The role of the environmental niche in fostering ecological divergence during adaptive radiation remains enigmatic. In this study, we examine the interplay between environmental niche divergence and conservatism in the context of adaptive radiation on oceanic islands, by characterizing the niche breadth of four Hawaiian arthropod radiations: Tetragnatha spiders (Tetragnathidae Latreille, 1804), Laupala crickets (Gryllidae Otte, 1994), a clade of Drosophila flies (Drosophilidae Fallén, 1823) and Nesosydne planthoppers (Delphacidae Kirkaldy, 1907). We assembled occurrence datasets for the four lineages, modelled their distributions and quantified niche overlap. All four groups occupy the islands in distinct ways, highlighting the contrasting axes of diversification for different lineages. Laupala and Nesosydne have opposite environmental niche extents (broad and narrow, respectively), whereas Tetragnatha and Drosophila share relatively intermediate tolerances. Temperature constrains the distributions of all four radiations. Tests of phylogenetic signal suggest that, for Tetragnatha and Drosophila, closely related species exhibit similar environmental niches; thus, diversification is associated with niche conservatism. Sister species comparisons also show that populations often retain similar environmental tolerances, although exceptions do occur. Results imply that diversification does not occur through ecological speciation; instead, adaptive radiation occurs largely within a single environment.
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This content will become publicly available on October 1, 2025
Climatic niche evolution and speciation modes in the transisthmian Alpheus shrimps (Caridea: Alpheidae)
We studied the niche evolution and diversification modes in transisthmian
Atlantic and Eastern‐Pacific oceans.
We assembled georeferenced occurrences for 33 species of
Our results demonstrate that thermal tolerances, food availability and hydrodynamic forces were relevant environmental axes in evolutionary processes in transisthmian species of
We found evidence that confirms the relevance of the environmental changes that occurred in the West Atlantic and East Pacific for niche evolution in transisthmian
- Award ID(s):
- 1924675
- PAR ID:
- 10559207
- Publisher / Repository:
- Journal of Biogeography
- Date Published:
- Journal Name:
- Journal of Biogeography
- Volume:
- 51
- Issue:
- 10
- ISSN:
- 0305-0270
- Page Range / eLocation ID:
- 1944 to 1957
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Aim There has been considerable interest in niche conservatism, the idea that ecological variables are similar among related species. Much research has focused on climatic niches of recently diverged species, rather than deeper timescales or non‐climatic niche axes. Furthermore, it has been suggested that conservatism disappears over deeper timescales, and is greater in alpha niche traits (like diet and microhabitat) than beta niche variables (like climate). Here, we test these latter two ideas by comparing patterns of phylogenetic conservatism among 10 niche variables across major clades of land vertebrates.
Location Global.
Time Period Present to 350 million years ago.
Major Taxa Studied Tetrapods, including amphibians, mammals, lepidosaurs (including lizards and snakes), turtles, crocodilians and birds.
Methods The 10 niche variables included four alpha niche components (diet, diel activity, habitat, body temperature) and six beta niche components (related to climatic temperature and precipitation). We analysed these variables on time‐calibrated phylogenies with similar taxon sampling (~1700 species), using phylogenetic signal (lambda) to estimate conservatism, along with the
D statistic and estimates of evolutionary rates.Results Phylogenetic signal was generally strong across all variables, with lambda generally >0.80 (with 1.0 representing maximum signal). Nevertheless, mean phylogenetic signal was lower in beta niche traits than alpha niche traits (based on lambda and especially the
D statistic), and alpha niche traits showed significantly slower rates of evolution.Main Conclusions We address two long‐held views in the literature on niche conservatism, rejecting one but supporting the other. We show that phylogenetic signal does not disappear over deep timescales for many important niche variables, even over 350 million years. We also generally support greater conservatism in alpha niche traits than beta niche traits over hundreds of millions of years, a pattern that was previously suggested (but not explicitly tested) based on closely related species.
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Premise The distributions of plant clades are shaped by abiotic and biotic factors as well as historical aspects such as center of origin. Dispersals between distant areas may lead to niche evolution when lineages are established in new environments. Alternatively, dispersing lineages may exhibit niche conservatism, moving between areas with similar environmental conditions. Here we test these contrasting hypotheses in the Datureae clade (Solanaceae).
