Three prominent explanations have been proposed to explain the dramatic differences in species richness across regions and elevations, (i) time for speciation, (ii) diversification rates, and (iii) ecological limits. But the relative importance of these explanations and, especially, their interplay and possible synthesis remain largely elusive. Integrating diversification analyses, null models, and geographic information systems, I study avian richness across regions and elevations of the New World. My results reveal that even though the three explanations are differentially important (with ecological limits playing the dominant role), each contributes uniquely to the formation of richness gradients. Further, my results reveal the likely interplay between the explanations. They indicate that ecological limits hinder the diversification process, such that the accumulation of species within a region gradually slows down over time. Yet, it does not seem to converge toward a hard ceiling on regional richness. Instead, species-rich regions show suppressed, but continued, diversification, coupled with signatures of possible competition (esp. Neotropical lowlands). Conversely, species-poor, newly-colonized regions show fast diversification and weak to no signs of competition (esp. Nearctic highlands). These results held across five families of birds, across grid cells, biomes, and elevations. Together, my findings begin to illuminate the rich, yet highly consistent, interplay of the mechanisms that together shape richness gradients in the New World, including the most species-rich biodiversity hotspots on the planet, the Andes and the Amazon. [Biogeography; community; competition; macroevolution; phylogenetics; richness gradient.].

Biodiversity Research Centre University of British Columbia 2212 Main Mall Vancouver V6T 1Z4 Canada

Center for Macroecology Evolution and Climate University of Copenhagen Universitetsparken 15 DK 2100 Copenhagen Denmark

Center for Theoretical Study Charles University Jilska 1 110 00 Praha 1 Czech Republic

Department of Ecology Charles University Vinicna 7 12844 Praha 2 Czech Republic

Zobrazit více v PubMed

Belmaker J., Jetz W.  2015. Relative roles of ecological and energetic constraints, diversification rates and region history on global species richness gradients. Ecol. Lett.  18:563–571. PubMed

Benton M.J., Emerson B.C.  2007. How did life become so diverse?  The dynamics of diversification according to the fossil record and molecular phylogenetics. Palaeontology  50:23–40.

Bleiweiss R.  1998. Origin of hummingbird faunas. Biol. J. Linn. Soc.  65:77–97.

Blomberg S.P., Garland T., Ives A.R.  2003. Testing for phylogenetic signal in comparative data: behavioral traits are more labile. Evolution  57:717–745. PubMed

Brown J.H.  2014. Why are there so many species in the tropics?  J. Biogeogr.  41:8–22. PubMed PMC

Cavender-Bares J., Kozak K.H., Fine P.V.A., Kembel S.W.  2009. The merging of community ecology and phylogenetic biology. Ecol. Lett.  12:693–715. PubMed

Chesson P.  2000. Mechanisms of maintenance of species diversity. Annu. Rev. Ecol. Syst.  31:343–366.

Cornell H.V.  2013. Is regional species diversity bounded or unbounded?  Biol. Rev.  88:140–165. PubMed

Cracraft J., Claramunt S.  2017. Conceptual and analytical worldviews shape differences about global avian biogeography. J. Biogeogr.  44:958–960.

Darwin C.  1859. The origin of species. Reprint Edition New York: Signet Press.

Derryberry E.P., Claramunt S., Derryberry G., Chesser R.T., Cracraft J., Aleixo A., Pérez-Emán J., Remsen J. V. J., Brumfield R.T.  2011. Lineage diversification and morphological evolution in a large-scale continental radiation: the Neotropical ovenbirds and woodcreepers (Aves: Furnariidae). Evolution  65:2973–2986. PubMed

Diaz L.F.H., Harmon L.J., Sugawara M.T.C., Miller E.T., Pennell M.W.  2019. Macroevolutionary diversification rates show time dependency. Proc. Natl. Acad. Sci. USA  116:7403–7408. PubMed PMC

Diniz-Filho J.A.F., Bini L.M., Hawkins B.A.  2003. Spatial autocorrelation and red herrings in geographical ecology. Glob. Ecol. Biogeogr.  12:53–64.

