scholarly journals Signals of recent tropical radiations in Cunoniaceae, an iconic family for understanding Southern Hemisphere biogeography

2020 ◽  
Author(s):  
Ricardo A. Segovia ◽  
Andy R. Griffiths ◽  
Diego Arenas ◽  
A. A. Piyali Dias ◽  
Kyle G. Dexter
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Tropical Regions ◽  
Biogeographic History ◽  
Angiosperm Diversification ◽  
The Family ◽  
Tropical Areas ◽  
Recent Species ◽  
Angiosperm Species ◽  
The Tropics

AbstractExtratropical angiosperm diversity is thought to have arisen from lineages that originated in the more diverse tropics, but studies of dispersal between tropical and extratropical environments and their consequences for diversification are rare. In order to understand the evolutionary effects of shifts between the tropics and extratropics, defined here as areas that do versus do not regularly experience freezing temperatures, we studied the biogeographic history and associated diversification patterns of Cunoniaceae. We mapped the distribution of all species in the family and combined this with a newly constructed phylogeny for the family. The family shows a long evolutionary association with both tropical and extratropical environments, the tropics house considerably greater species richness of Cunoniaceae. Indeed, both tropical and extratropical environments appear to have had a similar number of lineages until 12 Ma, after which time the number of lineages in tropical areas increased at a faster rate. In addition, community phylogenetic approaches show that tropical regions have markedly less phylogenetic diversity than expected given their species richness, which is further suggestive of recent species radiations in tropical areas. The Cunoniaceae show an atypical pattern for angiosperms of frequent shifts between tropical and extratropical environments, but despite this, shows a more conventional pattern of higher, although recent, diversification rates in the tropics. Our results support the idea that high angiosperm species richness in the tropics may result from the tropics acting as a cradle of recent angiosperm diversification.

scholarly journals Richness and phylogenetic diversity are affected by space and time in the megadiverse Atlantic Forest of South America

2018 ◽  
Author(s):  
José Thales da Motta Portillo ◽  
Fausto Erritto Barbo ◽  
Josué Anderson Rêgo Azevedo ◽  
Ricardo Jannini Sawaya
Keyword(s):  
Species Richness ◽  
South America ◽  
Atlantic Forest ◽  
Phylogenetic Diversity ◽  
Latitudinal Gradient ◽  
Environmental Gradients ◽  
Negative Relationship ◽  
Latitudinal Gradients ◽  
Tropical Regions ◽  
The Tropics

Understanding variation of species richness along latitudinal gradients, with more species toward the tropics, represents a challenge for ecologists. Species richness also varies according to the available area, with more species in larger regions, with area and latitude posited as major drivers of richness variations. However, species richness does not fully capture the evolutionary history behind those patterns. Phylogenetic diversity can provide insights on the role of time and evolutionary drivers of environmental gradients. We analyzed here the latitudinal gradient of endemic snakes from the Atlantic Forest of South America, a megadiverse and highly threatened portion of the Neotropics. We assessed the effect of area and average clade age on species richness and phylogenetic diversity, testing whether species richness and phylogenetic diversity increase with area availability and in lower latitudes. We found that area can predict species richness, but not phylogenetic diversity. Brazilian southeastern mountain ranges include larger patches of Atlantic Forest and the highest richness levels, but generally harboring snakes from relatively recent clades (neoendemics). There is a negative relationship between species richness and average clade age along the latitudinal gradient, with older clades found mainly in northern portions, increasing phylogenetic diversity at lower latitudes. Different dimensions of diversity, species richness and phylogenetic diversity, are thus affected in different ways by area and time for speciation in the Atlantic Forest, and this may be a trend in highly diverse tropical regions.

scholarly journals Richness and phylogenetic diversity are affected by space and time in the megadiverse Atlantic Forest of South America

2018 ◽  
Author(s):  
José Thales da Motta Portillo ◽  
Fausto Erritto Barbo ◽  
Josué Anderson Rêgo Azevedo ◽  
Ricardo Jannini Sawaya
Keyword(s):  
Species Richness ◽  
South America ◽  
Atlantic Forest ◽  
Phylogenetic Diversity ◽  
Latitudinal Gradient ◽  
Environmental Gradients ◽  
Negative Relationship ◽  
Latitudinal Gradients ◽  
Tropical Regions ◽  
The Tropics

