ABSTRACT Relationships of the Neotropical finches in the genera Euphonia and Chlorophonia (Fringillidae: Euphoniinae) have been clarified by recent molecular studies, but species-level relationships within this group have not been thoroughly addressed. In this study, we sampled specimens representing every recognized species of these genera, in addition to 2 outgroup taxa, and used target enrichment to sequence thousands of ultraconserved element (UCE) loci, as well as mitochondrial DNA reconstructed from off-target reads, from each specimen to infer these relationships. We constructed both concatenation and coalescent-based estimates of phylogeny from this dataset using matrices of varying levels of completeness, and we generated a time-scaled ultrametric tree using a recently published fossil-based external calibration. We found uniformly strong support for a monophyletic subfamily Euphoniinae and genus Chlorophonia, but a paraphyletic Euphonia across UCEs and mitochondrial genomes. Otherwise, our inferred relationships were largely concordant with previous studies. Our time-tree indicated a stem divergence time of 13.8 million years ago for this lineage, followed by a relatively young crown age of only 7.1 myr. Reconstructions of biogeographic history based on this tree suggest a South American origin for crown Euphoniinae, possibly resulting from a transoceanic dispersal event from the Eastern Hemisphere, followed by 2 dispersal events into the Caribbean and as many as 6 invasions of North America coinciding with recent estimates of the age at which the Isthmus of Panama had completely formed. We recommend splitting Euphonia and resurrecting the genus Cyanophonia for the 3 blue-hooded species more closely related to Chlorophonia. Based on our results, we suspect that there is undescribed species-level diversity in at least one, possibly many, widespread and phenotypically diverse species.
{"title":"Mitochondrial genomes and thousands of ultraconserved elements resolve the taxonomy and historical biogeography of the Euphonia and Chlorophonia finches (Passeriformes: Fringillidae)","authors":"Tyler S Imfeld, F. Barker, R. T. Brumfield","doi":"10.1093/auk/ukaa016","DOIUrl":"https://doi.org/10.1093/auk/ukaa016","url":null,"abstract":"ABSTRACT Relationships of the Neotropical finches in the genera Euphonia and Chlorophonia (Fringillidae: Euphoniinae) have been clarified by recent molecular studies, but species-level relationships within this group have not been thoroughly addressed. In this study, we sampled specimens representing every recognized species of these genera, in addition to 2 outgroup taxa, and used target enrichment to sequence thousands of ultraconserved element (UCE) loci, as well as mitochondrial DNA reconstructed from off-target reads, from each specimen to infer these relationships. We constructed both concatenation and coalescent-based estimates of phylogeny from this dataset using matrices of varying levels of completeness, and we generated a time-scaled ultrametric tree using a recently published fossil-based external calibration. We found uniformly strong support for a monophyletic subfamily Euphoniinae and genus Chlorophonia, but a paraphyletic Euphonia across UCEs and mitochondrial genomes. Otherwise, our inferred relationships were largely concordant with previous studies. Our time-tree indicated a stem divergence time of 13.8 million years ago for this lineage, followed by a relatively young crown age of only 7.1 myr. Reconstructions of biogeographic history based on this tree suggest a South American origin for crown Euphoniinae, possibly resulting from a transoceanic dispersal event from the Eastern Hemisphere, followed by 2 dispersal events into the Caribbean and as many as 6 invasions of North America coinciding with recent estimates of the age at which the Isthmus of Panama had completely formed. We recommend splitting Euphonia and resurrecting the genus Cyanophonia for the 3 blue-hooded species more closely related to Chlorophonia. Based on our results, we suspect that there is undescribed species-level diversity in at least one, possibly many, widespread and phenotypically diverse species.","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127916900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This book tackles one of the most important and debated innovations