scholarly journals Macroevolutionary pattern of Saussurea (Asteraceae) provides insights into the drivers of radiating diversification

2021 ◽  
Vol 288 (1962) ◽  
Author(s):  
Xu Zhang ◽  
Jacob B. Landis ◽  
Yanxia Sun ◽  
Huajie Zhang ◽  
Nan Lin ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Evolutionary Dynamics ◽  
Niche Breadth ◽  
Morphological Evolution ◽  
Distribution Data ◽  
Ecological Distribution ◽  
Rapid Radiation ◽  
Diversification Rates ◽  
Intrinsic Factors ◽  
Evolutionary Radiations

Evolutionary radiations have intrigued biologists for more than a century, yet our understanding of the drivers of radiating diversification is still limited. We investigate the roles of environmental and species-intrinsic factors in driving the rapid radiation of Saussurea (Asteraceae) by deploying a number of palaeoenvironment-, diversity- and trait-dependent models, as well as ecological distribution data. We show that three main clades of Saussurea began to diversify in the Miocene almost simultaneously, with increasing diversification rates (DRs) negatively dependent on palaeotemperature but not dependent on species diversity. Our trait-dependent models detect some adaptive morphological innovations associated with DR shifts, while indicating additional unobserved traits are also likely driving diversification. Accounting for ecological niche data, we further reveal that accelerations in DRs are correlated with niche breadth and the size of species' range. Our results point out a macroevolutionary scenario where both adaptive morphological evolution and ecological opportunities provided by palaeoenvironmental fluctuations triggered an exceptionally radiating diversification. Our study highlights the importance of integrating phylogenomic, morphological, ecological and model-based approaches to illustrate evolutionary dynamics of lineages in biodiversity hotspots.

scholarly journals Insights into the drivers of radiating diversification in biodiversity hotspots using Saussurea (Asteraceae) as a case

2021 ◽  
Author(s):  
Xu Zhang ◽  
Jacob B. Landis ◽  
Yanxia Sun ◽  
Huajie Zhang ◽  
Tao Feng ◽  
...  
Keyword(s):  
Tibet Plateau ◽  
Ecological Niches ◽  
Distribution Data ◽  
List Type ◽  
Adaptive Traits ◽  
Rapid Radiation ◽  
Diversification Rates ◽  
Intrinsic Factors ◽  
High Degree ◽  
Qinghai Tibet Plateau

AbstractThe Qinghai-Tibet Plateau (QTP) encompasses areas with a remarkably high degree of biodiversity, harboring exceptional species-rich radiations. How these radiations formed by interacting with geology, climate and ecology remains seldom examined.We investigate the roles of abiotic (environmental) and biotic (species-intrinsic) factors in driving radiating diversification of Saussurea (Asteraceae) by deploying a number of time-dependent, paleoenvironment-dependent and trait-dependent models, as well as ecological distribution data.We show that three main clades of Saussurea begin to diversify in the Miocene almost simultaneously, with increasing diversification rates toward the present and negative dependence to paleotemperature. Acceleration in diversification rates are correlated with adaptive traits, as well climate lability, niche breadth and species range.We conclude that fluctuation of paleoclimate along with complex QTP environments provided opportunities for increased diversification rates of Saussurea with diverse adaptive traits, highlighting the importance of combinations of clade-specific traits and ecological niches in driving rapid radiation.

scholarly journals Dynamical analysis of the global elevational diversity gradient in passerine birds reveals a prominent role for highlands as species pumps

2020 ◽  
Author(s):  
Paul van Els ◽  
Leonel Herrera-Alsina ◽  
Alex L. Pigot ◽  
Rampal Etienne
Keyword(s):  
Evolutionary Dynamics ◽  
Strong Support ◽  
High Elevation ◽  
Dynamical Analysis ◽  
Reverse Direction ◽  
Passerine Birds ◽  
Diversification Rates ◽  
Diversity Gradient ◽  
As Species ◽  
Almost All