Understanding variation of species richness along latitudinal gradients, with more species toward the tropics, represents a challenge for ecologists. Species richness also varies according to the available area, with more species in larger regions, with area and latitude posited as major drivers of richness variations. However, species richness does not fully capture the evolutionary history behind those patterns. Phylogenetic diversity can provide insights on the role of time and evolutionary drivers of environmental gradients. We analyzed here the latitudinal gradient of endemic snakes from the Atlantic Forest of South America, a megadiverse and highly threatened portion of the Neotropics. We assessed the effect of area and average clade age on species richness and phylogenetic diversity, testing whether species richness and phylogenetic diversity increase with area availability and in lower latitudes. We found that area can predict species richness, but not phylogenetic diversity. Brazilian southeastern mountain ranges include larger patches of Atlantic Forest and the highest richness levels, but generally harboring snakes from relatively recent clades (neoendemics). There is a negative relationship between species richness and average clade age along the latitudinal gradient, with older clades found mainly in northern portions, increasing phylogenetic diversity at lower latitudes. Different dimensions of diversity, species richness and phylogenetic diversity, are thus affected in different ways by area and time for speciation in the Atlantic Forest, and this may be a trend in highly diverse tropical regions.

Metabolic asymmetry and the global diversity of marine predators

Science ◽  
2019 ◽  
Vol 363 (6425) ◽  
pp. eaat4220 ◽  
Author(s):  
John M. Grady ◽  
Brian S. Maitner ◽  
Ara S. Winter ◽  
Kristin Kaschner ◽  
Derek P. Tittensor ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Marine Mammals ◽  
Phylogenetic Diversity ◽  
Latitudinal Gradient ◽  
Latitudinal Gradients ◽  
Competitive Interactions ◽  
Marine Predators ◽  
Theoretical Predictions ◽  
The Tropics

Species richness of marine mammals and birds is highest in cold, temperate seas—a conspicuous exception to the general latitudinal gradient of decreasing diversity from the tropics to the poles. We compiled a comprehensive dataset for 998 species of sharks, fish, reptiles, mammals, and birds to identify and quantify inverse latitudinal gradients in diversity, and derived a theory to explain these patterns. We found that richness, phylogenetic diversity, and abundance of marine predators diverge systematically with thermoregulatory strategy and water temperature, reflecting metabolic differences between endotherms and ectotherms that drive trophic and competitive interactions. Spatial patterns of foraging support theoretical predictions, with total prey consumption by mammals increasing by a factor of 80 from the equator to the poles after controlling for productivity.

scholarly journals Phylogenetic diversity as a window into the evolutionary and biogeographic histories of present-day richness gradients for mammals

2011 ◽  
Vol 366 (1576) ◽  
pp. 2414-2425 ◽  
Author(s):  
T. Jonathan Davies ◽  
Lauren B. Buckley
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Diversity Indices ◽  
Environmental Predictors ◽  
Terrestrial Mammals ◽  
Extinction Rates ◽  
Biogeographic History ◽  
Shared Ancestry ◽  
History Of ◽  
Dispersal Events

Phylogenetic diversity (PD) captures the shared ancestry of species, and is increasingly being recognized as a valuable conservation currency. Regionally, PD frequently covaries closely with species richness; however, variation in speciation and extinction rates and/or the biogeographic history of lineages can result in significant deviation. Locally, these differences may be pronounced. Rapid recent speciation or high temporal turnover of lineages can result in low PD but high richness. In contrast, rare dispersal events, for example, between biomes, can elevate PD but have only small impact on richness. To date, environmental predictors of species richness have been well studied but global models explaining variation in PD are lacking. Here, we contrast the global distribution of PD versus species richness for terrestrial mammals. We show that an environmental model of lineage diversification can predict well the discrepancy in the distribution of these two variables in some places, for example, South America and Africa but not others, such as Southeast Asia. When we have information on multiple diversity indices, conservation efforts directed towards maximizing one currency or another (e.g. species richness versus PD) should also consider the underlying processes that have shaped their distributions.