in the evolution of life, the evolution of endothermy in mammal and bird lineages. Barry Lovegrove presents a lucid critique of current models of the evolution of endothermy, particularly single-cause models, and presents a novel “triphasic” model for which endothermy evolves in pulses throughout the history of mammals and birds in response to several selective factors. The ideas presented within this book will surely generate discussions and help advance the field. I will confess that my major professor during my Ph.D. program was John Ruben, coauthor of “Endothermy and activity in vertebrates” (Bennett and Ruben 1979), an early and influential presentation of the aerobic capacity model for the evolution of endothermy, so I am vested in the logic behind that argument. Consequently, I naturally approached this book with aerobic capacity model preconceptions and a critical eye. The book is divided into 2 parts: the first 9 chapters collectively focus on fossils and paleoclimates relevant to the evolution of endothermy, and the second 9 focus on patterns of thermoregulation in extant birds and mammals and their evolutionary implications. Three appendices provide descriptions of heat-generating pathways available to vertebrates, discussions of nasal evaporative cooling, water balance and energetics, and a vertebrate phylogeny including aforementioned fossil and extant organisms. Lovegrove defines endothermy as “the capacity to produce heat on demand from within an animal” (p. 6), and argues that basal metabolic rate (i.e. minimum existence metabolic rate) is primarily generated from metabolic activity in central organs (e.g., heart, kidney, liver, intestines) rather than muscles. Considering basal and exercise or thermogenic metabolic rates as processes controlled primarily by central and exercise organs, respectively, is a useful generalization. It is, however, not strictly correct, perhaps especially for birds whose large flight muscle masses require resting maintenance costs that often contribute significantly to basal metabolic rate (e.g., Chappell et al. 1999). Nevertheless, the idea that basal and maximal metabolic rates may not be tightly coupled phenotypically, at least in extant vertebrates (e.g., Petit et al. 2013, Swanson et al. 2017), as predicted by the aerobic capacity model, provides fodder for other evolutionary scenarios. Chapter 2 reviews terrestrial adaptations in early tetrapods that facilitated the evolution of endothermy, including the amniotic egg and adaptations to reduce water loss, to allow for terrestrial locomotion, and to digest land applyparastyle "fig//caption/p[1]" parastyle "FigCapt"
这本书解决了生命进化中最重要和有争议的创新之一，哺乳动物和鸟类血统的恒温动物的进化。巴里·洛夫格罗夫(Barry Lovegrove)对当前的恒温动物进化模型，特别是单原因模型进行了清晰的批判，并提出了一个新的“三相”模型，该模型认为，在哺乳动物和鸟类的整个历史中，恒温动物在几个选择因素的影响下以脉冲方式进化。本书中提出的观点肯定会引发讨论，并有助于推动该领域的发展。我得承认，在我读博士期间，我的主要教授是约翰·鲁本(John Ruben)，他是《脊椎动物的恒温动物和活动》(Bennett and Ruben 1979)的合著者之一，这本书是关于恒温动物进化的有氧能力模型的早期和有影响力的介绍，所以我被赋予了这个论点背后的逻辑。因此，我很自然地带着有氧能力模型的先入为主和批判的眼光来看待这本书。本书分为两部分:前9章集中于与恒温动物进化相关的化石和古气候，后9章集中于现存鸟类和哺乳动物的体温调节模式及其进化意义。三个附录描述了脊椎动物的发热途径，讨论了鼻腔蒸发冷却、水平衡和能量学，以及包括上述化石和现存生物在内的脊椎动物系统发育。Lovegrove将恒温动物定义为“动物体内根据需要产生热量的能力”(第6页)，并认为基础代谢率(即最低存在代谢率)主要来自中心器官(如心脏、肾脏、肝脏、肠道)的代谢活动，而不是肌肉。将基础代谢率和运动代谢率或热代谢率分别视为主要由中枢和运动器官控制的过程，是一个有用的概括。然而，这并不是严格正确的，尤其是对于那些大的飞行肌肉群需要静息维持成本的鸟类来说，这通常对基础代谢率有很大的影响(例如，Chappell et al. 1999)。然而，至少在现存的脊椎动物(例如，Petit et al. 2013, Swanson et al. 2017)中，基础代谢率和最大代谢率在表型上可能不是紧密耦合的，这一观点正如有氧能力模型所预测的那样，为其他进化情景提供了依据。第二章回顾了早期四足动物对陆地的适应，这些适应促进了恒温动物的进化，包括羊膜卵和减少水分流失、允许陆地运动和消化陆地应用的适应。
{"title":"Fires of Life: Endothermy in Birds and Mammals","authors":"D. Swanson","doi":"10.1093/auk/ukaa020","DOIUrl":"https://doi.org/10.1093/auk/ukaa020","url":null,"abstract":"This book tackles one of the most important and debated innovations in the evolution of life, the evolution of endothermy in mammal and bird lineages. Barry Lovegrove presents a lucid critique of current models of the evolution of endothermy, particularly single-cause models, and presents a novel “triphasic” model for which endothermy evolves in pulses throughout the history of mammals and birds in response to several selective factors. The ideas presented within this book will surely generate discussions and help advance the field. I will confess that my major professor during my Ph.D. program was John Ruben, coauthor of “Endothermy and activity in vertebrates” (Bennett