The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubesce... more The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubescens and A. r. alticola in North America and A. [r.] japonicus in northeast Asia. Despite their great morphological resemblance in breeding plumage, most individuals can be assigned to one or the other subspecies group in non-breeding plumage. Allopatric distributions, morphological differentiation and previously reported molecular divergence suggested the need for additional taxonomic study to assess the rank of these two populations. To resolve the taxonomy of the Buff-bellied Pipit species complex we analysed i) two mitochondrial DNA (mtDNA) loci and ii) nine bioacoustic parameters across 69 sound recordings (338 flight calls) recovered from public databases using principal component analysis and Euclidean distance measures. By comparing our mtDNA and call divergence measures with similar values measured between long-recognised species pairs of the genus, we show that the level of mitochondrial and acoustic divergence between the two Buff-bellied Pipit subspecies groups is typical of species-level divergence in the genus Anthus. Therefore, we recommend splitting the Buffbellied Pipit species complex into two species: Anthus rubescens (American Pipit) and Anthus japonicus (Siberian Pipit). Our results also suggest that the Water Pipit A. spinoletta deserves taxonomic reassessment as its lineages are highly divergent in acoustics and mtDNA, while mtDNA relationships suggest paraphyly relative to the Rock Pipit A. petrosus. Our work highlights the crucial importance of integrative approaches in taxonomy and the usefulness of bioacoustics in studying cryptic diversity.
Song is considered to play an important role in the maintenance of prezygotic reproductive isolat... more Song is considered to play an important role in the maintenance of prezygotic reproductive isolation between closely related songbird species. Therefore, song mixing in a contact zone between closely related species is often considered as evidence of hybridization. The Sichuan Leaf Warbler Phylloscopus forresti and the Gansu Leaf Warbler Phylloscopus kansuensis, which diverged 2 million years ago, have formed a contact zone in the south of the Gansu Province of China, where mixed songs have been observed. In this study, we investigated the potential causes and consequences of song mixing by integrating bioacoustic, morphological, mitochondrial, and genomic data with field ecological observations. We found that the two species display no apparent morphological differences, whereas their songs differ dramatically. We demonstrated that ∼11% of the males in the contact zone sang mixed songs. Two males singing mixed song were genotyped, and both were found to be P. kansuensis. Despite the presence of mixed singers, population genomic analyses detected no signs of recent gene flow between the two species, although two possible cases of mitochondrial introgression were identified. We conclude that the rather limited song mixing does not lead to, or result from, hybridization, and hence does not result in the breakdown of reproductive barriers between these cryptic species.
Background: In biological systems, biological diversity often displays a rapid turnover across el... more Background: In biological systems, biological diversity often displays a rapid turnover across elevations. This defining feature has made mountains classic systems for studying the spatial variation in diversity. Because patterns of elevational diversity can vary among lineages and mountain systems it remains difficult to extrapolate findings from one montane region to another, or among lineages. In this study, we assessed patterns and drivers of avian diversity along an elevational gradient on the eastern slope of Mt. Gongga, the highest peak in the Hengduan Mountain Range in central China, and a mountain where comprehensive studies of avian diversity are still lacking. Methods: We surveyed bird species in eight 400-m elevational bands from 1200 to 4400 m a.s.l. between 2012 and 2017. To test the relationship between bird species richness and environmental factors, we examined the relative importance of seven ecological variables on breeding season distribution patterns: land area (LA), mean daily temperature (MDT), seasonal temperature range (STR), the mid-domain effect (MDE), seasonal precipitation (SP), invertebrate biomass (IB) and enhanced vegetation index (EVI). Climate data were obtained from five local meteorological stations and three temperature/relative humidity smart sensors in 2016. Results: A total of 219 bird species were recorded in the field, of which 204 were recorded during the breeding season (April-August). Species richness curves (calculated separately for total species, large-ranged species, and smallranged species) were all hump-shaped. Large-ranged species contributed more to the total species richness pattern than small-ranged species. EVI and IB were positively correlated with total species richness and small-ranged species richness. LA and MDT were positively correlated with small-ranged species richness, while STR and SP were negatively correlated with small-ranged species richness. MDE was positively correlated with large-ranged species richness. When we considered the combination of candidate factors using multiple regression models and model-averaging, total species richness and large-ranged species richness were correlated with STR (negative) and MDE (positive), while small-ranged species richness was correlated with STR (negative) and IB (positive). Conclusions: Although no single key factor or suite of factors could explain patterns of diversity, we found that MDE, IB and STR play important but varying roles in shaping the elevational richness patterns of different bird species categories. Model-averaging indicates that small-ranged species appear to be mostly influenced by IB, as opposed to large-ranged species, which exhibit patterns more consistent with the MDE model. Our data also indicate that the species richness varied between seasons, offering a promising direction for future work.