Methods We used maximum likelihood methods to estimate the ancestral range of Datureae along with the history of biogeographic events. We then characterized the niche of each taxon using climatic and soil variables and tested for shifts in environmental niche optima. Finally, we examined how these shifts relate to the niche breadth of taxa and clades within Datureae and the degree of overlap between them.
Results Datureae originated in the Andes and subsequently expanded its range to North America and non‐Andean regions of South America. The ancestral niche, and that of most
Datura andTrompettia species, is dry, whileBrugmansia species likely shifted toward a more mesic environment. Nonetheless, most Datureae present moderate to high overlap in niche breadth today.Conclusions The expansion of Datureae into North America was associated with niche conservatism, with dispersal into similarly dry areas as occupied by the ancestral lineage. Subsequent niche evolution, including the apparent shift to a mesic niche in
Brugmansia , diversified the range of habitats occupied by species in the tribe Datureae but also led to significant niche overlap among the three genera. -
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Abstract Understanding how the climatic niche of species evolved has been a topic of high interest in current theoretical and applied macroecological studies. However, little is known regarding how species traits might influence climatic niche evolution. Here, we evaluated patterns of climatic niche evolution in turtles (tortoises and freshwater turtles) and whether species habitat (terrestrial or aquatic) influences these patterns. We used phylogenetic, climatic and distribution data for 261 species to estimate their climatic niches. Then, we compared whether niche overlap between sister species was higher than between random species pairs and evaluated whether niche optima and rates varied between aquatic and terrestrial species. Sister species had higher values of niche overlap than random species pairs, suggesting phylogenetic climatic niche conservatism in turtles. The climatic niche evolution of the group followed an Ornstein–Uhlenbeck model with different optimum values for aquatic and terrestrial species, but we did not find consistent evidence of differences in their rates of climatic niche evolution. We conclude that phylogenetic climatic niche conservatism occurs among turtle species. Furthermore, terrestrial and aquatic species occupy different climatic niches but these seem to have evolved at similar evolutionary rates, reinforcing the importance of habitat in understanding species climatic niches and their evolution.
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Abstract Aim Historical processes that shaped current diversity patterns of seaweeds remain poorly understood. Using Dictyotales, a globally distributed order of brown seaweeds as a model, we test if historical biogeographical and diversification patterns are comparable across clades. Dictyotales contain some 22 genera, three of which,
Dictyota ,Lobophora andPadina , are exceptionally diverse. Specifically, we test whether the evolutionary processes that shaped the latitudinal diversity patterns in these clades are in line with the tropical conservatism, out‐of‐the‐tropics or diversification rate hypotheses.Location Global coastal benthic marine environments.
Taxon Dictyotales (Phaeophyceae).
Methods Species diversity was inferred using DNA‐based species delineation, addressing cryptic diversity and circumventing taxonomic problems. A six‐gene time‐calibrated phylogeny, distribution data of 3,755 specimens and probabilistic modelling of geographical range evolution were used to infer historical biogeographical patterns. The phylogeny was tested against different trait‐dependent models to compare diversification rates for different geographical units as well as different thermal affinities.
Results Our results indicate that Dictyotales originated in the Middle Jurassic and reach a current peak of species diversity in the Central Indo‐Pacific. Ancestral range estimation points to a southern hemisphere origin of Dictyotales corresponding to the tropical southern Tethys Sea. Our results demonstrate that diversification rates were generally higher in tropical regions, but increased diversification rates in different clades are driven by different processes. Our results suggest that three major clades underwent a major diversification burst in the early Cenozoic, with
Dictyota andPadina expanding their distribution into temperate regions whileLobophora retained a predominantly tropical niche.Main conclusions Our results are consistent with both the tropical conservatism hypothesis, in which clades originate and remain in the tropics (
Lobophora ), and the out‐of‐the‐tropics scenario, where taxa originate and expand towards the temperate regions while preserving their presence in the tropics (Dictyota ,Padina ).