and Ruben 1979), an early and influential presentation of the aerobic capacity model for the evolution of endothermy, so I am vested in the logic behind that argument. Consequently, I naturally approached this book with aerobic capacity model preconceptions and a critical eye. The book is divided into 2 parts: the first 9 chapters collectively focus on fossils and paleoclimates relevant to the evolution of endothermy, and the second 9 focus on patterns of thermoregulation in extant birds and mammals and their evolutionary implications. Three appendices provide descriptions of heat-generating pathways available to vertebrates, discussions of nasal evaporative cooling, water balance and energetics, and a vertebrate phylogeny including aforementioned fossil and extant organisms. Lovegrove defines endothermy as “the capacity to produce heat on demand from within an animal” (p. 6), and argues that basal metabolic rate (i.e. minimum existence metabolic rate) is primarily generated from metabolic activity in central organs (e.g., heart, kidney, liver, intestines) rather than muscles. Considering basal and exercise or thermogenic metabolic rates as processes controlled primarily by central and exercise organs, respectively, is a useful generalization. It is, however, not strictly correct, perhaps especially for birds whose large flight muscle masses require resting maintenance costs that often contribute significantly to basal metabolic rate (e.g., Chappell et al. 1999). Nevertheless, the idea that basal and maximal metabolic rates may not be tightly coupled phenotypically, at least in extant vertebrates (e.g., Petit et al. 2013, Swanson et al. 2017), as predicted by the aerobic capacity model, provides fodder for other evolutionary scenarios. Chapter 2 reviews terrestrial adaptations in early tetrapods that facilitated the evolution of endothermy, including the amniotic egg and adaptations to reduce water loss, to allow for terrestrial locomotion, and to digest land applyparastyle \"fig//caption/p[1]\" parastyle \"FigCapt\"","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120977396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Robert Craig Whitmore, 1947–2019","authors":"James T. Anderson, Kevin Dodge","doi":"10.1093/auk/ukaa013","DOIUrl":"https://doi.org/10.1093/auk/ukaa013","url":null,"abstract":"","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124623287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Remacha, César Rodríguez, J. de la Puente, J. Pérez‐Tris
ABSTRACT Contemporary phenotypic trends associated with global change are widely documented, but whether such trends always denote trait optimization under changed conditions remains obscure. Natural selection has shaped the wings of long-distance migratory birds to minimize the costs of transport, and new optimal wing shapes could be promoted by migration patterns altered due to global change. Alternatively, wing shape could vary as a correlated response to selection on other traits favored in a changing environment, eventually moving away from the optimal shape for migration and increasing transport costs. Data from 20 yr of monitoring 2 Common Nightingale (Luscinia megarhynchos) populations breeding in central Spain, where environmental conditions for breeding have deteriorated during recent decades due to increased summer drought, show that birds have reduced wing length relative to body size over the period 1995–2014. However, long-winged nightingales survived their first round-trip migration better, and the shorter the average wing length of individuals, the stronger the survival-associated natural selection favoring longer wings. Maladaptive short wings may have arisen because the mortality costs of migration are outweighed by reproductive benefits accrued by short-winged nightingales in these populations. Assuming that the phenotypic integration of morphological and reproductive adaptations of migratory birds has a genetic basis, we hypothesize that the maladaptive trend towards shorter wings may be a correlated response to selection for moderate breeding investment in drying habitat. Our results provide evidence that contemporary phenotypic change may deviate average trait values from their optima, thereby increasing our understanding of the ecological constraints underpinning adaptation to rapid global change.