When a new American warbler appeared in a supermarket car-park near Maidstone, within two days 35... more When a new American warbler appeared in a supermarket car-park near Maidstone, within two days 3500 people came from all over the country just to see it. The news spreads by word-of-mouth, by telephone hot-lines and via the media. In the UK bird recognition is a national sport. This book provides a field guide to the rare birds of Britain and Europe - describing and illustrating them - with all the non-European species ever recorded in Britain and Europe featured.
In the absence of nuclear-genomic differentiation between two populations, deep mitochondrial div... more In the absence of nuclear-genomic differentiation between two populations, deep mitochondrial divergence (DMD) is a form of mito-nuclear discordance. Such instances of DMD are rare and might variably be explained by unusual cases of female-linked selection, by male-biased dispersal, by "speciation reversal" or by mitochondrial capture through genetic introgression. Here, we analyze DMD in an Asian Phylloscopus leaf warbler (Aves: Phylloscopidae) complex. Bioacoustic, morphological, and genomic data demonstrate close similarity between the taxa affinis and occisinensis, even though DMD previously led to their classification as two distinct species. Using population genomic and comparative genomic methods on 45 whole genomes, including historical reconstructions of effective population size, genomic peaks of differentiation and genomic linkage, we infer that the form affinis is likely the product of a westward expansion in which it replaced a now-extinct congener that was the donor of its mtDNA and small portions of its nuclear genome. This study provides strong evidence of "ghost introgression" as the cause of DMD, and we suggest that "ghost introgression" may be a widely overlooked phenomenon in nature.
Patterns of heterogeneous genomic differentiation have been well documented between closely relat... more Patterns of heterogeneous genomic differentiation have been well documented between closely related species, with some highly differentiated genomic regions ("genomic differentiation islands") spread throughout the genome. Differential levels of gene flow are proposed to account for this pattern, as genomic differentiation islands are suggested to be resistant to gene flow. Recent studies have also suggested that genomic differentiation islands could be explained by linked selection acting on genomic regions with low recombination rates. Here, we investigate genomic differentiation and gene flow patterns for autosomes using RAD-seq data between two closely related species of long-tailed Accepted Article This article is protected by copyright. All rights reserved. tits (Aegithalos bonvaloti and A. fuliginosus) in both allopatric and contact zone populations. The results confirm recent or ongoing gene flow between these two species. However, there is little evidence that the genomic regions that were found to be highly differentiated between the contact zone populations are resistant to gene flow, suggesting that differential levels of gene flow is not the cause of the heterogeneous genomic differentiation. Linked selection may be the cause of genomic differentiation islands between the allopatric populations with no or very limited gene flow, but this could not account for the heterogeneous genomic differentiation between the contact zone populations, which show evidence of recent or ongoing gene flow.