scholarly journals Phylogenetic support for the Tropical Niche Conservatism Hypothesis despite the absence of a clear latitudinal species richness gradient in Yunnan's woody flora

2014 ◽  
Vol 11 (5) ◽  
pp. 7055-7077 ◽  
Author(s):  
G. Tang ◽  
M. G. Zhang ◽  
C. Liu ◽  
Z. Zhou ◽  
W. Chen ◽  
...  
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Latitudinal Gradient ◽  
Extreme Temperature ◽  
Woody Species ◽  
Niche Conservatism ◽  
The North ◽  
Related Plant ◽  
Species Richness Gradient ◽  
The Tropics

Abstract. The Tropical Niche Conservatism Hypothesis (TCH) tries to explain the generally observed latitudinal gradient of increasing species diversity towards the tropics. To date, few studies have used phylogenetic approaches to assess its validity, even though such methods are especially suited to detect changes in niche structure. We test the TCH using modeled distributions of 1898 woody species in Yunnan Province (southwest China) in combination with a family level phylogeny. Unlike predicted, species richness and phylogenetic diversity did not show a latitudinal gradient, but identified two high diversity zones, one in Northwest and one in South Yunnan. Despite this, the underlying residual phylogenetic diversity showed a clear decline away from the tropics, while the species composition became progressingly more phylogenetically clustered towards the North. These latitudinal changes were strongly associated with more extreme temperature variability and declining precipitation and soil water availability, especially during the dry season. Our results suggests that the climatically more extreme conditions outside the tropics require adaptations for successful colonization, most likely related to the plant hydraulic system, that have been acquired by only a limited number of phylogenetically closely related plant lineages. We emphasize the importance of phylogenetic approaches for testing the TCH.

scholarly journals Slowly but surely: gradual diversification and phenotypic evolution in the hyper-diverse tree fern family Cyatheaceae

2019 ◽  
Vol 125 (1) ◽  
pp. 93-103
Author(s):  
Oriane Loiseau ◽  
Anna Weigand ◽  
Sarah Noben ◽  
Jonathan Rolland ◽  
Daniele Silvestro ◽  
...  
Keyword(s):  
Species Richness ◽  
Taxonomic Diversity ◽  
Tree Fern ◽  
Rates Of Evolution ◽  
Extant Species ◽  
The Family ◽  
History Of ◽  
Rapid Diversification ◽  
The Tropics ◽  
Diverse Groups

Abstract Background and Aims The tremendously unbalanced distribution of species richness across clades in the tree of life is often interpreted as the result of variation in the rates of diversification, which may themselves respond to trait evolution. Even though this is likely a widespread pattern, not all diverse groups of organisms exhibit heterogeneity in their dynamics of diversification. Testing and characterizing the processes driving the evolution of clades with steady rates of diversification over long periods of time are of importance in order to have a full understanding of the build-up of biodiversity through time. Methods We studied the macroevolutionary history of the species-rich tree fern family Cyatheaceae and inferred a time-calibrated phylogeny of the family including extinct and extant species using the recently developed fossilized birth–death method. We tested whether the high diversity of Cyatheaceae is the result of episodes of rapid diversification associated with phenotypic and ecological differentiation or driven by stable but low rates of diversification. We compared the rates of diversification across clades, modelled the evolution of body size and climatic preferences and tested for trait-dependent diversification. Key Results This ancient group diversified at a low and constant rate during its long evolutionary history. Morphological and climatic niche evolution were found to be overall highly conserved, although we detected several shifts in the rates of evolution of climatic preferences, linked to changes in elevation. The diversification of the family occurred gradually, within limited phenotypic and ecological boundaries, and yet resulted in a remarkable species richness. Conclusions Our study indicates that Cyatheaceae is a diverse clade which slowly accumulated morphological, ecological and taxonomic diversity over a long evolutionary period and provides a compelling example of the tropics as a museum of biodiversity.

