scholarly journals Novel insights into the historical biogeography of the streak-breasted scimitar babbler complex (Aves: Timaliidae: Pomatorhinus ruficollis complex)

2015 ◽  
Vol 61 (5) ◽  
pp. 910-921 ◽  
Author(s):  
Sushma Reddy ◽  
Árpád S. Nyári

Abstract The Streak-breasted Scimitar Babblers of the Pomatorhinus ruficollis species complex are found in most of the forested habitats across southern and eastern Asia. The diversification history of this group is obscured by high plumage variation across populations and conflicting genetic signal across loci. We combined genetic and geographic data from several recent studies to investigate how these species diversified across China using both phylogenetic and ecological niche modeling analyses. These two lines of evidence are consistent in showing that two well-sampled species, P. reconditus and P. nigrostellatus, in central and southern China respectively, likely experienced a history of isolation and expansion as suitable habitat contracted during the last interglacial and expanded in patchy extent during the glacial maximum. The genetic analysis showed that populations of P. nigrostellatus on Hainan Island are very similar to the ones in nearby mainland southern China. We recovered two well-supported clades within P. reconditus that were not geographically structured with both containing individuals from the same localities across central China. This phylogenetic result corresponded to the ecological niche models that showed expansion from refugia since the last interglacial. This study illustrates the value of using an integrative approach and detailed geographic sampling to help understand the recent diversification of birds in China.

Author(s):  
A. Townsend Peterson ◽  
Jorge Soberón ◽  
Richard G. Pearson ◽  
Robert P. Anderson ◽  
Enrique Martínez-Meyer ◽  
...  

This chapter discusses the use of ecological niche modeling to study species invasions, and more specifically to identify and understand genuine exceptions to ecological niche equivalency between native and introduced ranges of species. In addition, it examines the degree to which the geographic course of species’ invasions can be anticipated based on scenopoetic variables and biotic interactions. The chapter also reviews practical considerations that must be taken into account when exploring the utility of ecological niche models in understanding species’ invasions, such as using niche conservatism to predict likely changes in the distributional potential of invasive species under scenarios of changing environmental conditions. Finally, it describes caveats and limitations of the approach and outlines future research directions and challenges involved in the application of niche modeling ideas in species invasions.


2017 ◽  
Vol 16 (2) ◽  
pp. 225 ◽  
Author(s):  
Omar Machado Entiauspe-Neto ◽  
Márcia Ferret Renner ◽  
Conrado Mario-da-Rosa ◽  
Arthur Diesel Abegg ◽  
Daniel Loebmann ◽  
...  

The original description of Elapomorphus wuchereri Günther, 1861 included a drawing and brief comments about the morphology of three specimens; two of the latter belong to another species and the holotype is lost. Based on the discovery of new specimens, we redescribe Elapomorphus wuchereri and designate a neotype. We discuss the variation and the taxonomic history of the species, and based on the results of a species distribution model analysis (SDM), we describe the distribution, extent of occurrence, and conservation status.


2019 ◽  
Vol 116 (26) ◽  
pp. 12895-12900 ◽  
Author(s):  
Erin E. Saupe ◽  
Alexander Farnsworth ◽  
Daniel J. Lunt ◽  
Navjit Sagoo ◽  
Karen V. Pham ◽  
...  

Many higher level avian clades are restricted to Earth’s lower latitudes, leading to historical biogeographic reconstructions favoring a Gondwanan origin of crown birds and numerous deep subclades. However, several such “tropical-restricted” clades (TRCs) are represented by stem-lineage fossils well outside the ranges of their closest living relatives, often on northern continents. To assess the drivers of these geographic disjunctions, we combined ecological niche modeling, paleoclimate models, and the early Cenozoic fossil record to examine the influence of climatic change on avian geographic distributions over the last ∼56 million years. By modeling the distribution of suitable habitable area through time, we illustrate that most Paleogene fossil-bearing localities would have been suitable for occupancy by extant TRC representatives when their stem-lineage fossils were deposited. Potentially suitable habitat for these TRCs is inferred to have become progressively restricted toward the tropics throughout the Cenozoic, culminating in relatively narrow circumtropical distributions in the present day. Our results are consistent with coarse-scale niche conservatism at the clade level and support a scenario whereby climate change over geological timescales has largely dictated the geographic distributions of many major avian clades. The distinctive modern bias toward high avian diversity at tropical latitudes for most hierarchical taxonomic levels may therefore represent a relatively recent phenomenon, overprinting a complex biogeographic history of dramatic geographic range shifts driven by Earth’s changing climate, variable persistence, and intercontinental dispersal. Earth’s current climatic trajectory portends a return to a megathermal state, which may dramatically influence the geographic distributions of many range-restricted extant clades.


Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 649 ◽  
Author(s):  
Emilio Clarke-Crespo ◽  
Claudia N. Moreno-Arzate ◽  
Carlos A. López-González

Ticks are vectors of a large number of pathogens of medical and veterinary importance, and in recent years, they have participated in the rise of multiple infectious outbreaks around the world. Studies have proposed that temperature and precipitation are the main variables that limit the geographical distribution of ticks. The analysis of environmental constraints with ecological niche modeling (ENM) techniques can improve our ability to identify suitable areas for emergence events. Algorithms used in this study showed different distributional patterns for each tick genera; the environmental suitability for Amblyomma includes warm and humid localities below 1000 m above the sea level, while Ixodes is mainly associated with ecosystems with high vegetation cover. Dermacentor and Rhipicephalus genus presented wider distribution patterns; the first includes species that are well adapted to resist desiccation, whereas the latter includes generalist species that are mostly associated with domestic hosts in Mexico. Ecological niche models have proven to be useful in estimating the geographic distribution of many taxa of ticks. Despite our limited knowledge of tick’s diversity, ENM can improve our understanding of the dynamics of vector-borne diseases and can assist public health decision-making processes.