bioRxiv (Cold Spring Harbor Laboratory), Apr 26, 2023
Instances of parallel phenotypic evolution offer great opportunities to understand the evolutiona... more Instances of parallel phenotypic evolution offer great opportunities to understand the evolutionary processes underlying phenotypic changes. However, confirming parallel phenotypic evolution and studying its causes requires a robust phylogenetic framework. One such example is the "black-andwhite wagtails", a group of five species in the songbird genus Motacilla: one species, the White Wagtail (M. alba), shows wide intra-specific plumage variation, while the four others form two pairs of very similar-looking species (African Pied Wagtail M. aguimp + Mekong Wagtail M. samveasnae and Japanese Wagtail M. grandis + White-browed Wagtail M. maderaspatensis, respectively). However, the two species in each of these pairs were not recovered as sisters in previous phylogenetic inferences. Their relationships varied depending on the markers used, suggesting that gene tree heterogeneity might have hampered accurate phylogenetic inference. Here, we use whole genome resequencing data to explore the phylogenetic relationships within this group, with a special emphasis on characterizing the extent of gene tree heterogeneity and its underlying causes. We first used multispecies coalescent methods to generate a "complete evidence" phylogenetic hypothesis based on genome-wide variants, while accounting for incomplete lineage sorting and introgression. We then investigated the variation in phylogenetic signal across the genome, to quantify the extent of discordance across genomic regions, and test its underlying causes. We found that wagtail genomes are mosaics of regions supporting variable genealogies, because of ILS and inter-specific introgression. The most common topology across the genome, supporting M. alba and M. aguimp as sister species, appears to be influenced by ancient introgression. Additionally, we inferred another ancient introgression event, between M. alba and M. grandis. By combining results from multiple analyses, we propose a phylogenetic network for the black-and-white wagtails that confirms that similar phenotypes evolved in non-sister lineages, supporting parallel plumage evolution. Furthermore, the inferred reticulations do not connect species with similar plumage coloration, suggesting that introgression does not underlie parallel plumage evolution in this group. Our results demonstrate the importance of investigation of genome-wide patterns of gene tree heterogeneity to help understanding the mechanisms underlying phenotypic evolution. .
Aim: Variation in species diversity among different geographical areas may result from difference... more Aim: Variation in species diversity among different geographical areas may result from differences in speciation and extinction rates, immigration and time for diversification. An area with high species diversity may be the result of a high net diversification rate, multiple immigration events from adjacent regions, and a long time available for the accumulation of species (known as the 'time-for-speciation effect'). Here, we examine the relative importance of the three aforementioned processes in shaping the geographical diversity patterns of a large radiation of passerine birds. Location: Global. Taxon: Babblers (Aves: Passeriformes). Methods: Using a comprehensive phylogeny of extant species (~90% sampled) and distributions of the world's babblers, we reconstructed their biogeographical history and analysed the diversification dynamics. We examined how species richness correlates with the timing of regional colonization, the number of immigration events and the rate of speciation within all 13 geographical distribution regions. Results: We found that babblers likely originated in the Sino-Himalayan Mountains (SHM) in the early Miocene, suggesting a long time for diversification and species accumulation within the SHM. Regression analyses showed the regional diversity of babblers can be well explained by the timing of the first colonization within of these areas, while differences in rates of speciation or immigration have far weaker effects. Nonetheless, the rapid speciation of Zosterops during the Pleistocene has accounted for the increased diversification and accumulation of species in the oceanic islands. Main Conclusions: Our results suggest that the global diversity patterns of babblers have predominantly been shaped by the time-for-speciation effect. Our findings also support an origin centred in tropical and subtropical parts of the SHM, with a cradle of recent diversification in the oceanic islands of the Indo-Pacific and Indian Ocean regions, which provides new insights into the generation of global biodiversity hotspots. | 1613 CAI et Al.