Dobzhansky T.  1950. Evolution in the tropics. Am. Sci.  38:209–221.

Donoghue M.J.  2008. A phylogenetic perspective on the distribution of plant diversity. Proc. Natl. Acad. Sci. USA  105:11549–11555. PubMed PMC

Economo E.P., Narula N., Friedman N.R., Weiser M.D., Guénard B.  2018. Macroecology and macroevolution of the latitudinal diversity gradient in ants. Nat. Commun.  9:1778. PubMed PMC

Ericson P.G.P.  2011. Evolution of terrestrial birds in three continents: biogeography and parallel radiations. J. Biogeogr.  39:813–824.

Ericson P.G.P., Irestedt M., Johansson U.S.  2003. Evolution, biogeography, and patterns of diversification in passerine birds. J. Avian Biol.  34:3–15.

Erwin D.H.  2008. Macroevolution of ecosystem engineering, niche construction and diversity. Trends Ecol. Evol.  23:304–310. PubMed

Evans K.L., Warren P.H., Gaston K.J.  2005. Species-energy relationships at the macroecological scale: a review of the mechanisms. Biol. Rev.  80:1–25. PubMed

Fine P.V.A.  2015. Ecological and evolutionary drivers of geographic variation in species diversity. Annu. Rev. Ecol. Evol. Syst.  46:369–392.

Fischer A.G.  1960. Latitudinal variations in organic diversity. Evolution  14:64–81.

Fjeldsa J., Bowie R.C.K., Rahbek C.  2012. The role of mountain ranges in the diversification of birds. Annu. Rev. Ecol. Evol. Syst.  43:249–265.

Gaston K.J.  2000. Global patterns in biodiversity. Nature  405:220–227. PubMed

Goldberg E.E., Lancaster L.T., Ree R.H.  2011. Phylogenetic inference of reciprocal effects between geographic range evolution and diversification. Syst. Biol.  60:451–465. PubMed

Gotelli N.J.  2000. Null model analysis of species co-occurrence patterns. Ecology  81:2606–2621.

Gotelli N.J., Graves G.R.  1996. Null models in ecology. Washington: Smithsonian.

Graham C.H., Carnaval A.C., Cadena C.D., Zamudio K.R., Roberts T.E., Parra J.L., McCain C.M., Bowie R.C.K., Moritz C., Baines S.B., Schneider C.J., VanDerWal J., Rahbek C., Kozak K.H., Sanders N.J.  2014. The origin and maintenance of montane diversity: integrating evolutionary and ecological processes. Ecography  37:711–719.

Graham C.H., Parra J.L., Rahbek C., McGuire J.A.  2009. Phylogenetic structure in tropical hummingbird communities. Proc. Natl. Acad. Sci. USA  106:19673–19678. PubMed PMC

Graham C.H., Storch D., Machac A.  2018. Phylogenetic scale in ecology and evolution. Glob. Ecol. Biogeogr.  27:175–187.

Harmon L.J., Harrison S.  2015. Species diversity is dynamic and unbounded at local and continental scales. Am. Nat.  185:584–593. PubMed

Hawkins B.A., Field R., Cornell H.V., Currie D.J., Guegan J.F., Kaufman D.M., Kerr J.T., Mittelbach G.G., Oberdorff T., O’Brien E.M., Porter E.E., Turner J.R.G.  2003. Energy, water, and broad-scale geographic patterns of species richness. Ecology  84:3105–3117.

Hawkins B.A., McCain C.M., Davies T.J., Buckley L.B., Anacker B.L., Cornell H.V., Damschen E.I., Grytnes J.-A., Harrison S., Holt R.D., Kraft N.J.B., Stephens P.R.  2012. Different evolutionary histories underlie congruent species richness gradients of birds and mammals. J. Biogeogr.  39:825–841.

