Trends in Ecology & Evolution
Opinion
The Ecology of Nonecological Speciation and Nonadaptive Radiations
Section snippets
On the Origin of Nonadaptive Radiations
Thirteen years after the publication of On the Origin of Species by Means of Natural Selection, Gulick [2] suggested that the most species-rich groups of land snails in Hawaii might have diversified for reasons having little to do with natural selection (see Glossary). Although these species were distinguishable by shell characters, their shells seemed unlikely to be correlated with adaptations to different environments: ‘The conditions under which they live are so completely similar, that it
Properties of Organisms
Since nonadaptive radiations involve both elevated diversification and lack of clade-wide disparity in resource usage, identifying the properties of organisms connected with these factors should help us both uncover and understand nonadaptive radiations. Diversification and lack of disparity may often have different mechanistic underpinnings, so it is useful to consider them separately (Table 2). Understanding which species are prone to geographic isolation and thus allopatric speciation is of
Geography of Nonadaptive Radiation
Geographic distribution is important for understanding species’ evolution and ecology but its interpretation with respect to diversification mode is not always straightforward. Many presently sympatric species are likely to have speciated in allopatry at some point prior. The underlying process at the time of speciation, millions of years ago in some cases, can be difficult to uncover [52], which complicates our understanding of both adaptive and nonadaptive radiations. Many currently sympatric
Community Ecology of Avoiding Competitive Exclusion
In this Opinion article, we treat competition for resources as the primary factor that usually prevents geographic range overlap between ecologically similar taxa. Competitive exclusion is most convincingly demonstrated in small areas (e.g., Petri dishes [64]), but many taxa exist in metapopulations where local extirpation can be balanced by dispersal 67, 68. Patchily distributed, ephemeral resources are permissive of a variety of processes that can allow high degrees of niche overlap at
Concluding Remarks: Macroecology and Conservation Biology of Nonadaptive Radiations
If there is a large-scale geographic gradient of one of the properties of resources and/or habitats that is conducive to nonadaptive radiations, one might expect nonadaptive radiations to be more likely in some places than in others. Chase [91] showed that stochastic assembly is more important in more productive environments (as measured by available phosphorus). This could lead to a positive relationship between species richness and productivity at regional scales that include many smaller
Acknowledgments
We thank Erik Svensson and five anonymous reviewers for their thoughtful and thought-provoking criticisms and comments, which improved this Opinion article. J.E.C-M. thanks Jack Stanford, Mike Kaspari, David Hambright, Adam Kay, Ola Fincke, Brad Stevenson, Bob Nairn, Natalie Clay, Carla Atkinson, David Donoso, Rich Zamor, Jessica Beyer, Thayer Hallidayschult, and Kim Myers for their important discussions on ecology. Both authors thank Warren Allmon for permission to use the framework that
Glossary
- Adaptive radiation
- (i) a pattern of species diversification in which a lineage of species occupies a diversity of ecological roles [90]; and (ii) the evolution of ecological and phenotypic diversity within a rapidly multiplying lineage 7, 15, 19.
- Beta diversity
- can be thought of as the difference between assemblages; in the context of patchy habitats it is sometimes formally defined as the ratio of gamma (regional, or landscape level) diversity to average alpha (local, or patch level) diversity.
References (132)
- et al.
Adaptive radiation, nonadaptive radiation, ecological speciation and nonecological speciation
Trends Ecol. Evol.
(2009) Adaptive radiation, correlated and contingent evolution, and net species diversification in Bromeliaceae
Mol. Phylogenet. Evol.
(2014)Mistaking geography for biology: inferring processes from species distributions
Trends Ecol. Evol.
(2014)The evolving theory of evolutionary radiations
Trends Ecol. Evol.
(2016)Long-distance dispersal: a framework for hypothesis testing
Trends Ecol. Evol.
(2012)- et al.
Evaluating “plasticity-first” evolution in nature: key criteria and empirical approaches
Trends Ecol. Evol.
(2016) - et al.
Phylogenetic comparative methods and the geography of speciation
Trends Ecol. Evol.
(2003) Through thick and thin: cryptic sympatric speciation in the submersed genus Najas (Hydrocharitaceae)
Mol. Phylogenet. Evol.
(2015)Conservation: losing biodiversity by reverse speciation
Curr. Biol.
(2006)Moving character displacement beyond characters using contemporary coexistence theory
Trends Ecol. Evol.
(2018)
Intraspecific aggregation, probability niches and the diversity of soil microarthropod assemblages
Appl. Soil Ecol.