D enna pdf är en något modifierad, ompagi nerad sammanslagning av två artiklar pub licerade i Fau... more D enna pdf är en något modifierad, ompagi nerad sammanslagning av två artiklar pub licerade i Fauna och Flora (2014:4 och 2015:1). Här finns också en fullständig litteraturlista, vilken inte finns med i de tryckta versionerna. Artiklarna ska citeras enligt följande: Träskonäbb Balaeniceps rex, länge betraktad som en släkting till storkfåglar, numera placerad närmare pelikanfåglar. Foto: Ragnar Hall fauna&flora 2 Faktaruta 1: Klassificering Alla organismer klassificeras i dag i ett hierarkiskt system som syftar till att spegla deras släktskap. Enligt modern systematik ska åtminstone alla kategorier över art representera monofyletiska grupper (se Fig. 1 nästa uppslag). Det är arten som utgör systemets bas. Närbesläktade arter grupperas i olika släkten. Släkten inordnas i familjer, familjer i ordningar, ordningar i klasser, klasser i stammar (fyla, singularis fylum) och stammar i domä nerna eukaryoter, eubakterier eller arkéer. För alla taxa kan det finnas över-respektive undergrupper, t.ex. överfamilj och underfamilj. Det är också vanligt att arter delas in i underarter (= raser). Kategori Exempel Domän Eukarya (eukaryoter) Stam (fylum) Chordata (ryggsträngsdjur) Understam Craniata (kraniedjur) Infrastam Vertebrata (ryggradsdjur) Klass Aves (fåglar) Ordning Anseriformes (andfåglar) Familj Anatidae (änder och gäss) Släkte Anser ("grå" gäss) Art Anser anser (grågås) Underart (= ras) Anser anser anser ("västlig" grågås)
ABSTRACTMountain biotas have considerable conservation and research importance, but the formation... more ABSTRACTMountain biotas have considerable conservation and research importance, but the formation of montane communities remains incompletely understood. Study of Indo-Pacific island faunas has inspired two main hypotheses for the generation of montane diversity. The first posits that montane populations arise via direct colonization from other mountain areas, while the second invokes recruitment from adjacent lowland populations. We sought to reconcile these apparently conflicting hypotheses by asking whether a species’ ancestral geographic origin determines its mode of mountain colonization. To this end, island-dwelling passerine birds at the faunal crossroads between Eurasia and Australo-Papua provide an ideal study system. We recovered the phylogenetic relationships of the region’s montane species, and used this information to reconstruct their ancestral geographic ranges, elevational ranges, and migratory behavior. We also performed genomic population studies of three super-dis...
The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubesce... more The Buff-bellied Pipit Anthus rubescens comprises two allopatric subspecies groups: A. r. rubescens and A. r. alticola in North America and A. [r.] japonicus in northeast Asia. Despite their great morphological resemblance in breeding plumage, most individuals can be assigned to one or the other subspecies group in non-breeding plumage. Allopatric distributions, morphological differentiation and previously reported molecular divergence suggested the need for additional taxonomic study to assess the rank of these two populations. To resolve the taxonomy of the Buff-bellied Pipit species complex we analysed i) two mitochondrial DNA (mtDNA) loci and ii) nine bioacoustic parameters across 69 sound recordings (338 flight calls) recovered from public databases using principal component analysis and Euclidean distance measures. By comparing our mtDNA and call divergence measures with similar values measured between long-recognised species pairs of the genus, we show that the level of mitochondrial and acoustic divergence between the two Buff-bellied Pipit subspecies groups is typical of species-level divergence in the genus Anthus. Therefore, we recommend splitting the Buffbellied Pipit species complex into two species: Anthus rubescens (American Pipit) and Anthus japonicus (Siberian Pipit). Our results also suggest that the Water Pipit A. spinoletta deserves taxonomic reassessment as its lineages are highly divergent in acoustics and mtDNA, while mtDNA relationships suggest paraphyly relative to the Rock Pipit A. petrosus. Our work highlights the crucial importance of integrative approaches in taxonomy and the usefulness of bioacoustics in studying cryptic diversity.