2018 ◽  
Vol 7 (12) ◽  
pp. 2451-2458
Author(s):  
Cordilea Hannah ◽  
Joyce Sudandara Priya ◽  
Kasthuri Bhai N.

Camptothecin (CPT) is one of anticancer drug that is widely used for treating various cancers. In India, the drug is primarily sourced from natural habitats of the red listed species Nothapodytes nimmoniana. Ecological niche models are potential tools to define and predict the “ecological niche” of a species that exhibit ecological variations. The predicted ecological niche of a species indicates their survival fitness against Bioclimatic variables. The habitat suitability was predicted using Maxent for different ecotypes of Nothapodytes nimmoniana (Graham.) Mabb. In this study the synonymised populations of N. nimmoniana in the Western Ghats were cogitated as five different ecotypes. The predicted habitat suitability of different ecotypes were evaluated and correlated against CPT content using high performance thin layer chromatography. The study shows a significant positive correlation between the predicted habitat quality and chemical content. The ecotypes growing in sites predicted as highly suitable showed high content of camptothecin compared to those growing in poorly suitable sites. Thereby enabling precise identification of “chemical hot-spots” which will eventually establish a strong foot hold on monoculture of the species, an effort towards conservation.


Author(s):  
Carrie Wells ◽  
David Tonkyn

Climate change is predicted to alter the geographic distribution of a wide variety of taxa, including butterfly species. Research has focused primarily on high latitude species in North America, with no known studies examining responses of taxa in the southeastern US. The Diana fritillary (Speyeria diana) has experienced a recent range retraction in that region, disappearing from lowland sites and now persisting in two, phylogenetically disjunct mountainous regions. These findings are consistent with the predicted effects of a warming climate on numerous taxa, including other butterfly species in North America and Europe. We used ecological niche modeling to predict future changes to the distribution of S. diana under several climate models. To evaluate how climate change might influence the geographic distribution of this butterfly, we developed ecological niche models using Maxent. We used two global circulation models, CCSM and MIROC, under low and high emissions scenarios to predict the future distribution of S. diana. Models were evaluated using the Receiver Operating Characteristics Area Under Curve test and the True Skill Statistics (mean AUC = 0.91± 0.0028 SE, TSS = 0.87 ± 0.0032 SE for RCP = 4.5, and mean AUC = 0.87± 0.0031SE, TSS = 0.84 ± 0.0032 SE for RCP = 8.5), which both indicate that the models we produced were significantly better than random (0.5). The four modeled climate scenarios resulted in an average loss of 91% of suitable habitat for S. diana by 2050. Populations in the Southern Appalachian Mountains were predicted to suffer the most severe fragmentation and reduction in suitable habitat, threatening an important source of genetic diversity for the species. The geographic and genetic isolation of populations in the west suggest that those populations are equally as vulnerable to decline in the future, warranting ongoing conservation of those populations as well. Our results suggest that the Diana fritillary is under threat of decline by 2050 across its entire distribution from climate change, and is likely to be negatively affected by other human-induced factors as well.


Author(s):  
A. Townsend Peterson ◽  
Jorge Soberón ◽  
Richard G. Pearson ◽  
Robert P. Anderson ◽  
Enrique Martínez-Meyer ◽  
...  

This chapter focuses on the conceptual and applied aspects of environmental data in the context of building and interpreting ecological niche models. It first examines how different suites of environmental factors may affect species distributions across a range of spatial scales before discussing which and how many variables are needed for ecological niche modeling. It then reviews the diverse sources of environmental datasets that are of potential utility in ecological niche modeling and concludes by considering a number of challenges involved in designing and choosing environmental data for ecological niche modeling. These challenges include data preparation, data quality, spatial extent, resolution in space and time, types of environmental data, and ancillary data.


2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Daniel A H Peach ◽  
Benjamin J Matthews

Abstract The coastal rock pool mosquito, Aedes (Tanakius) togoi (Theobald) (Diptera: Culicidae), is found in coastal east Asia in climates ranging from subtropical to subarctic. However, a disjunct population in the Pacific Northwest of North America has an ambiguous heritage. Two potential models explain the presence of Ae. togoi in North America: ancient Beringian dispersal or modern anthropogenic introduction. Genetic studies have thus far proved inconclusive. Here we described the putative ancient distribution of Ae. togoi habitat in east Asia and examined the climatic feasibility of a Beringian introduction into North America using modern distribution records and ecological niche modeling of bioclimatic data from the last interglacial period (~120,000 BP), the last glacial maximum (~21,000 BP), and the mid-Holocene (~6000 BP). Our results suggest that suitable climatic conditions existed for Ae. togoi to arrive in North America through natural dispersal as well as to persist there until present times. Furthermore, we find that ancient distributions of suitable Ae. togoi habitat in east Asia may explain the genetic relationships between Ae. togoi populations identified in other studies. These findings indicate the utility of ecological niche modeling as a complementary tool for studying insect phylogeography.


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