{"title":"Climate change and maladaptive wing shortening in a long-distance migratory bird","authors":"C. Remacha, César Rodríguez, J. de la Puente, J. Pérez‐Tris","doi":"10.1093/auk/ukaa012","DOIUrl":"https://doi.org/10.1093/auk/ukaa012","url":null,"abstract":"ABSTRACT Contemporary phenotypic trends associated with global change are widely documented, but whether such trends always denote trait optimization under changed conditions remains obscure. Natural selection has shaped the wings of long-distance migratory birds to minimize the costs of transport, and new optimal wing shapes could be promoted by migration patterns altered due to global change. Alternatively, wing shape could vary as a correlated response to selection on other traits favored in a changing environment, eventually moving away from the optimal shape for migration and increasing transport costs. Data from 20 yr of monitoring 2 Common Nightingale (Luscinia megarhynchos) populations breeding in central Spain, where environmental conditions for breeding have deteriorated during recent decades due to increased summer drought, show that birds have reduced wing length relative to body size over the period 1995–2014. However, long-winged nightingales survived their first round-trip migration better, and the shorter the average wing length of individuals, the stronger the survival-associated natural selection favoring longer wings. Maladaptive short wings may have arisen because the mortality costs of migration are outweighed by reproductive benefits accrued by short-winged nightingales in these populations. Assuming that the phenotypic integration of morphological and reproductive adaptations of migratory birds has a genetic basis, we hypothesize that the maladaptive trend towards shorter wings may be a correlated response to selection for moderate breeding investment in drying habitat. Our results provide evidence that contemporary phenotypic change may deviate average trait values from their optima, thereby increasing our understanding of the ecological constraints underpinning adaptation to rapid global change.","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130434843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"James Francis Bendell, 1926–2020","authors":"Brian J. Naylor, K. Szuba","doi":"10.1093/auk/ukaa014","DOIUrl":"https://doi.org/10.1093/auk/ukaa014","url":null,"abstract":"","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125714618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wiliam Ku-Peralta, Adolfo G. Navarro‐Sigüenza, L. Sandoval, J. Sosa-López
ABSTRACT Acoustic signals used in animal communication play a key role in mate attraction, species recognition, and territory defense. Variation in acoustic signals may reflect population structure, lack of gene flow, and phylogenetic relationships. In birds, the study of geographic variation in acoustic signals has been useful for elucidating potential factors involved in phenotypic divergence and for establishing species limits. However, most of the studies on geographic variation have focused on calls and solo songs, with few studies focusing on complex behaviors such as duets. In this study, we investigated the variation in the duets of the Rufous-naped Wren (Campylorhynchus rufinucha). Our results suggest that duets vary across the distribution range of the species complex, matching the 3 taxonomic groups previously suggested (rufinucha, humilis, and capistratus). We also found a marked song sexual dimorphism in 2 groups, rufinucha and humilis, that is lacking in capistratus. At the local level, we found that duets also vary among sites within groups, but less than between groups. Our results suggest that groups rufinucha and humilis sing the most similar duets, whereas capistratus performs the most divergent duets of the 3 groups. Further, when comparing duet variation across geography, we found that birds living closer to each other sing more similar duets. We suggest that the existence of 3 vocal lineages is probably the result of historical geographic isolation followed by other selective (i.e. sexual selection, social selection, habitat structure) and/or non-selective factors (i.e. drift, isolation by distance), and that variation found within groups may be the result of cultural drift or social selection.
{"title":"Geographic variation in the duets of the Rufous-naped Wren (Campylorhynchus rufinucha) complex","authors":"Wiliam Ku-Peralta, Adolfo G. Navarro‐Sigüenza, L. Sandoval, J. Sosa-López","doi":"10.1093/auk/ukaa015","DOIUrl":"https://doi.org/10.1093/auk/ukaa015","url":null,"abstract":"ABSTRACT Acoustic signals used in animal communication play a key role in mate attraction, species recognition, and territory defense. Variation in acoustic signals may reflect population structure, lack of gene flow, and phylogenetic relationships. In birds, the study of geographic variation in acoustic signals has been useful for elucidating potential factors involved in phenotypic divergence and for establishing species limits. However, most of the studies on geographic variation have focused on calls and solo songs, with few studies focusing on complex behaviors such as duets. In this study, we investigated the variation in the duets of the Rufous-naped Wren (Campylorhynchus rufinucha). Our results suggest that duets vary across the distribution range of the species complex, matching the 3 taxonomic groups previously suggested (rufinucha, humilis, and capistratus). We also found a marked song sexual dimorphism in 2 groups, rufinucha and humilis, that is lacking in capistratus. At the local level, we found that duets also vary among sites within groups, but less than between groups. Our results suggest that groups rufinucha and humilis sing the most similar duets, whereas capistratus performs the most divergent duets of the 3 groups. Further, when comparing duet variation across geography, we found that birds living closer to each other sing more similar duets. We suggest that the existence of 3 vocal lineages is probably the result of historical geographic isolation followed by other selective (i.e. sexual selection, social selection, habitat structure) and/or non-selective factors (i.e. drift, isolation by distance), and that variation found within groups may be the result of cultural drift or social selection.","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132408941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anthony Hemingway “Tony” Bledsoe died at the age of 62 on September 14, 2019. Tony was an outstanding ornithologist, life-long birdwatcher, and most of all an inspirational teacher of ecology and evolution. He was an Elective Member (1990) of the American Ornithologists’ Union (AOU), Director of the Ornithological Societies of North America (1998–2000), Assistant to the AOU Treasurer (1996–2000), a key organizer of the AOU’s annual meeting in Pittsburgh (1989), and a founding member of the Connecticut Ornithological Association (1983). Tony was born to Carter and Phyllis Bledsoe in Washington, D.C., on October 10, 1956, but grew up on the Main Line of Philadelphia, graduating from Lower Merion High School. As a young natural history enthusiast, he volunteered to work in the collections at the Academy of Natural Sciences of Philadelphia, where he was inspired to “think clearly” about evolutionary issues by Frank Gill and herpetologist Tom Uzzell. Following high school, Tony attended the University of California, Santa Cruz, where he honed his birdwatching and natural history skills. In 1978, he started his PhD studies in the laboratory of Charles Sibley at Yale University. At the time molecular systematics was a small field, and studies using DNA were rare. With huge intellectual curiosity and boyish naiveté, Tony jumped into the program and soon became an expert in all aspects of phylogenetics. At the time, cladistic morphology was in its full glory, and antipathy toward Sibley’s DNA hybridization, which was viewed (inaccurately) as phenetic and thus hopelessly flawed, led to epic philosophical battles. Tony threw his substantial intellectual powers into those battles and helped guide the Sibley school through much of the fray. Tony’s graduate studies were focused on the adaptive radiation of 9-primaried oscines. It seems quaint today, but he spent many years obtaining DNA-hybridization comparisons of just 27 bird species. Nevertheless, literally everything he discovered about the relationships of those birds (e.g., the radical observation that South American “emberizids” clustered with tanagers rather than sparrows) has endured the test of time and been confirmed by modern DNA sequencing studies. In the process of his PhD studies, Tony became an expert in what we now call genomics. DNA hybridization compared large segments of bird DNA (the “single-copy” genome) and required a substantial understanding of genomic structure and data analysis. In 1984, Tony finished his PhD and began a series of postdocs, first as a Guyer Fellow at the University of Wisconsin (1985–1986), then as a Rea Fellow at the Carnegie