Coexistence and intertidal zonation of chthamalid barnacles along central Chile: interference competition or a lottery for space?
J. Exp. Mar. Biol. Ecol.
Resilience in ecology: abstraction, distraction, or where the action is?
Biol. Conserv.
Coexistence of species
On the variation of species as related to their geographical distribution, illustrated by the Achatinellinæ
Nature
Animal Species and Evolution
Evolution and the Genetics of Populations, Volume 4: Variability Within and Among Natural Populations
Snails on an evolutionary tree: Gulick, speciation, and isolation
Am. Malacol. Bull.
What about non-adaptive radiation?
Biol. J. Linn. Soc. Lond.
The ecology of a continental evolutionary radiation: is the radiation of sigmodontine rodents adaptive?
Evolution
Non-ecological speciation, niche conservatism and thermal adaptation: how are they connected?
Org. Divers. Evol.
The importance (or lack thereof) of niche divergence to the maintenance of a northern species complex: the case of the long-toed salamander (Ambystoma macrodactylum Baird)
J. Evol. Biol.
Macroevolutionary diversification with limited niche disparity in a species-rich lineage of cold-climate lizards
BMC Evol. Biol.
Disintegrating over space and time: paraphyly and species delimitation in the Wehrle’s salamander complex
Zool. Scr.
Glacial refugia, recolonization patterns and diversification forces in Alpine-endemic Megabunus harvestmen
Mol. Ecol.
The challenge of species delimitation at the extremes: diversification without morphological change in Philippine sun skinks
Evolution
Adaptive radiation and molecular systematics: issues and approaches
Community assembly through adaptive radiation in Hawaiian spiders
Science
Co-occurrence of ecologically similar species of Hawaiian spiders reveals critical early phase of adaptive radiation
BMC Evol. Biol.
The Ecology of Adaptive Radiation
Adaptive radiation versus “radiation” and “explosive diversification”: why conceptual distinctions are fundamental to understanding evolution
New Phytol.
The Major Features of Evolution
Approaches to macroevolution: 2. Sorting of variation, some overarching issues, and general conclusions
Evol. Biol.
Testing the hypothesis that a clade has adaptively radiated: iguanid lizard clades as a case study
Am. Nat.
Thinking in continua: beyond the “adaptive radiation” metaphor
Bioessays
Speciation has a spatial scale that depends on levels of gene flow
Am. Nat.
High dispersal ability inhibits speciation in a continental radiation of passerine birds
Proc. Biol. Sci.
Dispersal capacity predicts both population genetic structure and species richness in reef fishes
Am. Nat.
A multi-clade test supports the intermediate dispersal model of biogeography
PLoS One
When Thailand was an island – the phylogeny and biogeography of mite harvestmen (Opiliones, Cyphophthalmi, Stylocellidae) in Southeast Asia: the biogeography of Southeast Asian mite harvestmen
J. Biogeogr.
A new model Gondwanan taxon: systematics and biogeography of the harvestman family Pettalidae (Arachnida, Opiliones, Cyphophthalmi), with a taxonomic revision of genera from Australia and New Zealand
Cladistics
Speciation in Birds
Transplantation of shells
Nature
Prerequisites for flying snails: external transport potential of aquatic snails by waterbirds
Freshw. Sci.
Genetic divergence, reproductive isolation, and marine speciation
Annu. Rev. Ecol. Syst.
The evolutionary ecology of seed size
Marine connectivity dynamics: clarifying cosmopolitan distributions of marine interstitial invertebrates and the meiofauna paradox
Mar. Biol.
Wide distributions and cryptic diversity within a Microstomum (Platyhelminthes) species complex
Zool. Scr.
Phylogenetic niche conservatism: what are the underlying evolutionary and ecological causes?
New Phytol.
Phylogenetic niche conservatism and the evolutionary basis of ecological speciation
Biol. Rev. Camb. Philos. Soc.
Cited by (63)
-
Stochastic processes and changes in evolutionary rate are associated with diversification in a lineage of tropical hard pines (Pinus)
2024, Molecular Phylogenetics and Evolution -
Estimating the non-market value of island biodiversity in China: Controlling for warm glow bias in contingent valuation method
2023, Journal for Nature Conservation -
Cryptic biodiversity in the commercial diamondback squid Thysanoteuthis rhombus Troschel 1857
2024, Reviews in Fish Biology and Fisheries -
Evolution of realized niche breadth diversity driven by community dynamics
2024, Ecology Letters -
The radiation continuum and the evolution of frog diversity
2023, Nature Communications