Hedges S.B., Marin J., Suleski M., Paymer M., Kumar S.  2015. Tree of life reveals clock-like speciation and diversification. Mol. Biol. Evol.  4:835–845. PubMed PMC

Hohna S., Landis M.J., Heath T.A., Boussau B., Lartillot N., Moore B.R., Huelsenbeck J.P., Ronquist F.  2016. RevBayes: Bayesian phylogenetic inference using graphical models and an interactive model-specification language. Syst. Biol.  65:726–736. PubMed PMC

Hoorn C., Wesselingh F.P., ter Steege H., Bermudez M.A., Mora A., Sevink J., Sanmartín I., Sanchez-Meseguer A., Anderson C.L., Figueiredo J.P., Jaramillo C., Riff D., Negri F.R., Hooghiemstra H., Lundberg J., Stadler T., Särkinen T., Antonelli A.  2010. Amazonia through time: Andean uplift, climate change, landscape evolution, and biodiversity. Science  330:927–931. PubMed

von Humboldt A., Bonpland A.  1807. Essay on the geography of plants. Reprint Edition Chicago: University of Chicago Press.

Hurlbert A.H., Jetz W.  2007. Species richness, hotspots, and the scale dependence of range maps in ecology and conservation. Proc. Natl. Acad. Sci. USA  104:13384–13389. PubMed PMC

Hutchinson G.E.  1957. Concluding remarks. Cold Spring Harb. Symp. Quant. Biol.  22:415–427.

Hutter C.R., Guayasamin J.M., Wiens J.J.  2013. Explaining Andean megadiversity: the evolutionary and ecological causes of glassfrog elevational richness patterns. Ecol. Lett.  16:1135–1144. PubMed

Isaac N.J.B., Turvey S.T., Collen B., Waterman C., Baillie J.E.M.  2007. Mammals on the EDGE: conservation priorities based on threat and phylogeny. PLoS One  2:e296. PubMed PMC

Jablonski D., Roy K., Valentine J.W.  2006. Out of the tropics: evolutionary dynamics of the latitudinal diversity gradient. Science  314:102–106. PubMed

Janzen D.H.  1967. Why mountain passes are higher in the tropics. Am. Nat.  919:233–249.

Jarvis E.D., Mirarab S., Aberer A.J., Li B., Houde P., Li C., Ho S.Y.W., Faircloth B.C., Nabholz B., Howard J.T., Suh A., Weber C.C., da Fonseca R.R., Li J., Zhang F., Li H., Zhou L., Narula N., Liu L., Ganapathy G., Boussau B., Bayzid M.S., Zavidovych V., Subramanian S., Gabaldón T., Capella-Gutiérrez S., Huerta-Cepas J., Rekepalli B., Munch K., Schierup M., Lindow B., Warren W.C., Ray D., Green R.E., Bruford M.W., Zhan X., Dixon A., Li S., Li N., Huang Y., Derryberry E.P., Bertelsen M.F., Sheldon F.H., Brumfield R.T., Mello C.V., Lovell P.V., Wirthlin M., Schneider M.P.C., Prosdocimi F., Samaniego J.A., Velazquez A.M.V., Alfaro-Núñez A., Campos P.F., Petersen B., Sicheritz-Ponten T., Pas A., Bailey T., Scofield P., Bunce M., Lambert D.M., Zhou Q., Perelman P., Driskell A.C., Shapiro B., Xiong Z., Zeng Y., Liu S., Li Z., Liu B., Wu K., Xiao J., Yinqi X., Zheng Q., Zhang Y., Yang H., Wang J., Smeds L., Rheindt F.E., Braun M., Fjeldsa J., Orlando L., Barker F.K., Jønsson K.A., Johnson W., Koepfli K.-P., O’Brien S., Haussler D., Ryder O.A., Rahbek C., Willerslev E., Graves G.R., Glenn T.C., McCormack J., Burt D., Ellegren H., Alström P., Edwards S.V., Stamatakis A., Mindell D.P., Cracraft J., Braun E.L., Warnow T., Jun W., Gilbert M.T.P., Zhang G.  2014. Whole-genome analyses resolve early branches in the tree of life of modern birds. Science  346:1320–1331. PubMed PMC

Jetz W., Fine P.V.A.  2012. Global gradients in vertebrate diversity predicted by historical area-productivity dynamics and contemporary environment. PLoS Biol.  10:e1001292. PubMed PMC

