The tropics: cradle, museum or casino? A dynamic null model for latitudinal gradients of species diversity

2008 ◽  
Vol 11 (7) ◽  
pp. 653-663 ◽  
Author(s):  
Héctor T. Arita ◽  
Ella Vázquez-Domínguez
2015 ◽  
Vol 282 (1819) ◽  
pp. 20151589 ◽  
Author(s):  
Alyssa R. Cirtwill ◽  
Daniel B. Stouffer ◽  
Tamara N. Romanuk

Several properties of food webs—the networks of feeding links between species—are known to vary systematically with the species richness of the underlying community. Under the ‘latitude–niche breadth hypothesis’, which predicts that species in the tropics will tend to evolve narrower niches, one might expect that these scaling relationships could also be affected by latitude. To test this hypothesis, we analysed the scaling relationships between species richness and average generality, vulnerability and links per species across a set of 196 empirical food webs. In estuarine, marine and terrestrial food webs there was no effect of latitude on any scaling relationship, suggesting constant niche breadth in these habitats. In freshwater communities, on the other hand, there were strong effects of latitude on scaling relationships, supporting the latitude–niche breadth hypothesis. These contrasting findings indicate that it may be more important to account for habitat than latitude when exploring gradients in food-web structure.


2019 ◽  
Vol 7 (8) ◽  
pp. 243
Author(s):  
Eduard A. Titlyanov ◽  
Tamara V. Titlyanova ◽  
Anna V. Scriptsova ◽  
Yuxiao Ren ◽  
Xiubao Li ◽  
...  

Intensive algal sampling conducted in 2016–2019 in the Xiaodong Hai locality (Hainan Island, South China Sea), yielded a total of 198 benthic macroalgal species and their taxonomic forms (54% reds, 20% browns and 26% greens) and 20 species of Cyanobacteria. The largest number of species belonged to the families Rhodomelaceae, Ceramiaceae and Corallinaceae (Rhodophyta); Sargassaceae and Dictyotaceae (Phaeophyceae); Cladophoraceae and Caulerpaceae (Chlorophyta). The majority (79%) of species inhabiting only the tropics or subtropics were previously recorded and 21% of the species were also inhabiting temperate latitudes. Cosmopolitan algae inhabiting from the tropics to Arctic or Antarctic waters amounted to 14%. The level of maximum similarity of macroalgal species diversity in different years was on average more than 70%, interannual species specificity was observed only in the group of dominating species in algal turf communities. The seasonal variability of floras was manifested in a significant decrease in species diversity from the dry season to the rainy and in the change of dominant species in algal turf communities.


Cladistics ◽  
2002 ◽  
Vol 18 (5) ◽  
pp. 537-538
Author(s):  
E PIANKA
Keyword(s):  

Science ◽  
2019 ◽  
Vol 363 (6425) ◽  
pp. eaat4220 ◽  
Author(s):  
John M. Grady ◽  
Brian S. Maitner ◽  
Ara S. Winter ◽  
Kristin Kaschner ◽  
Derek P. Tittensor ◽  
...  

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.


2013 ◽  
Vol 9 (6) ◽  
pp. 20130778 ◽  
Author(s):  
Márcio S. Araújo ◽  
Raul Costa-Pereira

The increase in the number of species with decreasing latitude is a striking pattern of global biodiversity. An important feature of studies of this pattern up to now has been the focus on species as the fundamental unit of interest, neglecting potential within-species ecological diversity. Here, we took a new perspective on this topic by measuring the degree to which individuals within populations differ in niche attributes across a latitudinal gradient (range: 54.01° S to 69.12° N). We show that 156 populations of 76 species across a wide range of vertebrate and invertebrate animal taxa contain more ecologically diverse assemblages of individuals towards lower latitudes. Our results add a new level of complexity to our understanding of global patterns of biodiversity and suggest the possibility that niche variation is partly responsible for the latitudinal gradients of species diversity.


Author(s):  
Christopher J. Freeman ◽  
Cole G. Easson ◽  
David M. Baker

Many species of marine sponges on tropical reefs host abundant and diverse symbiont communities capable of varied metabolic pathways. While such communities may confer a nutritional benefit to some hosts (termed High Microbial Abundance (HMA) sponges), other sympatric species host only sparse symbiont communities (termed Low Microbial Abundance (LMA) sponges) and obtain a majority of their C and N from local sources. Sponge communities are widespread across large latitudinal gradients, however, and recent evidence suggests that these symbioses may also extend beyond the tropics. We investigated the role that symbionts play in the ecology of sponges from the temperate, hard-bottom reefs of Gray's Reef National Marine Sanctuary by calculating the niche size (as standard ellipse area (SEAc)) and assessing the relative placement of five HMA and four LMA sponge species within bivariate (δ13C and δ15N) isotopic space. Although photosymbiont abundance was low across most of these species, sponges were widespread across isotopic niche space, implying that microbial metabolism confers an ecological benefit to temperate sponges by expanding host metabolic capability. To examine how these associations vary across a latitudinal gradient, we also compared the relative placement of temperate and tropical conspecifics within isotopic space. Surprisingly, shifts in sponge δ13C and δ15N values between these regions suggest a reduced reliance on symbiont-derived nutrients in temperate sponges compared with their tropical conspecifics. Despite this, symbiotic sponges in temperate systems likely have a competitive advantage, allowing them to grow and compete for space within these habitats.


2020 ◽  
Author(s):  
J. Drury ◽  
J. Clavel ◽  
J.A. Tobias ◽  
J. Rolland ◽  
C. Sheard ◽  
...  

AbstractThe latitudinal diversity gradient is one of the most striking patterns in nature yet its implications for morphological evolution are poorly understood. In particular, it has been proposed that an increased intensity of species interactions in tropical biota may either promote or constrain trait evolution, but which of these outcomes predominates remains uncertain. Here, we develop tools for fitting phylogenetic models of phenotypic evolution in which the impact of species interactions can vary across lineages. Deploying these models on a global avian trait dataset to explore differences in trait divergence between tropical and temperate lineages, we find that the effect of latitude on the mode and tempo of morphological evolution is weak and clade- or trait-dependent. Our results indicate that species interactions do not disproportionately impact morphological evolution in tropical bird families and question the validity and universality of previously reported patterns of slower trait evolution in the tropics.


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