Hormonal treatments for the synchronisation of oestrus in dairy goats raised in the tropics

2004 ◽  
Vol 16 (4) ◽  
pp. 415 ◽  
Author(s):  
V. J. F. Freitas ◽  
D. Rondina ◽  
E. S. Lopes Júnior ◽  
D. I. A. Teixeira ◽  
N. R. O. Paula
Keyword(s):  
Hormonal Treatment ◽  
Alternative Possibilities ◽  
Milk Supply ◽  
Dairy Goats ◽  
Developing Regions ◽  
Efficient Tool ◽  
Tropical Regions ◽  
Tropical Areas ◽  
The Tropics ◽  
Hormonal Treatments

In tropical areas, local goats are often reported as being able to reproduce throughout the year, whereas an influence of season is found to be a factor when importing different dairy breeds. In these areas, oestrus synchronisation in goats is of interest for both technical (synchronisation of kidding, adjustment to forage availability or to continuous milk supply) and genetic reasons (dissemination of improved genotypes by AI). The use of a progestagen vaginal sponge combined with equine chorionic gonadotrophin (eCG)-cloprostenol injections remains an efficient tool to achieve synchronisation in temperate and tropical zones. However, the oestrus synchronisation treatments currently used for goats in tropical regions were originally developed for goats bred in temperate regions. For this reason, several alternative possibilities for improving the efficiency of the hormonal treatment are evaluated. Oestrus synchronisation with luteolytic agents is efficient (resulting in more than 70% of goats in oestrus) and it takes into account female cyclicity. In developing regions of the tropics, the use of buck teasing appears to be a promising approach to control oestrus and ovulation. The use of this technique provides 60% of females in oestrus within 5 days of introducing the bucks. Considering the availability of nutrients as the ultimate regulator of reproduction in the tropics, the control of nutritional condition is essential before the use of hormonal treatments for oestrus synchronisation in goats bred in these regions takes place.

scholarly journals Large-scale phylogenetic analyses reveal the causes of high tropical amphibian diversity

2013 ◽  
Vol 280 (1770) ◽  
pp. 20131622 ◽  
Author(s):  
R. Alexander Pyron ◽  
John J. Wiens
Keyword(s):  
Species Richness ◽  
Time Scales ◽  
Large Scale ◽  
Phylogenetic Analyses ◽  
Geological Time ◽  
Tropical Regions ◽  
Extinction Rates ◽  
Tropical Diversity ◽  
Limited Dispersal ◽  
The Tropics

Many groups show higher species richness in tropical regions but the underlying causes remain unclear. Despite many competing hypotheses to explain latitudinal diversity gradients, only three processes can directly change species richness across regions: speciation, extinction and dispersal. These processes can be addressed most powerfully using large-scale phylogenetic approaches, but most previous studies have focused on small groups and recent time scales, or did not separate speciation and extinction rates. We investigate the origins of high tropical diversity in amphibians, applying new phylogenetic comparative methods to a tree of 2871 species. Our results show that high tropical diversity is explained by higher speciation in the tropics, higher extinction in temperate regions and limited dispersal out of the tropics compared with colonization of the tropics from temperate regions. These patterns are strongly associated with climate-related variables such as temperature, precipitation and ecosystem energy. Results from models of diversity dependence in speciation rate suggest that temperate clades may have lower carrying capacities and may be more saturated (closer to carrying capacity) than tropical clades. Furthermore, we estimate strikingly low tropical extinction rates over geological time scales, in stark contrast to the dramatic losses of diversity occurring in tropical regions presently.

scholarly journals Malpighiaceae de Colombia: Patrones de distribución, riqueza, endemismo y diversidad filogenética

2021 ◽  
Vol 9 (1) ◽  
pp. 39-54
Author(s):  
Diego Giraldo-Cañas
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
American Continent ◽  
Altitudinal Gradients ◽  
The Andes ◽  
Plant Group ◽  
Wide Range ◽  
The Family ◽  
Relationship Of ◽  
The Relationship