Song is considered to play an important role in the maintenance of prezygotic reproductive isolat... more Song is considered to play an important role in the maintenance of prezygotic reproductive isolation between closely related songbird species. Therefore, song mixing in a contact zone between closely related species is often considered as evidence of hybridization. The Sichuan Leaf Warbler Phylloscopus forresti and the Gansu Leaf Warbler Phylloscopus kansuensis, which diverged 2 million years ago, have formed a contact zone in the south of the Gansu Province of China, where mixed songs have been observed. In this study, we investigated the potential causes and consequences of song mixing by integrating bioacoustic, morphological, mitochondrial, and genomic data with field ecological observations. We found that the two species display no apparent morphological differences, whereas their songs differ dramatically. We demonstrated that ∼11% of the males in the contact zone sang mixed songs. Two males singing mixed song were genotyped, and both were found to be P. kansuensis. Despite the presence of mixed singers, population genomic analyses detected no signs of recent gene flow between the two species, although two possible cases of mitochondrial introgression were identified. We conclude that the rather limited song mixing does not lead to, or result from, hybridization, and hence does not result in the breakdown of reproductive barriers between these cryptic species.
Background: In biological systems, biological diversity often displays a rapid turnover across el... more Background: In biological systems, biological diversity often displays a rapid turnover across elevations. This defining feature has made mountains classic systems for studying the spatial variation in diversity. Because patterns of elevational diversity can vary among lineages and mountain systems it remains difficult to extrapolate findings from one montane region to another, or among lineages. In this study, we assessed patterns and drivers of avian diversity along an elevational gradient on the eastern slope of Mt. Gongga, the highest peak in the Hengduan Mountain Range in central China, and a mountain where comprehensive studies of avian diversity are still lacking. Methods: We surveyed bird species in eight 400-m elevational bands from 1200 to 4400 m a.s.l. between 2012 and 2017. To test the relationship between bird species richness and environmental factors, we examined the relative importance of seven ecological variables on breeding season distribution patterns: land area (LA), mean daily temperature (MDT), seasonal temperature range (STR), the mid-domain effect (MDE), seasonal precipitation (SP), invertebrate biomass (IB) and enhanced vegetation index (EVI). Climate data were obtained from five local meteorological stations and three temperature/relative humidity smart sensors in 2016. Results: A total of 219 bird species were recorded in the field, of which 204 were recorded during the breeding season (April-August). Species richness curves (calculated separately for total species, large-ranged species, and smallranged species) were all hump-shaped. Large-ranged species contributed more to the total species richness pattern than small-ranged species. EVI and IB were positively correlated with total species richness and small-ranged species richness. LA and MDT were positively correlated with small-ranged species richness, while STR and SP were negatively correlated with small-ranged species richness. MDE was positively correlated with large-ranged species richness. When we considered the combination of candidate factors using multiple regression models and model-averaging, total species richness and large-ranged species richness were correlated with STR (negative) and MDE (positive), while small-ranged species richness was correlated with STR (negative) and IB (positive). Conclusions: Although no single key factor or suite of factors could explain patterns of diversity, we found that MDE, IB and STR play important but varying roles in shaping the elevational richness patterns of different bird species categories. Model-averaging indicates that small-ranged species appear to be mostly influenced by IB, as opposed to large-ranged species, which exhibit patterns more consistent with the MDE model. Our data also indicate that the species richness varied between seasons, offering a promising direction for future work.
When a new American warbler appeared in a supermarket car-park near Maidstone, within two days 35... more When a new American warbler appeared in a supermarket car-park near Maidstone, within two days 3500 people came from all over the country just to see it. The news spreads by word-of-mouth, by telephone hot-lines and via the media. In the UK bird recognition is a national sport. This book provides a field guide to the rare birds of Britain and Europe - describing and illustrating them - with all the non-European species ever recorded in Britain and Europe featured.
In the absence of nuclear-genomic differentiation between two populations, deep mitochondrial div... more In the absence of nuclear-genomic differentiation between two populations, deep mitochondrial divergence (DMD) is a form of mito-nuclear discordance. Such instances of DMD are rare and might variably be explained by unusual cases of female-linked selection, by male-biased dispersal, by "speciation reversal" or by mitochondrial capture through genetic introgression. Here, we analyze DMD in an Asian Phylloscopus leaf warbler (Aves: Phylloscopidae) complex. Bioacoustic, morphological, and genomic data demonstrate close similarity between the taxa affinis and occisinensis, even though DMD previously led to their classification as two distinct species. Using population genomic and comparative genomic methods on 45 whole genomes, including historical reconstructions of effective population size, genomic peaks of differentiation and genomic linkage, we infer that the form affinis is likely the product of a westward expansion in which it replaced a now-extinct congener that was the donor of its mtDNA and small portions of its nuclear genome. This study provides strong evidence of "ghost introgression" as the cause of DMD, and we suggest that "ghost introgression" may be a widely overlooked phenomenon in nature.