Jetz W., Rahbek C.  2002. Geographic range size and determinants of avian species richness. Science  297:1548–1551. PubMed

Jetz W., Thomas G.H., Joy J.B., Hartmann K., Mooers A.O.  2012. The global diversity of birds in space and time. Nature  491:444–448. PubMed

Karger D.N., Conrad O., Böhner J., Kawohl T., Kreft H., Soria-Auza R.W., Zimmermann N.E., Linder H.P., Kessler M.  2017. Climatologies at high resolution for the earth’s land surface areas. Sci. Data.  4:170122. PubMed PMC

Kembel S.W., Cowan P.D., Helmus M.R., Cornwell W.K., Morlon H., Ackerly D.D., Blomberg S.P., Webb C.O.  2010. Picante: R tools for integrating phylogenies and ecology. Bioinformatics  26:1463–1464. PubMed

Kennedy J.D., Borregaard M.K., Marki P.Z., Machac A., Fjeldsa J., Rahbek C.  2018. Expansion in geographical and morphological space drives continued lineage diversification in a global passerine radiation. Proc. R. Soc. B Biol. Sci.  285:20182181. PubMed PMC

Kozak K.H., Wiens J.J.  2012. Phylogeny, ecology, and the origins of climate-richness relationships. Ecology  93:167–181.

Losos J.B.  2010. Adaptive radiation, ecological opportunity, and evolutionary determinism. Am. Nat.  175:623–39. PubMed

Machac A., Graham C.H.  2017. Regional diversity and diversification in mammals. Am. Nat.  189:1–13. PubMed

Machac A., Graham C.H., Storch D.  2018. Ecological controls of mammalian diversification vary with phylogenetic scale. Glob. Ecol. Biogeogr.  27:32–46.

Machac A., Janda M., Dunn R.R., Sanders N.J.  2011. Elevational gradients in phylogenetic structure of ant communities reveal the interplay of biotic and abiotic constraints on diversity. Ecography  34:364–371.

Mannion P.D., Upchurch P., Benson R.B.J., Goswami A.  2014. The latitudinal biodiversity gradient through deep time. Trends Ecol. Evol.  29:42–50. PubMed

Marin J., Hedges S.B.  2016. Time best explains global variation in species richness of amphibians, birds and mammals. J. Biogeogr.  43:1069–1079.

Marin J., Rapacciuolo G., Costa G.C., Graham C.H., Brooks T.M., Young B.E., Radeloff V.C., Behm J.E., Helmus M.R., Hedges S.B.  2018. Evolutionary time drives global tetrapod diversity. Proc. R. Soc. B Biol. Sci.  285:20172378. PubMed PMC

Matzke N.J.  2014. Model selection in historical biogeography reveals that founder-event speciation is a crucial process in island clades. Syst. Biol.  63:951–970. PubMed

Mayfield M.M., Levine J.M.  2010. Opposing effects of competitive exclusion on the phylogenetic structure of communities: phylogeny and coexistence. Ecol. Lett.  13:1085–1093. PubMed

McGuire J.A., Witt C.C., Remsen Jr. J.V., Corl A., Rabosky D.L., Altshuler D.L., Dudley R.  2014. Molecular phylogenetics and the diversification of hummingbirds. Curr. Biol.  24:910–916. PubMed

McPeek M.A.  2008. The ecological dynamics of clade diversification and community assembly. Am. Nat.  172:270–284. PubMed

Mittelbach G.G., Schemske D.W., Cornell H.V., Allen A.P., Brown J.M., Bush M.B., Harrison S.P., Hurlbert A.H., Knowlton N., Lessios H.A., McCain C.M., McCune A.R., McDade L.A., McPeek M.A., Near T.J., Price T.D., Ricklefs R.E., Roy K., Sax D.F., Schluter D., Sobel J.M., Turelli M.  2007. Evolution and the latitudinal diversity gradient: speciation, extinction and biogeography. Ecol. Lett.  10:315–331. PubMed

