Hans Siegismund - Academia.edu (original) (raw)

Papers by Hans Siegismund

Science, 2016

Our closest living relatives, chimpanzees and bonobos, have a complex demographic history. We ana... more Our closest living relatives, chimpanzees and bonobos, have a complex demographic history. We analyzed the high-coverage whole genomes of 75 wild-born chimpanzees and bonobos from 10 countries in Africa. We found that chimpanzee population substructure makes genetic information a good predictor of geographic origin at country and regional scales. Multiple lines of evidence suggest that gene flow occurred from bonobos into the ancestors of central and eastern chimpanzees between 200,000 and 550,000 years ago, probably with subsequent spread into Nigeria-Cameroon chimpanzees. Together with another, possibly more recent contact (after 200,000 years ago), bonobos contributed less than 1% to the central chimpanzee genomes. Admixture thus appears to have been widespread during hominid evolution.

South African Journal of Science, Dec 1, 2008

CITATIONS 7 READS 25 14 authors, including: Some of the authors of this publication are also work... more CITATIONS 7 READS 25 14 authors, including: Some of the authors of this publication are also working on these related projects: Large whale research in South Africa: genetic relatedness, stock identification, abundance, feeding and migratory behaviours View project Tropical biodiversity research and development View project

Evol Ecol, 2007

A previous study showed that some individuals of the tetraploid Galápagos endemic Scalesia affini... more A previous study showed that some individuals of the tetraploid Galápagos endemic Scalesia affinis were able to produce offspring after selfing. The present study compares the fitness of self-pollinated offspring with the fitness of cross-pollinated offspring. Germination success, seedling survival, and four different growth parameters was measured. In most of the studied characters selfed offspring were significantly inferior to outcrossed progeny. The effect was very clear in germination and survival. Outcrossed embryos were 3.4 times more likely to germinate than those that were selfed-fertilized, and the mortality was 84% higher among selfed individuals. Also, there was no genetic variation in inbreeding depression. The present study is based on material from a large population on Isabela Island, Galápagos. At other localities in the archipelago, populations have been through recent dramatic bottlenecks due to the grazing of introduced mammals. Considering the significant inbreeding depression found in the large population and the presence of a partial self-incompatibility system, these small populations are likely to be highly vulnerable and their future survival critically threatened.

Hereditas, 1985

1985. Genetic studies of Gammarus. 111. Inheritance of electrophoretic variants of the enzymes ma... more 1985. Genetic studies of Gammarus. 111. Inheritance of electrophoretic variants of the enzymes mannose phosphate isomerase and glucose phosphate isomerase in Gammarus oceanicus. -Heredifas 102: 25-31. Lund. Sweden. ISSN 0018-0661.

The Journal of Heredity, 1992

... Table 2. Chi-square tests for linkage and recombination values for pearl millet mutants ... {... more ... Table 2. Chi-square tests for linkage and recombination values for pearl millet mutants ... {J. i. = J. ischiosetosa, J. a. = J. albifrons, J. p. = J. praehirsuta) and the total number of females Males Location Niva Borup Sand Vilsund Lagstor Tars Vellerup Bandholm ...

Bmc Veterinary Research, Feb 3, 2015

Background: Understanding the epidemiology of foot-and-mouth disease (FMD), including roles playe... more Background: Understanding the epidemiology of foot-and-mouth disease (FMD), including roles played by different hosts, is essential for improving disease control. The African buffalo (Syncerus caffer) is a reservoir for the SAT serotypes of FMD virus (FMDV). Large buffalo populations commonly intermingle with livestock in Kenya, yet earlier studies have focused on FMD in the domestic livestock, hence the contribution of buffalo to disease in livestock is largely unknown. This study analysed 47 epithelia collected from FMD outbreaks in Kenyan cattle between 2008 and 2012, and 102 probang and serum samples collected from buffalo in three different Kenyan ecosystems; Maasai-Mara (MME) (n = 40), Tsavo (TSE) (n = 33), and Meru (ME) (n = 29). Results: Antibodies against FMDV non-structural proteins were found in 65 of 102 (64%) sera from buffalo with 44/102 and 53/102 also having neutralising antibodies directed against FMDV SAT 1 and SAT 2, respectively. FMDV RNA was detected in 42% of the buffalo probang samples by RT-qPCR (Cycle Threshold (Ct) ≤32). Two buffalo probang samples were positive by VI and were identified as FMDV SAT 1 and SAT 2 by Ag-ELISA, while the latter assay detected serotypes O (1), A (20), SAT 1 (7) and SAT 2 (19) in the 47 cattle epithelia. VP1 coding sequences were generated for two buffalo and 21 cattle samples. Phylogenetic analyses revealed SAT 1 and SAT 2 virus lineages within buffalo that were distinct from those detected in cattle.

Scandinavian Journal of Forest Research, 2003

An unmanaged stand of Quercus petraea (Matt.) Liebl. in Denmark was studied for morphological and... more An unmanaged stand of Quercus petraea (Matt.) Liebl. in Denmark was studied for morphological and microsatellite variation. The sample of 339 trees, which is part of a European network of similar oak stands, revealed a unimodal (single) distribution of Q. petraea but found evidence for extreme morphological variation expressed by a number of trees. While hybridization with Quercus robur may be one reason for such a pattern of variation, other possibilities exist. Variation at six microsatellite loci indicated no correlation with any of the nine morphological traits investigated, and showed only small deviations from Hardy Á/Weinberg proportions. The levels of observed heterozygosity and allelic diversity were similar to those found within other stands of Q. petraea in central Europe, and no reduction in diversity was evident for the Danish stand despite its being situated at the margin of the distribution of the species. Weak, but significant, spatial genetic structure was identified using Moran's index, but the level of spatial autocorrelation was found to be dependent on locus, allele frequency and sample size, which should be greater than 100 trees to identify spatial patterns. Spatial genetic structure was found to be higher for trees with a diameter at breast height (dbh) of B/40 cm than for larger trees (/40 cm dbh) and this is thought to reflect a balance between the influence of limited seed dispersal, which will act to establish genetic structure in younger generations, and selection, which will disrupt genetic structure in older generations. The life history of the stand is discussed in relation to the observed genetic parameters.