Malpighiaceae constitutes a family of 77 genera and ca. 1300 species, distributed in tropical and subtropical regions of both hemispheres. They are mainly diversified in the American continent and distributed in a wide range of habitats and altitudinal gradients. For this reason, this family can be a model plant group to ecological and biogeographical analyses, as well as evolutive studies. In this context, an analysis of distribution, richness, endemism and phylogenetic diversity of Malpighiaceae in natural regions and their altitudinal gradients was undertaken. Malpighiaceae are represented in Colombia by 34 genera and 246 species (19.1% of endemism). Thus, Colombia and Brazil (44 genera, 584 species, 61% of endemism) are the two richest countries on species of this family. The highest species richness and endemism in Colombia is found in the lowlands (0-500 m a.s.l.: 212 species, 28 endemics); only ten species are distributed on highlands (2500-3200 m a.s.l.). Of the Malpighiaceae species in Colombia, Heteropterys leona and Stigmaphyllon bannisterioides have a disjunct amphi-Atlantic distribution, and six other species show intra-American disjunctions. Both richness and endemism decrease with altitude (y = -0.061x + 173.57; R2 = 0.82; y = -0.009x + 27.76; R2 = 0.95, respectively). Amazonia (116 species, 4 endemics) and the Andes (89 species, 23 endemics) exhibit the highest richness among the family. In Colombia, 15 of the 19 clades among the family are represented, where the most diversified are the Stigmaphyllon clade (5 genera, 48 species, 10 endemics), the Byrsonima clade (3/39/5) and the Hiraea clade (3/31/9). The relationship of phylogenetic diversity with altitude is similar to the pattern of specific richness by altitudinal interval. Amazonia, Orinoquia, and Magdalena Valley show highest phylogenetic diversity. These results, combined with those of other highly diversified biological groups in the country, could be important to define and delimitate new priority areas for conservation in Colombia.

scholarly journals IDENTIFICATION OF MYCOHETEROTROPHIC PLANTS (Burmanniaceae, Orchidaceae, Polygalaceae, Tiuridaceae) IN NORTH SUMATRA, INDONESIA

2020 ◽  
Vol 6 (2) ◽  
pp. 59
Author(s):  
Dina Handayani ◽  
Salwa Rezeqi ◽  
Wina Dyah Puspita Sari ◽  
Yusran Efendi Ritonga ◽  
Hary Prakasa
Keyword(s):  
Nature Reserve ◽  
Humid Forest ◽  
Natural Park ◽  
The Family ◽  
Tropical Areas ◽  
Nature Park ◽  
Mycoheterotrophic Plants ◽  
Resources Conservation ◽  
The Tropics ◽  
North Sumatra

The majority of mycoheterotrophic herbs live in shady and humid forest. Therefore, the types of mycoheterotrophic plant are very abundant in tropical areas. One of the areas in Indonesia with the tropics is North Sumatera province. Unfortunately, the information about the species of mycoheterotrophic in North Sumatra is still limited. The objective of the research was to figure out the types of mycoheterotrophic plants in North Sumatra. The study was conducted in August until October 2019 in several areas of the Natural Resources Conservation Hall (BBKSDA) of North Sumatra province, the nature Reserve and nature Park. The research sites covered Tinggi Raja Nature Reserve, Dolok Sibual-Buali Nature Reserve, Sibolangit Tourist Park and Sicike-Cike Natural Park. In conducting sampling, the method used was through exploration or cruising method. The list of mycoheterotrophic plant species presented in this study consisted of their scientific names, synonyms, descriptions, distributions, and ecological information. A total of 9 species of mycoheterotrophic plants (4 families) in Sumatra have been found. As for the family Burmanniaceae, there are three species Burmannia championii, Burmannia lutescens, Gymnosiphon aphyllus. On the other hand, as for the Orchidaceae, there are 4 species, such as Didymoplexis pallens, Eulophia zollingeri, Galeola lindleyana, Gastrodia verrucosa while for the Poligalaceae and Tiuridaceae family, simply one type is found: Epirixanthes elongata and Sciaphila Secundiflora, respectively.

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