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94
Inferences from DNA data: population histories, evolutionary processes, and forensic match probabilities.
- Journal of Royal Statistics Society, Series A
, 2003
"... We develop a flexible class of... ..."
True and false gharials: A nuclear gene phylogeny of Crocodylia
- Syst. Biol
, 2003
"... Abstract. • The phylogeny of Crocodylia offers an unusual twist on the usual molecules versus morphology story. The true gharial (Gavialis gangeticus) and the false gharial (Tomistoma schlegelii), as their common names imply, have appeared in all cladistic morphological analyses as distantly related ..."
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Cited by 18 (2 self)
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Abstract. • The phylogeny of Crocodylia offers an unusual twist on the usual molecules versus morphology story. The true gharial (Gavialis gangeticus) and the false gharial (Tomistoma schlegelii), as their common names imply, have appeared in all cladistic morphological analyses as distantly related species, convergent upon a similar morphology. In contrast, all previous molecular studies have shown them to be sister taxa. We present the first phylogenetic study of Crocodylia using a nuclear gene. We cloned and sequenced the c-myc proto-oncogene from Alligator mississippiensis to facilitate primer design and then sequenced an 1,100-base pair fragment that includes both coding and noncoding regions and informative indels for one species in each extant crocodylian genus and six avian outgroups. Phylogenetic analyses using parsimony, maximum likelihood, and Bayesian inference all strongly agreed on the same tree, which is identical to the tree found in previous molecular analyses: Gavialis and Tomistoma are sister taxa and together are the sister group of Crocodylidae. Kishino-Hasegawa tests rejected the morphological tree in favor of the molecular tree. We excluded long-branch attraction and variation in base composition among taxa as explanations for this topology. To explore the causes of discrepancy between molecular and morphological estimates of crocodylian phylogeny, we examined puzzling features of the morphological data
The consequences of phenotypic plasticity for ecological speciation
, 2011
"... We use an individual-based numerical simulation to study the effects of phenotypic plasticity on ecological speciation. We find that adaptive plasticity evolves readily in the presence of dispersal between populations from different ecological environments. This plasticity promotes the colonizatio ..."
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Cited by 17 (5 self)
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We use an individual-based numerical simulation to study the effects of phenotypic plasticity on ecological speciation. We find that adaptive plasticity evolves readily in the presence of dispersal between populations from different ecological environments. This plasticity promotes the colonization of new environments but reduces genetic divergence between them. We also find that the evolution of plasticity can either enhance or degrade the potential for divergent selection to form reproductive barriers. Of particular importance here is the timing of plasticity in relation to the timing of dispersal. If plasticity is expressed after dispersal, reproductive barriers are generally weaker because plasticity allows migrants to be better suited for their new environment. If plasticity is expressed before dispersal, reproductive barriers are either unaffected or enhanced. Among the potential reproductive barriers we considered, natural selection against migrants was the most important, primarily because it was the earliest-acting barrier. Accordingly, plasticity had a much greater effect on natural selection against migrants than on sexual selection against migrants or on natural and sexual selection against hybrids. In general, phenotypic plasticity can strongly alter the process of ecological speciation and should be considered when studying the evolution of reproductive barriers.
Estimating Y chromosome specific microsatellite mutation frequencies using deep rooting pedigrees
, 1997
"... Recently, a set of highly polymorphic chromosome Y specific microsatellites became available for forensic, population genetic and evolutionary studies. However, the lack of a mutation frequency estimate for these loci prevents a reliable application. We therefore used seven chromosome Y tetranucleot ..."
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Recently, a set of highly polymorphic chromosome Y specific microsatellites became available for forensic, population genetic and evolutionary studies. However, the lack of a mutation frequency estimate for these loci prevents a reliable application. We therefore used seven chromosome Y tetranucleotide repeat loci to screen 42 males who are descendants from 12 ‘founding fathers’ by a total number of 213 generations. As a result, we were able to estimate an average chromosome Y tetranucleotide mutation frequency of 0.20 % (95 % CIL 0.05–0.55). This closely matches the often cited Weber and Wong estimate of 0.21 % for a set of autosomal tetranucleotide repeats. Expanding the set of microsatellites with two more loci (a tri- and a penta-nucleotide repeat locus) an average chromosome Y microsatellite mutation frequency of 0.21 % (95 % CIL 0.06–0.49) was found. These estimates suggest that microsatellites on the Y chromosome have mutation frequencies comparable to those on the autosomes. This supports the hypothesis that slippage-generated growth is the driving force behind the microsatellite variability.
