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Avian introgression in the genomic era

Avian Research 2017年第4期8卷 181-191页

作者： Jente Ottenburghs Robert H.S.Kraus Pim van Hooft sipke e.van wieren Ronald C.Ydenberg Herbert H.T.Prins Resource ecology Group Wageningen UniversityDroevendaalsesteeg 3a6708 PB WageningenThe Netherlands Department of Biology University of Konstanz78457 ConstanceGermany Department of Migration and Immuno-ecology Max Planck Institute for OrnithologyAm Obstberg 178315 RadolfzellGermany Centre of Wildlife ecology Simon Fraser UniversityBurnabyBC V5A 1S6Canada

Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into the speciation process.In the last decade,the toolkit for studying introgression has expanded together with the development of molecular markers.In this review,we explore how genomic data,the most recent step in this methodological progress,impacts different aspects in the study of avian introgression.First,the detection of hybrids and backcrosses has improved dramatically.The most widely used software package is STRUCTURe.Phylogenetic discordance(i.***.different loci resulting in discordant gene trees) is another means for the detection of introgression,although it should be regarded as a starting point for further analyses,not as a definitive proof of introgression.Specifically,disentangling introgression from other biological processes,such as incomplete lineage sorting,remains a challenging endeavour,although new techniques,such as the D-statistic,are being developed.In addition,phylogenetics might require a shift from trees to networks.Second,the study of hybrid zones by means of geographical or genomic cline analysis has led to important insights into the complex interplay between hybridization and speciation.However,because each hybrid zone study is just a single snapshot of a complex and continuously changing interaction,hybrid zones should be studied across different temporal and/or spatial scales.A third powerful tool is the genome scan.The debate on which evolutionary processes underlie the genomic landscape is still ongoing,as is the question whether loci involved in reproductive isolation cluster together in ‘islands of speciation' or whether they are scattered throughout the genome.exploring genomic landscapes across the avian tree of life will be an exciting field for further research.Finally,the findings from these different methods should be incorporated into specific speciation scena

关键词： Admixture Cline theory D-statictic Genomic landscape Hybridization Phylogenetic discordance

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Seasonal resource use and niche breadth in an assemblage of coexisting grazers in a fenced Park

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Open Journal of ecology 2013年第6期3卷 383-388页

作者： Shem M.Mwasi sipke e.van wieren Ignas M.A.Heitkonig Herbert H.T.Prins School for Field Studies Center for Wildlife Management StudiesNairobiKenya Resource ecology Group Wageningen UniversityWageningenThe Netherlands

Many small Parks inKenyaare being fenced to control human-wildlife conflict. Some of these Parks have a diversity of large herbivores which might increase in density in the wake of fencing and subsequent compression of their home ranges due to closure of their migratory routes. It is important to understand the consequences of such an increase on the structuring of insularised herbivore assemblages in such Parks. We studied seasonal resource segregation and niche breadth variation as mechanisms of coexistence in a high density grazer assemblage inLakeNakuruNational Parkwhich is small and completely fenced. Diet composition and habitat use were considered as variables of resource use. We predicted that overlap in resource use and niche breadth would be the smallest among grazers with similar body weights in the dry season which is the most resource limiting for grazers in east Africa. Our results were contrary to the predictions because of lack of seasonal differentiation in the overlap of diet composition and habitat use, and in niche breadth. Overlaps in resource use were consistently high during both the wet and dry seasons, and niche breadth contraction during the dry season was not possible probably because of lack of species-specific niches during the dry season. Our results suggest that there might be competitive interactions in this grazer assemblage which is an important parameter to consider in the management of the Park.

关键词： Niche Breadth Diet Composition Coexistence Habitat Use Overlap Season Grazer Competitive Interactions

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Distributional congruence of mammalian herbivores in the Trans-Himalayan Mountains

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Current Zoology 2013年第1期59卷 116-124页

作者： Tsewang NAMGAIL sipke e. van wieren Herbert H.T. PRINS Resource ecology Group Wageningen University Droevendaalsesteeg 3a 6708 PB Wageningen The Netherlands U.S. Geological Survey Las Vegas Field Station 160 N Stephanie Street Henderson 89074 NV USA

Large-scale distribution and diversity patterns of mammalian herbivores, especially less charismatic species in alpine environments remain little understood. We studied distributional congruence of mammalian herbivores in the Trans-Himalayan region of Ladakh to see if the distributions of less prominent and smaller herbivores can be determined from those of larger and more prominent herbivores like ungulates. Using a similarity index, we assessed shared distributions of species in 20×20 km2grid-cells in an area of about 80,000 km2. We used the Unweighted Pair-Group Method with Arithmetic Average (UPGMA) to classify mammalian herbivores into groups with similar distributions. We then used the G-test of independence to look for statistical significance of the groups obtained. We identified six groups of mammalian herbivores with distributions more similar than expected at random. The largest group was composed of nine species whereas the other large group comprised six species. Canonical Correspondence Analysis (CCA), used to relate the groups with environmental features, showed that the largest group occurred in higher and flatter areas, while the other large group occurred in lower and steeper areas. Large herbivores like ungulates can be used as surrogate for less prominent small herbivores while identifying areas for latter’s protection in the inaccessible mountainous regions of the Trans-Himalaya.

关键词：植食性哺乳动物喜马拉雅山脉一致性有蹄类动物食草动物喜马拉雅地区加权算术平均典范对应分析

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existing theories do not explain sex ratio variation at birth in monomorphic roe deer (Capreolus capreolus)

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Integrative Zoology 2007年第1期2卷 10-18页

作者： Stefan Jacob VReUGDeNHIL Leo van BReUKeLeN sipke egbert van wieren Waternet Research and DevelopmentVogelenzangThe Netherlands Resource ecology Group Wageningen UniversityWageningenThe Netherlands Ministry of Agriculture Nature and Food QualityDienst Landelijk GebiedUtrechtThe Netherlands

The phenomenon of skewed sex ratios at birth has been reported in many ungulate species.So far,no consistent trend has emerged for roe deer(Capreolus capreolus),because male-biased,female-biased and equal sex ratios at birth have all been found.Nevertheless,both the Trivers–Willard hypothesis and the theory of local resource competition have gained support.Despite the great number of studies carried out regarding the ecology of roe deer,too many aspects remain unclear,and contradictory results have been produced with respect to several crucial elements.Without further research,the discussion on which theory applies will therefore remain inconclusive.We put forward the argument that eventually the theories of Trivers–Willard and local resource competition can be considered as being not essentially different.After all,both theories explain the observed skewed sex ratios as being due to the effect of the progeny s sex on the mother s body condition and hence her reproductive success in subsequent years.Furthermore,neither theory is likely to prove to be suitable for roe deer,as several assumptions are unlikely to be met.In roe deer,skewed ratios probably only have a temporal character.As a matter of fact,several observations of skewed sex ratios in birds and mammals did not withstand the accumulation of further data,as sex ratios that were initially believed to be biased turned out to be equal in the long term.This is likely to be the case in roe deer as well.We hypothesize that roe deer,as r-strategists,will produce as many offspring as possible,regardless of sex.

关键词： roe deer sex ratio theory.

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