+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Eco-evolutionary dynamics: fluctuations in population growth rate reduce effective population size in chinook salmon



Eco-evolutionary dynamics: fluctuations in population growth rate reduce effective population size in chinook salmon



Ecology 91(3): 902-914



We empirically assess the relationship between population growth rate ( lambda , a parameter central to ecology) and effective population size (Ne, a key parameter in evolutionary biology). Recent theoretical and numerical studies indicate that in semelparous species with variable age at maturity (such as Pacific salmon, many monocarpic plants, and various other species), differences in mean reproductive success among individuals reproducing in different years leads to variation in lambda , and this in turn can reduce Ne. However, this phenomenon has received little empirical evaluation. We examined time series of abundance data for 56 populations of chinook salmon (Onchorhynchus tshawytscha) from the northwestern United States and compared Ne (calculated from demographic data) with the total number of spawners each generation (NT). Important results include: (1) The mean multigenerational ratio ( overhead single bar N/( overhead single bar NT was 0.64 (median = 0.67), indicating that annual variation in lambda reduces effective population size in chinook salmon by an average of appr. 35%. These reductions are independent of, and in addition to, factors that reduce Ne within individual cohorts (uneven sex ratio and greater-than-random variance in reproductive success). (2) The coefficient of variation of lambda was the most important factor associated with reductions in Ne, explaining up to two-thirds of the variance in ( overhead single bar Ne/ overhead single bar NT. (3) Within individual generations, Ne was lower when there was a negative correlation between annual Ni and lambda i.e., when relatively few breeders produced relatively high numbers of offspring. Our results thus highlight an important and little-studied eco-evolutionary trade-off: density-dependent compensation has generally favorable ecological consequences (promoting stability and long-term viability) but incurs an evolutionary cost (reducing Ne because a few individuals make a disproportionate genetic contribution). (4) For chinook salmon, overhead hat NeH (an estimator based on the harmonic mean number of breeders per year) is generally a good proxy for true Ne and requires much less data to calculate.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 037414279

Download citation: RISBibTeXText

PMID: 20426347

DOI: 10.1890/09-0366.1


Related references

Effective population size in winter-run chinook salmon. Conservation Biology 8(3): 890-892, 1994

Effective population size in winter-run chinook salmon. Conservation Biology. 9(3): 615-624, 1995

The impact of supplementation in winter-run chinook salmon on effective population size. Journal of Heredity 91(2): 112-116, 2000

Effective population size of winter-run chinook salmon based on microsatellite analysis of returning spawners. Canadian Journal of Fisheries and Aquatic Sciences 57(12): 2368-2373, 2000

Census vs. effective population size in chinook salmon: large- and small-scale environmental perturbation effects. Molecular Ecology 12(10): 2571-2583, 2003

Evolutionary dynamics of a polymorphic self-replicator population with a finite population size and hyper mutation rate. Journal of Theoretical Biology 382: 298-308, 2015

Effective population size and evolutionary dynamics in outbred laboratory populations ofDrosophila. Journal of Genetics 92(3): 349-361, 2013

Effective population size and evolutionary dynamics in outbred laboratory populations of Drosophila. Journal of Genetics 92(3): 349-361, 2013

Conservation genetics of pacific salmon ii. effective population size and the rate of loss of genetic variability. Journal of Heredity 81(4): 267-276, 1990

Reduced genetic diversity and effective population size in an endangered Atlantic salmon (Salmo salar) population from Maine, USA. Conservation Genetics 7(1): 91-104, 2006

Growth rate population entropy and evolutionary dynamics. Theoretical Population Biology 41(2): 208-236, 1992

Eco-Evolutionary Dynamics || Eco-Evolutionary Dynamics: Disentangling Phenotypic, Environmental and Population Fluctuations. Philosophical Transactions Biological Sciences 364(1523): 1491-1498, 2009

Effects of Ceratomyxosis on Population Dynamics of Klamath Fall-Run Chinook Salmon. Transactions of the American Fisheries Society 140(5): 1380-1391, 2011

Studies on mosquito population dynamics in Cholla-bugdo, Korea (1985-1990). 1. Seasonal and annual fluctuations in population size. Korean Journal of Entomology 214: 141-155, 1991

Studies on mosquito population dynamics in cholla bugdo korea 1985 1990 i. seasonal and annual fluctuations in population size. Korean Journal of Entomology 21(4): 141-155, 1991