Abstract Low elevation regions harbor the majority of the world’s species diversity compared to high elevation areas. This global elevational diversity gradient, suggests that lowland species have had more time to diversify, or that net diversification rates have been higher in the lowlands (either due to higher ecological limits or intrinsically higher diversification rates). However, highlands seem to be cradles of diversity as they contain many young endemics, suggesting that their rates of speciation are exceptionally fast. Here, we use a phylogenetic diversification model that accounts for the dispersal of species between different elevations to examine the evolutionary dynamics of the elevational diversity gradient in passerine birds, a group that has radiated globally to occupy almost all elevations and latitudes. We find strong support for a model where passerines diversify at the same rate in the highlands and the lowlands but where the rate of dispersal from high to low elevations is more than twice as fast as in the reverse direction. This suggests that while there is no consistent trend in diversification across elevations, highland regions act as species pumps because the diversity they generate migrates into the lowlands, thus setting up the observed gradient in passerine diversity. This species pump is particularly strong in the tropics, where the inferred rate of speciation is 1.4 times faster than in the temperate zone. We conclude that despite their lower diversity, highland regions are disproportionally important for maintaining diversity in the adjacent lowlands. The extinction of species in the tropical highlands due to rapid climate change this century could thus have major and long-lasting impacts on global passerine diversity.

Environmental Damage and its Impacts on Inequality and Poverty: Applications to Brazil and Costa Rica

2007 ◽  
pp. 68
Author(s):  
Mariano Torras
Keyword(s):  
Sensitivity Analysis ◽  
Costa Rica ◽  
Environmental Damage ◽  
Distribution Data ◽  
Ecological Distribution ◽  
Poverty Measures ◽  
Damage Estimates

Accounting for environmental damage is relevant to how one measures the extent and severity of inequality and poverty, and the question of ecological distribution - how the costs associated with environmental damage are distributed across the population - is critical. Following Khan’s (1997) study on Bangladesh, I use environmental damage estimates to adjust inequality and poverty measures for Brazil and Costa Rica. Unlike Khan, I test for different assumptions regarding the ecological distribution. Provisional results indicate that inequality and poverty are understated, and that, under certain assumptions, both worsened in Costa Rica during the 1980s, contrary to what conventional statistics suggest. Want of reliable ecological distribution data, however, suggests that sensitivity analysis around competing assumptions may be preferable to conventional indicators.

scholarly journals Rates of ecological divergence and body size evolution are correlated with species diversification in scaly tree ferns

2016 ◽  
Vol 283 (1834) ◽  
pp. 20161098 ◽  
Author(s):  
Santiago Ramírez-Barahona ◽  
Josué Barrera-Redondo ◽  
Luis E. Eguiarte
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Ecological Niche ◽  
Morphological Evolution ◽  
Ecological Niches ◽  
Species Diversification ◽  
Tree Ferns ◽  
Size Evolution ◽  
Body Sizes ◽  
Body Size Evolution

Variation in species richness across regions and between different groups of organisms is a major feature of evolution. Several factors have been proposed to explain these differences, including heterogeneity in the rates of species diversification and the age of clades. It has been frequently assumed that rapid rates of diversification are coupled to high rates of ecological and morphological evolution, leading to a prediction that remains poorly explored for most species: the positive association between ecological niche divergence, morphological evolution and species diversification. We combined a time-calibrated phylogeny with distribution, ecological and body size data for scaly tree ferns (Cyatheaceae) to test whether rates of species diversification are predicted by the rates at which clades have evolved distinct ecological niches and body sizes. We found that rates of species diversification are positively correlated with rates of ecological and morphological evolution, with rapidly diversifying clades also showing rapidly evolving ecological niches and body sizes. Our results show that rapid diversification of scaly tree ferns is associated with the evolution of species with comparable morphologies that diversified into similar, yet distinct, environments. This suggests parallel evolutionary pathways opening in different tropical regions whenever ecological and geographical opportunities arise. Accordingly, rates of ecological niche and body size evolution are relevant to explain the current patterns of species richness in this ‘ancient’ fern lineage across the tropics.

scholarly journals Modelling the potential ecological niche of domesticated buckwheat in China: archaeological evidence, environmental constraints and climate change

2021 ◽  
Author(s):  
Marta Krzyzanska ◽  
Harriet V. Hunt ◽  
Enrico R. Crema ◽  
Martin K. Jones
Keyword(s):  
Ecological Niche ◽  
Species Distribution Model ◽  
Modern China ◽  
Distribution Model ◽  
Distribution Data ◽  
Environmental Niche ◽  
Dispersal Pattern ◽  
Present Distribution ◽  
Potential Area ◽  
Over Time