Moore B.R., Höhna S., May M.R., Rannala B., Huelsenbeck J.P.  2016. Critically evaluating the theory and performance of Bayesian analysis of macroevolutionary mixtures. Proc. Natl. Acad. Sci. USA  113:9569–9574. PubMed PMC

Morlon H.  2014. Phylogenetic approaches for studying diversification. Ecol. Lett.  17:508–525. PubMed

Morlon H., Potts M.D., Plotkin J.B.  2010. Inferring the dynamics of diversification: a coalescent approach. PLoS Biol.  8:e1000493. PubMed PMC

Mu Q., Zhao M., Running S.W.  2011. Improvements to a MODIS global terrestrial evapotranspiration algorithm. Remote Sens. Environ.  115:1781–1800.

Myers N., Mittermeier R.A., Mittermeier C.G., da Fonseca G.A.B., Kent J.  2000. Biodiversity hotspots for conservation priorities. Nature  403:853. PubMed

Nelder J.A., Wedderburn R.W.M.  1972. Generalized linear models. J. R. Stat. Soc.  135:370–384.

Oliveira B.F., Machac A., Costa G.C., Brooks T.M., Davidson A.D., Rondinini C., Graham C.H.  2016. Species and functional diversity accumulate differently in mammals. Glob. Ecol. Biogeogr.  25:1119–1130.

Olson D.M., Dinerstein E., Wikramanayake E.D., Burgess N.D., Powell G.V.N., Underwood E.C., D’amico J.A., Itoua I., Strand H.E., Morrison J.C., Loucks C.J., Allnutt T.F., Ricketts T.H., Kura Y., Lamoreux J.F., Wettengel W.W., Hedao P., Kassem K.R.  2001. Terrestrial ecoregions of the world: a new map of life on Earth. BioScience  51:933–938.

Pagel M.  1999. Inferring the historical patterns of biological evolution. Nature.  401:877–884. PubMed

Paradis E., Claude J., Strimmer K.  2004. APE: analyses of phylogenetics and evolution in R language. Bioinformatics  20:289–290. PubMed

Pianka E.  1966. Latitudinal gradients in species diversity: a review of concepts. Am. Nat.  100:33–46.

Pontarp M., Wiens J.J.  2017. The origin of species richness patterns along environmental gradients: uniting explanations based on time, diversification rate and carrying capacity. J. Biogeogr.  44:722–735.

Prum R.O., Berv J.S., Dornburg A., Field D.J., Townsend J.P., Lemmon E.M., Lemmon A.R.  2015. A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing. Nature  526:569–573. PubMed

Quintero I., Jetz W.  2018. Global elevational diversity and diversification of birds. Nature  555:246. PubMed

Rabosky D.L.  2013. Diversity-dependence, ecological speciation, and the role of competition in macroevolution. Annu. Rev. Ecol. Evol. Syst.  44:481–502.

Rabosky D.L.  2014. Automatic detection of key innovations, rate shifts, and diversity-dependence on phylogenetic trees. PLoS One  9:e89543. PubMed PMC

Rabosky D.L., Chang J., Title P.O., Cowman P.F., Sallan L., Friedman M., Kaschner K., Garilao C., Near T.J., Coll M., Alfaro M.E.  2018. An inverse latitudinal gradient in speciation rate for marine fishes. Nature  559:392–395. PubMed

Rabosky D.L., Glor R.E.  2010. Equilibrium speciation dynamics in a model adaptive radiation of island lizards. Proc. Natl. Acad. Sci. USA  107:22178–22183. PubMed PMC

Rabosky D.L., Goldberg E.E.  2015. Model inadequacy and mistaken inferences of trait-dependent speciation. Syst. Biol.  64:340–355. PubMed

Rabosky D.L., Mitchell J.S., Chang J.  2017. Is BAMM flawed?  Theoretical and practical concerns in the analysis of multi-rate diversification models. Syst. Biol.  66:477–498. PubMed PMC

Rabosky D.L., Title P.O., Huang H.  2015. Minimal effects of latitude on present-day speciation rates in New World birds. Proc. R. Soc. B Biol. Sci.  282:20142889. PubMed PMC

Rahbek C.  1995. The elevational gradient of species richness: a uniform pattern?  Ecography  18:200–205.