Patterns of heterogeneous genomic differentiation have been well documented between closely relat... more Patterns of heterogeneous genomic differentiation have been well documented between closely related species, with some highly differentiated genomic regions ("genomic differentiation islands") spread throughout the genome. Differential levels of gene flow are proposed to account for this pattern, as genomic differentiation islands are suggested to be resistant to gene flow. Recent studies have also suggested that genomic differentiation islands could be explained by linked selection acting on genomic regions with low recombination rates. Here, we investigate genomic differentiation and gene flow patterns for autosomes using RAD-seq data between two closely related species of long-tailed Accepted Article This article is protected by copyright. All rights reserved. tits (Aegithalos bonvaloti and A. fuliginosus) in both allopatric and contact zone populations. The results confirm recent or ongoing gene flow between these two species. However, there is little evidence that the genomic regions that were found to be highly differentiated between the contact zone populations are resistant to gene flow, suggesting that differential levels of gene flow is not the cause of the heterogeneous genomic differentiation. Linked selection may be the cause of genomic differentiation islands between the allopatric populations with no or very limited gene flow, but this could not account for the heterogeneous genomic differentiation between the contact zone populations, which show evidence of recent or ongoing gene flow.
bioRxiv (Cold Spring Harbor Laboratory), Apr 26, 2023
Instances of parallel phenotypic evolution offer great opportunities to understand the evolutiona... more Instances of parallel phenotypic evolution offer great opportunities to understand the evolutionary processes underlying phenotypic changes. However, confirming parallel phenotypic evolution and studying its causes requires a robust phylogenetic framework. One such example is the "black-andwhite wagtails", a group of five species in the songbird genus Motacilla: one species, the White Wagtail (M. alba), shows wide intra-specific plumage variation, while the four others form two pairs of very similar-looking species (African Pied Wagtail M. aguimp + Mekong Wagtail M. samveasnae and Japanese Wagtail M. grandis + White-browed Wagtail M. maderaspatensis, respectively). However, the two species in each of these pairs were not recovered as sisters in previous phylogenetic inferences. Their relationships varied depending on the markers used, suggesting that gene tree heterogeneity might have hampered accurate phylogenetic inference. Here, we use whole genome resequencing data to explore the phylogenetic relationships within this group, with a special emphasis on characterizing the extent of gene tree heterogeneity and its underlying causes. We first used multispecies coalescent methods to generate a "complete evidence" phylogenetic hypothesis based on genome-wide variants, while accounting for incomplete lineage sorting and introgression. We then investigated the variation in phylogenetic signal across the genome, to quantify the extent of discordance across genomic regions, and test its underlying causes. We found that wagtail genomes are mosaics of regions supporting variable genealogies, because of ILS and inter-specific introgression. The most common topology across the genome, supporting M. alba and M. aguimp as sister species, appears to be influenced by ancient introgression. Additionally, we inferred another ancient introgression event, between M. alba and M. grandis. By combining results from multiple analyses, we propose a phylogenetic network for the black-and-white wagtails that confirms that similar phenotypes evolved in non-sister lineages, supporting parallel plumage evolution. Furthermore, the inferred reticulations do not connect species with similar plumage coloration, suggesting that introgression does not underlie parallel plumage evolution in this group. Our results demonstrate the importance of investigation of genome-wide patterns of gene tree heterogeneity to help understanding the mechanisms underlying phenotypic evolution. .