The Journal of Heredity, 1995

The structure of elephant populations from east and south Africa has been analyzed by Georgiadis ... more The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion that there was a significant differentiation at the continental level, but that "populations were not significantly subdivided at the regional levels." The data were reanalyzed by Monte-Carlo permutation tests where population subdivision was tested by using F statistics based on partitioning the total haplotype diversity among populations. This resulted in identical conclusions at the continental level, but revealed in addition a significant subdivision at the regional level indicating haplotype frequency differences among the populations.

Http Dx Doi Org 10 1080 02827589709355394, Dec 10, 2008

... Naturskove i Danmark—en foreløbig opgørelse over danske naturskove udenfor statsskovene. Inte... more ... Naturskove i Danmark—en foreløbig opgørelse over danske naturskove udenfor statsskovene. Intern DGU-rapport. Miljøministeriet, Skov-og Natur-styrelsen. Palmer, JD 1987. Chloroplast evolution and biosystematic uses of chloroplast DNA variation. Am. Nat. 130: 6-29. ...

Evolutionary Ecology, 2002

The presence of neuter ray florets in species within Asteraceae is generally believed to increase... more The presence of neuter ray florets in species within Asteraceae is generally believed to increase pollinator attraction. In the endemic Gala´pagos genus Scalesia (Asteraceae) a natural variation in the presence/absence of neuter ray florets is found. To evaluate whether the presence of ray florets plays a selective role on female reproductive success we chose two species of Scalesia, Scalesia affinis that carries ray florets and S. pedunculata that is rayless. On Santa Cruz Island capitula of S. pedunculata were equipped with fake ray florets while others were untouched. On Isabela Island ray florets were removed on half of the capitula of S. affinis. In S. affinis rayed capitula received more pollinators and more pollen, which resulted in a significantly higher embryo production. In S. pedunculata no effect on embryo production was found. The disagreement between the two species may correspond to a difference in visitation frequency, S. pedunculata receiving many more visit than S. affinis. Thus, ray floret development proved beneficial in pollinator-restricted localities.

Heredity, 1996

Mitochondrial DNA (mtDNA) control region sequences from six Kenyan Grant's gazelle (Gazella grant... more Mitochondrial DNA (mtDNA) control region sequences from six Kenyan Grant's gazelle (Gazella granti) populations were highly divergent among locations. Neighbouring populations not separated by geographical or vegetational barriers exhibited a nucleotide sequence divergence of about 14 per cent. A similar level of divergence separates Grant's gazelles from a closely related species, the Soemmering's gazelle (G. soemmeringii). Nuclear microsatellite repeat number variation at two loci also indicated substantial population genetic differentiation. Despite high levels of sequence divergence, populations of Grant's gazelles were more closely related to each other than to Soemmering's and Thomson's gazelles (G. thomsoni) as measured by nucleotide sequence divergence at the mtDNA protein coding cytochrome b gene and the nuclear o-lactalbumin gene. This pattern of extensive differentiation is hypothesized to have resulted from recently established contacts between formerly allopatric populations.

Conserv Genet, 2008

Page 1. RESEARCH ARTICLE Three reciprocally monophyletic mtDNA lineages elucidate the taxonomic s... more Page 1. RESEARCH ARTICLE Three reciprocally monophyletic mtDNA lineages elucidate the taxonomic status of Grant's gazelles Eline D. Lorenzen Æ Peter Arctander Æ Hans R. Siegismund Received: 21 March 2007 / Accepted ...

Infection Genetics and Evolution, 2010

Proceedings of the Royal Society B Biological Sciences, 2009

J Hered, 2005

We obtained fresh dung samples from 202 (133 mother-offspring pairs) savannah elephants (Loxodont... more We obtained fresh dung samples from 202 (133 mother-offspring pairs) savannah elephants (Loxodonta africana) in Samburu, Kenya, and genotyped them at 20 microsatellite loci to assess genotyping success and errors. A total of 98.6% consensus genotypes was successfully obtained, with allelic dropout and false allele rates at 1.6% (n 5 46) and 0.9% (n 5 37) of heterozygous and total consensus genotypes, respectively, and an overall genotyping error rate of 2.5% based on repeat typing. Mendelian analysis revealed consistent inheritance in all but 38 allelic pairs from mother-offspring, giving an average mismatch error rate of 2.06%, a possible result of null alleles, mutations, genotyping errors, or inaccuracy in maternity assignment. We detected no evidence for large allele dropout, stuttering, or scoring error in the dataset and significant Hardy-Weinberg deviations at only two loci due to heterozygosity deficiency. Across loci, null allele frequencies were low (range: 0.000-0.042) and below the 0.20 threshold that would significantly bias individual-based studies. The high genotyping success and low errors observed in this study demonstrate reliability of the method employed and underscore the application of simple pedigrees in noninvasive studies. Since none of the sires were included in this study, the error rates presented are just estimates.