Recurrent duplication and deletion polymorphisms on the long arm of the Y chromosome in normal
, 1996
"... Deletion of the 50f2/C (DYS7C) locus in interval 6 of Yq has previously been reported as a polymorphism in three males. We describe a survey of worldwide populations for further instances of this deletion. Of 859 males tested, 55 (∼6%) show absence of the 50f2/C locus; duplication of the locus was a ..."
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Cited by 14 (2 self)
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Deletion of the 50f2/C (DYS7C) locus in interval 6 of Yq has previously been reported as a polymorphism in three males. We describe a survey of worldwide populations for further instances of this deletion. Of 859 males tested, 55 (∼6%) show absence of the 50f2/C locus; duplication of the locus was also detected in eight out of 595 males (∼1.4%). Populations having the deletion are confined to Asia, Australasia, and southern and northern Europe; of those of reasonable sample size, Finns had the highest deletion frequency (55%; n = 21). The deletions vary in size and the larger ones remove some of the RBM (RNA Binding Motif) genes, but none of the deletion males lack DAZ (Deleted in AZoospermia), a candidate gene for the azoospermia factor. On a tree of Y haplotypes, 28 deletion and eight
Models of microsatellite evolution
- Statistical Methods in Molecular Evolution, Series: Statistics for Biology and Health
, 2004
"... Microsatellites are simple sequence repeats in DNA, for example the motif AT repeated twenty-five times in a row. Microsatellites mutate by changing the number of their repeats, for example the (AT)25 mentioned in the previous sentence might become an (AT)24 or (AT)26 in that individual’s offspring. ..."
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Cited by 10 (2 self)
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Microsatellites are simple sequence repeats in DNA, for example the motif AT repeated twenty-five times in a row. Microsatellites mutate by changing the number of their repeats, for example the (AT)25 mentioned in the previous sentence might become an (AT)24 or (AT)26 in that individual’s offspring.
Leishmania and the Leishmaniases: a parasite genetic update and advances in taxonomy, epidemiology and pathogenicity
- in humans,” Advances in Parasitology
, 2007
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Statistics for microsatellite variation based on coalescence
, 1996
"... The stepwise mutation model, which was at one time chiefly of interest in studying the evolution of protein charge-states, has recently undergone a resurgence of interest with the new popularity of microsatellites as phylogenetic markers. In this paper we describe a method which makes it possible to ..."
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Cited by 7 (2 self)
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The stepwise mutation model, which was at one time chiefly of interest in studying the evolution of protein charge-states, has recently undergone a resurgence of interest with the new popularity of microsatellites as phylogenetic markers. In this paper we describe a method which makes it possible to transfer many population genetics results from the standard infinite sites model to the stepwise mutation model. We study in detail the properties of pairwise differences in microsatellite repeat number between randomly chosen alleles. We show that the problem of finding the expected squared distance between two individuals and finding the variance of the squared distance can be reduced for a wide range of population models to finding the mean and mean square coalescence times. In many cases the distributions of coalescence times have already been studied for infinite site problems. In this study we show how to calculate these quantities for several population models. We also calculate the variance in mean squared pairwise distance (an estimator of mutation rate _ population size) for samples of arbitrary size and show that this variance does not approach zero as the sample size increases. We can also use our method to study alleles at linked microsatellite loci. We suggest a metric which quantifies the level of association between loci effectively a measure of linkage disequilibrium. It is shown that there can be linkage disequilibrium between partially linked loci at mutation drift equilibrium. 1996 Academic Press, Inc.
Genetic variation at twenty-three microsatellite loci in sixteen human populations
- J. Genet
, 1999
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Analysis of polymorphic microsatellite markers for typing Penicillium marneffei isolates
- J. Clin. Microbiol
, 2004
"... These include: This article cites 50 articles, 28 of which can be accessed free at: ..."
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Cited by 7 (2 self)
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These include: This article cites 50 articles, 28 of which can be accessed free at:
