scholarly journals Genomic phylogeography of the White-crowned Manakin Pseudopipra pipra (Aves: Pipridae) illuminates a continental-scale radiation out of the Andes

2019 ◽  
Author(s):  
Jacob S. Berv ◽  
Leonardo Campagna ◽  
Teresa J. Feo ◽  
Ivandy Castro-Astor ◽  
Camila C. Ribas ◽  
...  

AbstractThe complex landscape history of the Neotropics has generated opportunities for population isolation and subsequent diversification that place this region among the most species-rich in the world. Detailed phylogeographic studies are required to uncover the biogeographic histories of Neotropical taxa, to identify evolutionary correlates of diversity, and to reveal patterns of genetic connectivity, disjunction, and potential differentiation among lineages from different areas of endemism. The White-crowned Manakin (Pseudopipra pipra) is a small suboscine passerine bird that is broadly distributed through the subtropical rainforests of Central America, the lower montane cloud forests of the Andes from Colombia to central Peru, the lowlands of Amazonia and the Guianas, and the Atlantic forest of southeast Brazil. Pseudopipra is currently recognized as a single, polytypic biological species. We studied the effect of the Neotropical landscape on genetic and phenotypic differentiation within this species using genomic data derived from double digest restriction site associated DNA sequencing (ddRAD), and mitochondrial DNA. Most of the genetic breakpoints we identify among populations coincide with physical barriers to gene flow previously associated with avian areas of endemism. The phylogenetic relationships among these populations imply a novel pattern of Andean origination for this group, with subsequent diversification into the Amazonian lowlands. Our analysis of genomic admixture and gene flow establishes a complex history of introgression between some western Amazonian populations. These reticulate processes confound our application of standard concatenated and coalescent phylogenetic methods and raise the question of whether a lineage in the western Napo area of endemism should be considered a hybrid species. Lastly, analysis of variation in vocal and plumage phenotypes in the context of our phylogeny supports the hypothesis that Pseudopipra is a species-complex composed of at least 8, and perhaps up to 17 distinct species which have arisen in the last ∼2.5 Ma.

2019 ◽  
Vol 110 (5) ◽  
pp. 587-600
Author(s):  
A Millie Burrell ◽  
Jeffrey H R Goddard ◽  
Paul J Greer ◽  
Ryan J Williams ◽  
Alan E Pepper

Abstract Globally, a small number of plants have adapted to terrestrial outcroppings of serpentine geology, which are characterized by soils with low levels of essential mineral nutrients (N, P, K, Ca, Mo) and toxic levels of heavy metals (Ni, Cr, Co). Paradoxically, many of these plants are restricted to this harsh environment. Caulanthus ampexlicaulis var. barbarae (Brassicaceae) is a rare annual plant that is strictly endemic to a small set of isolated serpentine outcrops in the coastal mountains of central California. The goals of the work presented here were to 1) determine the patterns of genetic connectivity among all known populations of C. ampexlicaulis var. barbarae, and 2) estimate contemporary effective population sizes (Ne), to inform ongoing genomic analyses of the evolutionary history of this taxon, and to provide a foundation upon which to model its future evolutionary potential and long-term viability in a changing environment. Eleven populations of this taxon were sampled, and population-genetic parameters were estimated using 11 nuclear microsatellite markers. Contemporary effective population sizes were estimated using multiple methods and found to be strikingly small (typically Ne < 10). Further, our data showed that a substantial component of genetic connectivity of this taxon is not at equilibrium, and instead showed sporadic gene flow. Several lines of evidence indicate that gene flow between isolated populations is maintained through long-distance seed dispersal (e.g., >1 km), possibly via zoochory.


2021 ◽  
Vol 12 ◽  
Author(s):  
Alison G. Nazareno ◽  
L. Lacey Knowles ◽  
Christopher W. Dick ◽  
Lúcia G. Lohmann

Seed dispersal is crucial to gene flow among plant populations. Although the effects of geographic distance and barriers to gene flow are well studied in many systems, it is unclear how seed dispersal mediates gene flow in conjunction with interacting effects of geographic distance and barriers. To test whether distinct seed dispersal modes (i.e., hydrochory, anemochory, and zoochory) have a consistent effect on the level of genetic connectivity (i.e., gene flow) among populations of riverine plant species, we used unlinked single-nucleotide polymorphisms (SNPs) for eight co-distributed plant species sampled across the Rio Branco, a putative biogeographic barrier in the Amazon basin. We found that animal-dispersed plant species exhibited higher levels of genetic diversity and lack of inbreeding as a result of the stronger genetic connectivity than plant species whose seeds are dispersed by water or wind. Interestingly, our results also indicated that the Rio Branco facilitates gene dispersal for all plant species analyzed, irrespective of their mode of dispersal. Even at a small spatial scale, our findings suggest that ecology rather than geography play a key role in shaping the evolutionary history of plants in the Amazon basin. These results may help improve conservation and management policies in Amazonian riparian forests, where degradation and deforestation rates are high.


2020 ◽  
Author(s):  
Lydian Boschman ◽  
Mauricio Bermúdez ◽  
Fabien Condamine

<p>The Andes are the longest continental mountain range on Earth, stretching from tropical Colombia and Venezuela in the north to temperate to sub-polar Patagonia in the south along the western margin of the South American continent. Biological diversity is extraordinarily high, especially in the northern tropical Andes, which are considered to be the richest biodiversity hotspot in the world. The Andes are relatively young; a large part of the modern topography is the result of surface uplift that occurred during and since the Miocene. However, large differences exist in the timing of shortening, exhumation, and surface uplift between the northern, central, and southern Andes, as well as between the various parallel Cordilleras. Mountain building directly links to climate dynamics, the development of drainage patterns, and the evolution of biomes and biodiversity. Therefore, determining the timing of surface uplift for each of the different Andean regions is of crucial importance for our understanding of continental-scale moisture transport and atmospheric circulation, the origin and evolution of the Amazon River and Rainforest, and ultimately, the origin and evolution of species in South America.</p><p>Determining surface elevations through geological time is not straightforward because the geological record does not contain a direct measure of topography. Commonly used methods to indirectly estimate paleo-elevation include low temperature thermochronology, palynology/paleobotany, the identification and dating of paleosurfaces, and analyzing the stratigraphic record of foreland basins that quantitatively record the topographic and erosional history of an adjacent mountain range. Additionally, paleo-elevation can be estimated more directly by stable isotope paleo-altimetry: atmospheric δ<sup>18</sup>O and δD vary with elevation as precipitation from ascending air parcels along an orographic barrier removes the heavy isotopes. The δ<sup>18</sup>O and δD values in authigenic/pedogenic materials (paleosols or lakes), biogenic archives (e.g. fossil teeth), volcanic glass, or organic biomarkers (e.g. leaf-wax n-alkanes preserved in soils or sediments) may thus record paleo-elevation.</p><p>In this study, we present a compilation of (direct and indirect) estimates of paleo-elevation of the Andes. We generate a reconstruction of surface uplift, per latitudinal sector of the Andes and per Cordillera or range, containing elevation values per 1x1 degree cell and per Myr. We discuss the areas and/or times where this reconstruction is uncertain as a result of either a lack of data, or a discrepancy between different data sets. Next, we present a compilation of low temperature thermochronology data, and compare the paleo-elevation history of the Andes with its exhumation history. We analyze spatial and temporal variations in erosion rates during Andean mountain building. Last, we use the paleo-elevation reconstruction to analyze the role of Andean mountain building in the rates of species diversification for hummingbirds (clade of Brilliants and Coquettes), iguanians (Liolaemus), tree frogs (two families), and flowering plants (centropogonids and orchids). We use a model‐testing approach that compares various diversification scenarios including a series of biologically realistic models to estimate speciation and extinction rates using a phylogeny, while assessing the relationship between diversification and environmental variables.</p>


2019 ◽  
Vol 97 (3) ◽  
pp. 267-279 ◽  
Author(s):  
Cori L. Lausen ◽  
Michael Proctor ◽  
David W. Nagorsen ◽  
Doug Burles ◽  
David Paetkau ◽  
...  

Recognizing delineations of gene flow among groups of animals can be challenging but is necessary for conservation and management. Of particular importance is the identification of species boundaries. Several physical and genetic traits have been used with mixed success to distinguish Myotis keenii (Merriam, 1895) (Keen’s myotis) and Myotis evotis (H. Allen, 1864) (long-eared myotis), but it is unclear whether species distinction is biologically warranted. We generated 12–14 microsatellite locus genotypes for 275 long-eared Myotis representing four species — M. keenii, M. evotis, Myotis septentrionalis (Trouessart, 1897) (northern myotis), and Myotis thysanodes Miller, 1897 (fringed myotis) — from across northwestern North America and 23 Myotis lucifugus (Le Conte, 1831) (little brown myotis) as the outgroup. Population genetic analyses revealed four well-defined groups (species): M. septentrionalis, M. thysanodes, M. lucifugus, and a single group comprising M. keenii and M. evotis. We document high rates of gene flow within M. evotis/M. keenii. Cytochrome b gene (mtDNA) sequencing failed to resolve morphologically identifiable species. We highlight the importance of geographically thorough investigation of genetic connectivity (nuclear markers) when assessing taxonomic status of closely related groups. We document a morphometric cline within M. evotis/M. keenii that may in part explain earlier analyses that led to the description of the smaller bodied M. keenii (type locality: Haida Gwaii). We conclude that M. keenii does not qualify as a genetic or biological species.


The Auk ◽  
2019 ◽  
Vol 136 (2) ◽  
Author(s):  
Kevin Winker ◽  
Travis C Glenn ◽  
Jack Withrow ◽  
Spencer G Sealy ◽  
Brant C Faircloth

Abstract New study systems and tools are needed to understand how divergence and speciation occur between lineages with gene flow. Migratory birds often exhibit divergence despite seasonal migration, which brings populations into contact with one another. We studied divergence between 2 subspecies of Northern Saw-whet Owl (Aegolius acadicus), in which a sedentary population on the islands of Haida Gwaii, British Columbia (A. a. brooksi), exists in the presence of the other form (A. a. acadicus) during migration but not during the breeding season. Prior research showed fixed mtDNA divergence but left open the question of nuclear gene flow. We used 2,517 ultraconserved element loci to examine the demographic history of this young taxon pair. Although we did not observe fixed single nucleotide polymorphism differences between populations among our genotyped individuals, 100% of the birds were diagnosable and δaδI analyses suggested the demographic model best fitting the data was one of split-bidirectional-migration (i.e. speciation with gene flow). We dated the split between brooksi and acadicus to ~278 Kya, and our analyses suggested gene flow between groups was skewed, with ~0.7 individuals per generation coming from acadicus into brooksi and ~4.4 going the opposite direction. Coupled with an absence of evidence of phenotypic hybrids and the birds’ natural history, these data suggest brooksi may be a young biological species arising despite historic gene flow.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.


2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Fan Jiang ◽  
Ruiyi Lin ◽  
Changyi Xiao ◽  
Tanghui Xie ◽  
Yaoxin Jiang ◽  
...  

Abstract Background The most prolific duck genetic resource in the world is located in Southeast/South Asia but little is known about the domestication and complex histories of these duck populations. Results Based on whole-genome resequencing data of 78 ducks (Anas platyrhynchos) and 31 published whole-genome duck sequences, we detected three geographic distinct genetic groups, including local Chinese, wild, and local Southeast/South Asian populations. We inferred the demographic history of these duck populations with different geographical distributions and found that the Chinese and Southeast/South Asian ducks shared similar demographic features. The Chinese domestic ducks experienced the strongest population bottleneck caused by domestication and the last glacial maximum (LGM) period, whereas the Chinese wild ducks experienced a relatively weak bottleneck caused by domestication only. Furthermore, the bottleneck was more severe in the local Southeast/South Asian populations than in the local Chinese populations, which resulted in a smaller effective population size for the former (7100–11,900). We show that extensive gene flow has occurred between the Southeast/South Asian and Chinese populations, and between the Southeast Asian and South Asian populations. Prolonged gene flow was detected between the Guangxi population from China and its neighboring Southeast/South Asian populations. In addition, based on multiple statistical approaches, we identified a genomic region that included three genes (PNPLA8, THAP5, and DNAJB9) on duck chromosome 1 with a high probability of gene flow between the Guangxi and Southeast/South Asian populations. Finally, we detected strong signatures of selection in genes that are involved in signaling pathways of the nervous system development (e.g., ADCYAP1R1 and PDC) and in genes that are associated with morphological traits such as cell growth (e.g., IGF1R). Conclusions Our findings provide valuable information for a better understanding of the domestication and demographic history of the duck, and of the gene flow between local duck populations from Southeast/South Asia and China.


Heredity ◽  
2021 ◽  
Author(s):  
Yael S. Rodger ◽  
Alexandra Pavlova ◽  
Steve Sinclair ◽  
Melinda Pickup ◽  
Paul Sunnucks

AbstractConservation management can be aided by knowledge of genetic diversity and evolutionary history, so that ecological and evolutionary processes can be preserved. The Button Wrinklewort daisy (Rutidosis leptorrhynchoides) was a common component of grassy ecosystems in south-eastern Australia. It is now endangered due to extensive habitat loss and the impacts of livestock grazing, and is currently restricted to a few small populations in two regions >500 km apart, one in Victoria, the other in the Australian Capital Territory and nearby New South Wales (ACT/NSW). Using a genome-wide SNP dataset, we assessed patterns of genetic structure and genetic differentiation of 12 natural diploid populations. We estimated intrapopulation genetic diversity to scope sources for genetic management. Bayesian clustering and principal coordinate analyses showed strong population genetic differentiation between the two regions, and substantial substructure within ACT/NSW. A coalescent tree-building approach implemented in SNAPP indicated evolutionary divergence between the two distant regions. Among the populations screened, the last two known remaining Victorian populations had the highest genetic diversity, despite having among the lowest recent census sizes. A maximum likelihood population tree method implemented in TreeMix suggested little or no recent gene flow except potentially between very close neighbours. Populations that were more genetically distinctive had lower genetic diversity, suggesting that drift in isolation is likely driving population differentiation though loss of diversity, hence re-establishing gene flow among them is desirable. These results provide background knowledge for evidence-based conservation and support genetic rescue within and between regions to elevate genetic diversity and alleviate inbreeding.


Sign in / Sign up

Export Citation Format

Share Document