{"title":"Anthony Hemingway Bledsoe, 1956–2019","authors":"F. Sheldon","doi":"10.1093/auk/ukz074","DOIUrl":"https://doi.org/10.1093/auk/ukz074","url":null,"abstract":"Anthony Hemingway “Tony” Bledsoe died at the age of 62 on September 14, 2019. Tony was an outstanding ornithologist, life-long birdwatcher, and most of all an inspirational teacher of ecology and evolution. He was an Elective Member (1990) of the American Ornithologists’ Union (AOU), Director of the Ornithological Societies of North America (1998–2000), Assistant to the AOU Treasurer (1996–2000), a key organizer of the AOU’s annual meeting in Pittsburgh (1989), and a founding member of the Connecticut Ornithological Association (1983). Tony was born to Carter and Phyllis Bledsoe in Washington, D.C., on October 10, 1956, but grew up on the Main Line of Philadelphia, graduating from Lower Merion High School. As a young natural history enthusiast, he volunteered to work in the collections at the Academy of Natural Sciences of Philadelphia, where he was inspired to “think clearly” about evolutionary issues by Frank Gill and herpetologist Tom Uzzell. Following high school, Tony attended the University of California, Santa Cruz, where he honed his birdwatching and natural history skills. In 1978, he started his PhD studies in the laboratory of Charles Sibley at Yale University. At the time molecular systematics was a small field, and studies using DNA were rare. With huge intellectual curiosity and boyish naiveté, Tony jumped into the program and soon became an expert in all aspects of phylogenetics. At the time, cladistic morphology was in its full glory, and antipathy toward Sibley’s DNA hybridization, which was viewed (inaccurately) as phenetic and thus hopelessly flawed, led to epic philosophical battles. Tony threw his substantial intellectual powers into those battles and helped guide the Sibley school through much of the fray. Tony’s graduate studies were focused on the adaptive radiation of 9-primaried oscines. It seems quaint today, but he spent many years obtaining DNA-hybridization comparisons of just 27 bird species. Nevertheless, literally everything he discovered about the relationships of those birds (e.g., the radical observation that South American “emberizids” clustered with tanagers rather than sparrows) has endured the test of time and been confirmed by modern DNA sequencing studies. In the process of his PhD studies, Tony became an expert in what we now call genomics. DNA hybridization compared large segments of bird DNA (the “single-copy” genome) and required a substantial understanding of genomic structure and data analysis. In 1984, Tony finished his PhD and began a series of postdocs, first as a Guyer Fellow at the University of Wisconsin (1985–1986), then as a Rea Fellow at the Carnegie","PeriodicalId":382448,"journal":{"name":"The Auk","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134138702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Cadena, Andrés M. Cuervo, Laura N. Céspedes, Gustavo A. Bravo, N. Krabbe, T. Schulenberg, G. Derryberry, L. F. Silveira, E. Derryberry, R. T. Brumfield, J. Fjeldså
ABSTRACT We studied the phylogeny, biogeography, and diversification of suboscine passerines in the genus Scytalopus (Rhinocryptidae), a widespread, species-rich, and taxonomically challenging group of Neotropical birds. We analyzed nuclear (exons, regions flanking ultraconserved elements) and mitochondrial (ND2) DNA sequence data for a taxonomically and geographically comprehensive sample of specimens collected from Costa Rica to Patagonia and Brazil. We found that Scytalopus is a monophyletic group sister to Eugralla and consists of 3 main clades roughly distributed in (1) the Southern Andes, (2) eastern Brazil, and (3) the Tropical Andes and Central America. The clades from the Southern Andes and eastern Brazil are sister to each other. Despite their confusing uniformity in plumage coloration, body shape, and overall appearance, rates of species accumulation through time in Scytalopus since the origin of the clade in the Late Miocene are unusually high compared with those of other birds, suggesting rapid non-adaptive diversification in the group. We attribute this to their limited dispersal abilities making them speciation-prone and their occurrence in a complex landscape with numerous barriers promoting allopatric differentiation. Divergence times among species and downturns in species accumulation rates in recent times suggest that most speciation events in Scytalopus predate climatic oscillations of the Pleistocene. Our analyses identified various cases of strong genetic structure within species and lack of monophyly of taxa, flagging populations which likely merit additional study to clarify their taxonomic status. In particular, detailed analyses of species limits are due in S. parvirostris, S. latrans, S. speluncae, the S. atratus complex, and the Southern Andes clade.
摘要/ ABSTRACT摘要:本文研究了新热带鸟类中分布广泛、种类丰富、分类学具有挑战性的类群——长尾鸟属(Rhinocryptidae)亚种雀形目雀形目的系统发育、生物地理和多样性。我们分析了从哥斯达黎加到巴塔哥尼亚和巴西收集的标本的分类和地理综合样本的核(外显子，超保守元件两侧的区域)和线粒体(ND2) DNA序列数据。研究发现，Scytalopus是与Eugralla同属的单系类群，由3个主要分支组成，大致分布于(1)南安第斯山脉，(2)巴西东部，(3)热带安第斯山脉和中美洲。来自南安第斯山脉和巴西东部的分支是姐妹。尽管它们在羽毛颜色、身体形状和整体外观上的一致性令人困惑，但与其他鸟类相比，自晚中新世进化支起源以来，随着时间的推移，Scytalopus的物种积累率异常高，这表明该群体存在快速的非适应性多样化。我们将其归因于它们有限的传播能力，使它们易于形成物种，并且它们出现在一个复杂的景观中，有许多促进异域分化的障碍。物种间的分化时间和近期物种积累率的下降表明，长爪龙的大多数物种形成事件早于更新世的气候振荡。我们的分析发现了多种物种内部强遗传结构和分类群单一性缺乏的情况，标记了可能值得进一步研究以澄清其分类地位的群体。特别地，详细的物种限制分析将在S. parvirostris, S. latrans, S. speluncae, S. atratus复合体和南安第斯进化支中进行。
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