AbstractWe present a species distribution model (SDM) of Fagopyrum esculentum (buckwheat) in China using present distribution data and estimates for the past based on palaeoclimatic reconstructions. Our model estimates the potential area suitable for buckwheat cultivation over the last 8,000 years, with northeast China consistently showing the highest suitability, providing insights on the discrepancy between the location of the earliest archaeobotanical records in the area and its origins in southwest China based on biogeographic and genetic data. The model suggests little to no variation over time in the spatial extent of the potential area suitable for buckwheat cultivation. In the northern parts of China, the limits of the ecological niche largely fall within the borders of the study area, while to the west it never extends into the main Tibetan plateau, explaining the lack of fossil evidence from Central Asia. In the southwest, the niche overlaps with the borders of modern China, which supports this direction as a viable route of westward dispersal. The comparison between the prediction from the model and sites with archaeobotanical evidence for Fagopyrum indicates that the environmental niche it occupied remained stable over time. This may contrast with a dispersal pattern characterised by continuous adaptations to new environments facilitated by human activity, which may be suggested for other major and minor crops.

scholarly journals Spatial Modelling of Common Chimpanzees’ (Pan troglodytes schweinifurthii) Ecological Niche in the Western Part of Rwanda

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
J Tuyishimire ◽  
P Nsengiyumva ◽  
G Rwanyiziri ◽  
M Mugabowindekwe
Keyword(s):  
Pan Troglodytes ◽  
National Park ◽  
Ecological Niche ◽  
Spatial Modelling ◽  
Distribution Data ◽  
Location Data ◽  
Western Province ◽  
High Precipitation ◽  
Forest Parks ◽  
Common Chimpanzee

The Western Part of Rwanda is a mountainous region that hosts two important forest parks namely the Nyungwe National Park (NNP) and Gishwati-Mukura National Park (GMNP). The two parks which are located in the Albertine Rift region are known for their high endemism and harbour several endangered plant and animal species, including particularly the Common Chimpanzees (Pan troglodytes schweinifurthii). However, these forests are facing threats including mainly habitat loss, aggravated by climate change both of which are continuously having direct and indirect effects to the Chimpanzees. While conservation of chimpanzees appears critical, there is a need to deeply understand the dynamics of their habitat. This study aimed at modelling the ecological niche of common chimpanzee by integrating species distribution data and environmental layers. Species location data collected in both NNP and GMNP were integrated with environmental variables (temperature, precipitation, altitude, and land cover) through Maximum Entropy (MaxEnt), and Generic Algorithm for Rule-based Prediction (GARP) Models. The results of both models showed that chimpanzees prefer the Southern and the Northern parts of the study area (0.5 < p < 0.87), which is characterised by high altitude, low temperature, and intensive rainfall. It was also noted that MaxEnt predictions were more accurate compared to the GARP’s. MaxEnt predictions showed that 35% (2058.61 ha) of the Western Province are suitable for chimpanzees, while GARP predicted that only 24% (1411.62 ha) are suitable. Furthermore, the study found that the high precipitation, annual and maximum precipitations, and food availability are the most determinants of chimpanzees' habitat. The land use in the Western Province has made the central part less suitable to chimpanzees and therefore, this study recommends that special efforts for the conservation of Common chimpanzees in Rwanda should be concentrated in the Southern Part (around NNP) Nyungwe National Park (main forest and Cyamudongo fragment) and the northern Part (around GMNP) Keywords: Spatial Modelling, Common Chimpanzee, Ecological Niche, Nyungwe National Park, Gishwati-Mukura National Park, Rwanda.

scholarly journals Research on The Evolution of High-tech Industry Competitiveness in Beijing-Tianjin-Hebei

2021 ◽  
Vol 248 ◽  
pp. 02023
Author(s):  
LI Yanxia ◽  
Jie Zhang
Keyword(s):  
Ecological Niche ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Evaluation Index System ◽  
Niche Width ◽  
High Tech ◽  
Growth Trend ◽  
High Tech Industry ◽  
Increasing Trend ◽  
Industry Competitiveness

From the perspective of ecological niche, this paper constructs the evaluation index system of the competitiveness of beijing-tianjin-hebei high-tech industry, and analyzes the competitiveness of beijing-tianjin-hebei high-tech industry from the perspectives of niche value, niche width and niche overlap. The results show that :(1) from the perspective of ecological niche, the niche value of the competitiveness of high-tech industries in Beijing, tianjin and hebei does not show an increasing trend with time, and the overall value of the niche is ranked from the largest to the smallest: Beijing, tianjin and hebei.(2) from the niche breadth, beijing-tianjin-hebei high-tech industry competitiveness niche breadth range as follows: 0.26-0.83, Beijing niche width of the widest, hebei niche breadth the narrowest, Beijing and tianjin hi-tech industry competitiveness niche breadth value reduced trend on the whole, hebei niche breadth on overall growth trend.

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