scholarly journals Real royal road functions for constant population size

2004 ◽  
Vol 320 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Tobias Storch ◽  
Ingo Wegener
Keyword(s):  
Population Size ◽  
Constant Population Size ◽  
Royal Road

scholarly journals Inferences About Human Demography Based on Multilocus Analyses of Noncoding Sequences

Genetics ◽  
2002 ◽  
Vol 161 (3) ◽  
pp. 1209-1218 ◽  
Author(s):  
Anna Pluzhnikov ◽  
Anna Di Rienzo ◽  
Richard R Hudson
Keyword(s):  
Population Size ◽  
Italian Population ◽  
Chinese Sample ◽  
Constant Population Size ◽  
Human Demography ◽  
Multilocus Analysis ◽  
Simple Expansion ◽  
Size Model ◽  
Expansion Model ◽  
Tajima’S D

Abstract Data from 10 unlinked autosomal noncoding regions, resequenced in 15 individuals from each of three populations, were used in a multilocus analysis to test models of human demography. Each of the 10 regions consisted of ~2500 bp. The multilocus analysis, based on summary statistics (average and variance of Tajima's D and Fu and Li's D*), was used to test a family of models with recent population expansion. The African sample (Hausa of Cameroon) is compatible with a constant population size model and a range of models with recent expansion. For this population sample, we estimated confidence sets that showed the limited range of parameter values compatible with growth. For an exponential growth rate as low as 1 × 10−3/generation, population growth is unlikely to have started prior to 50,000 years ago. For higher growth rates, the onset of growth must be more recent. On the basis of the average value of Tajima's D, our sample from an Italian population was found to be incompatible with a constant population size model or any simple expansion model. In the Chinese sample, the variance of Tajima's D was too large to be compatible with the constant population size model or any simple expansion model.

Heterogeneity of Microsatellite Mutations Within and Between Loci, and Implications for Human Demographic Histories

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1269-1284 ◽  
Author(s):  
Anna Di Rienzo ◽  
Peter Donnelly ◽  
Chris Toomajian ◽  
Bronwyn Sisk ◽  
Adrian Hill ◽  
...  
Keyword(s):  
Population Size ◽  
Cancer Patients ◽  
Somatic Mutations ◽  
Repeat Unit ◽  
Population Expansion ◽  
Population Variation ◽  
Rapid Expansion ◽  
Constant Population Size ◽  
Time Estimates ◽  
Novel Approach

Abstract Microsatellites have been widely used to reconstruct human evolution. However, the efficient use of these markers relies on information regarding the process producing the observed variation. Here, we present a novel approach to the locus-by-locus characterization of this process. By analyzing somatic mutations in cancer patients, we estimated the distributions of mutation size for each of 20 loci. The same loci were then typed in three ethnically diverse population samples. The generalized stepwise mutation model was used to test the predicted relationship between population and mutation parameters under two demographic scenarios: constant population size and rapid expansion. The agreement between the observed and expected relationship between population and mutation parameters, even when the latter are estimated in cancer patients, confirms that somatic mutations may be useful for investigating the process underlying population variation. Estimated distributions of mutation size differ substantially amongst loci, and mutations of more than one repeat unit are common. A new statistic, the normalized population variance, is introduced for multilocus estimation of demographic parameters, and for testing demographic scenarios. The observed population variation is not consistent with a constant population size. Time estimates of the putative population expansion are in agreement with those obtained by other methods.

When Did the Human Population Size Start Increasing?

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1865-1874 ◽  
Author(s):  
Jeffrey D Wall ◽  
Molly Przeworski
Keyword(s):  
Population Size ◽  
Growth Parameters ◽  
Balancing Selection ◽  
Upper Paleolithic ◽  
Population Subdivision ◽  
Data Sets ◽  
Demographic Model ◽  
Frequency Spectra ◽  
Constant Population Size

Abstract We analyze the frequency spectra of all available human nuclear sequence data sets by using a model of constant population size followed by exponential growth. Parameters of growth (more extreme than or) comparable to what has been suggested from mtDNA data can be rejected for 6 out of the 10 largest data sets. When the data are separated into African and non-African samples, a constant size no-growth model can be rejected for 4 out of 8 non-African samples. Long-term growth (i.e., starting 50–100 kya) can be rejected for 2 out of 8 African samples and 5 out of 8 non-African ones. Under more complex demographic models, including a bottleneck or population subdivision, more of the data are compatible with long-term growth. One problem with the data used here is that a subset of loci may reflect the action of natural selection as well as of demography. It remains possible that the correct demographic model is one of constant population size followed by long-term growth but that at several loci the demographic signature has been obscured by balancing or diversifying selection. However, it is not clear that the data at these loci are consistent with a simple model of balancing selection; more complicated selective alternatives cannot be tested unless they are made explicit. An alternative explanation is that population size growth is more recent (e.g., upper Paleolithic) and that some of the loci have experienced recent directional selection. Given the available data, the latter hypothesis seems more likely.

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