from the rectum in rats.

Methods and findings in experimental and clinical pharmacology·2007
Same author

Continuous infusion of 5-fluorouracil with versus without low-dose, consecutive administration of cisplatin in advanced colorectal cancer. A prospective randomized phase II study.

Journal of experimental & clinical cancer research : CR·2007
Same author

Genetic coadaptation of the amylase gene system in Drosophila melanogaster: evidence for the selective advantage of the lowest AMY activity and of its epistatic genetic background.

The Journal of heredity·2005
Same author

Charcot-Marie-Tooth families in Japan with MPZ Thr124Met mutation.

Journal of neurology, neurosurgery, and psychiatry·2004
Same author

Serotonin 2C receptor gene Cys23Ser polymorphism: a candidate genetic risk factor of migraine with aura in Japanese population.

Acta neurologica Scandinavica·2004
Same author

The microbial synergy of Peptostreptococcus micros and Prevotella intermedia in a murine abscess model.

Oral microbiology and immunology·2004

Area of Science:

  • Evolutionary Biology
  • Molecular Evolution
  • Population Genetics

Background:

  • Evolutionary rates among lineages can exhibit greater variance than predicted by simple Poisson processes, a phenomenon termed overdispersion of the molecular clock.
  • Under the nearly neutral mutation model, overdispersion is typically observed within a restricted range of population size (N) and selection coefficient standard deviation (sigma).

Purpose of the Study:

  • To investigate the impact of fluctuating population sizes on evolutionary rates.
  • To determine if cyclic population size changes can explain the overdispersion of the molecular clock within the nearly neutral mutation model.

Main Methods:

  • Computer simulations were employed to model evolutionary rates.
  • The nearly neutral mutation model was assumed, with population size (N) cyclically varying between two values (N1 and N2, where N1 > N2).

Related Experiment Videos

Main Results:

  • Overdispersion was observed when the reduced population size (bottleneck state) persisted for a duration exceeding approximately 0.1/u generations (where u is the mutation rate) and 2N2 sigma was less than two.
  • The primary driver of overdispersion is the stochastic reduction in average population fitness during bottlenecks, leading to subsequent advantageous substitutions primarily in those affected populations upon size expansion.
  • The acceleration of evolutionary rates post-bottleneck was not uniform across all genetic loci due to the stochastic nature of fitness reduction.

Conclusions:

  • Cyclic population size changes, particularly prolonged bottlenecks, can induce overdispersion of the molecular clock.
  • The nearly neutral mutation model, incorporating fluctuating population sizes, provides a plausible mechanism for explaining the observed overdispersion of molecular clocks in evolutionary studies.