Aim: Variation in species diversity among different geographical areas may result from difference... more Aim: Variation in species diversity among different geographical areas may result from differences in speciation and extinction rates, immigration and time for diversification. An area with high species diversity may be the result of a high net diversification rate, multiple immigration events from adjacent regions, and a long time available for the accumulation of species (known as the 'time-for-speciation effect'). Here, we examine the relative importance of the three aforementioned processes in shaping the geographical diversity patterns of a large radiation of passerine birds. Location: Global. Taxon: Babblers (Aves: Passeriformes). Methods: Using a comprehensive phylogeny of extant species (~90% sampled) and distributions of the world's babblers, we reconstructed their biogeographical history and analysed the diversification dynamics. We examined how species richness correlates with the timing of regional colonization, the number of immigration events and the rate of speciation within all 13 geographical distribution regions. Results: We found that babblers likely originated in the Sino-Himalayan Mountains (SHM) in the early Miocene, suggesting a long time for diversification and species accumulation within the SHM. Regression analyses showed the regional diversity of babblers can be well explained by the timing of the first colonization within of these areas, while differences in rates of speciation or immigration have far weaker effects. Nonetheless, the rapid speciation of Zosterops during the Pleistocene has accounted for the increased diversification and accumulation of species in the oceanic islands. Main Conclusions: Our results suggest that the global diversity patterns of babblers have predominantly been shaped by the time-for-speciation effect. Our findings also support an origin centred in tropical and subtropical parts of the SHM, with a cradle of recent diversification in the oceanic islands of the Indo-Pacific and Indian Ocean regions, which provides new insights into the generation of global biodiversity hotspots. | 1613 CAI et Al.
D enna pdf är en något modifierad, ompagi nerad sammanslagning av två artiklar pub licerade i Fau... more D enna pdf är en något modifierad, ompagi nerad sammanslagning av två artiklar pub licerade i Fauna och Flora (2014:4 och 2015:1). Här finns också en fullständig litteraturlista, vilken inte finns med i de tryckta versionerna. Artiklarna ska citeras enligt följande: Träskonäbb Balaeniceps rex, länge betraktad som en släkting till storkfåglar, numera placerad närmare pelikanfåglar. Foto: Ragnar Hall fauna&flora 2 Faktaruta 1: Klassificering Alla organismer klassificeras i dag i ett hierarkiskt system som syftar till att spegla deras släktskap. Enligt modern systematik ska åtminstone alla kategorier över art representera monofyletiska grupper (se Fig. 1 nästa uppslag). Det är arten som utgör systemets bas. Närbesläktade arter grupperas i olika släkten. Släkten inordnas i familjer, familjer i ordningar, ordningar i klasser, klasser i stammar (fyla, singularis fylum) och stammar i domä nerna eukaryoter, eubakterier eller arkéer. För alla taxa kan det finnas över-respektive undergrupper, t.ex. överfamilj och underfamilj. Det är också vanligt att arter delas in i underarter (= raser). Kategori Exempel Domän Eukarya (eukaryoter) Stam (fylum) Chordata (ryggsträngsdjur) Understam Craniata (kraniedjur) Infrastam Vertebrata (ryggradsdjur) Klass Aves (fåglar) Ordning Anseriformes (andfåglar) Familj Anatidae (änder och gäss) Släkte Anser ("grå" gäss) Art Anser anser (grågås) Underart (= ras) Anser anser anser ("västlig" grågås)
ABSTRACTMountain biotas have considerable conservation and research importance, but the formation... more ABSTRACTMountain biotas have considerable conservation and research importance, but the formation of montane communities remains incompletely understood. Study of Indo-Pacific island faunas has inspired two main hypotheses for the generation of montane diversity. The first posits that montane populations arise via direct colonization from other mountain areas, while the second invokes recruitment from adjacent lowland populations. We sought to reconcile these apparently conflicting hypotheses by asking whether a species’ ancestral geographic origin determines its mode of mountain colonization. To this end, island-dwelling passerine birds at the faunal crossroads between Eurasia and Australo-Papua provide an ideal study system. We recovered the phylogenetic relationships of the region’s montane species, and used this information to reconstruct their ancestral geographic ranges, elevational ranges, and migratory behavior. We also performed genomic population studies of three super-dis...
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