Rahbek C.  2005. The role of spatial scale and the perception of large-scale species-richness patterns. Ecol. Lett.  8:224–239.

Rahbek C., Graves G.R.  2001. Multiscale assessment of patterns of avian species richness. Proc. Natl. Acad. Sci. USA  98:4534–4539. PubMed PMC

Revell L.J.  2011. phytools: an R package for phylogenetic comparative biology. Methods Ecol. Evol.  3:217–223.

Ricklefs R.E.  2006. Global variation in the diversification rate of passerine birds. Ecology  87:2468–2478. PubMed

Ricklefs R.E., Schluter D.  1994. Species diversity in ecological communities. Chicago: University of Chicago Press.

Rohde K.  1992. Latitudinal gradients in species-diversity: the search for the primary cause. Oikos  65:514–527.

Rolland J., Condamine F.L., Jiguet F., Morlon H.  2014. Faster speciation and reduced extinction in the tropics contribute to the mammalian latitudinal diversity gradient. PLoS Biol.  12:e1001775. PubMed PMC

Ronquist F., Sanmartin I.  2011. Phylogenetic methods in biogeography. Annu. Rev. Ecol. Evol. Syst.  42:441–464.

Rosenzweig. 1995. Species diversity in space and time. Cambridge: Cambridge University Press.

Schemske D.W., Mittelbach G.G., Cornell H.V., Sobel J.M., Roy K.  2009. Is there a latitudinal gradient in the importance of biotic interactions?  Annu. Rev. Ecol. Evol. Syst.  40:245–269.

Schluter D.  2000. The ecology of adaptive radiation. New York: Oxford University Press.

Schluter D.  2009. Evidence for ecological speciation and its alternative. Science  323:737–741. PubMed

Schluter D.  2016. Speciation, ecological opportunity, and latitude. Am. Nat.  187:1–18. PubMed

Sepkoski J.J.  1981. A factor analytic description of the Phanerozoic marine fossil record. Paleobiology  7:36–53.

Šímová I., Storch D.  2016. The enigma of terrestrial primary productivity: measurements, models, scales and the diversity–productivity relationship. Ecography  40:239–252.

Simpson G.G.  1953. The major features of evolution. New York: Columbia University Press.

Stanley S.M.  1979. Macroevolution: pattern and process. Baltimore: Johns Hopkins University Press.

Stebbins G.L.  1974. Flowering plants: evolution above the species level. Boston: Belknap Press.

Stephens P.R., Wiens J.J.  2003. Explaining species richness from continents to communities: the time-for-speciation effect in emydid turtles. Am. Nat.  161:112–128. PubMed

Stevens G.C.  1992. The elevational gradient in altitudinal range: an extension of Rapoport’s latitudinal rule to altitude. Am. Nat.  140:893–911. PubMed

Storch D., Bohdalková E., Okie J.  2018. The more-individuals hypothesis revisited: the role of community abundance in species richness regulation and the productivity–diversity relationship. Ecol. Lett.  21:920–937. PubMed

Storch D., Okie J.G.  2019. The carrying capacity for species richness. Glob. Ecol. Biogeogr.  28:1519–1532.

Stroud J.T., Losos J.B.  2016. Ecological opportunity and adaptive radiation. Annu. Rev. Ecol. Evol. Syst.  47:507–532.

Van Valen L.  1985. A theory of origination and extinction. Evol. Theory  12:133–142.

Souto-Vilarós D., Machac A., Michalek J., Darwell C.T., Sisol M., Kuyaiva T., Isua B., Weiblen G.D., Novotny V., Segar S.T.  2019. Faster speciation of fig-wasps than their host figs leads to decoupled speciation dynamics: snapshots across the speciation continuum. Mol. Ecol.  28:3958–3976. PubMed

Walker T., Valentine J.  1984. Equilibrium-models of evolutionary species-diversity and the number of empty niches. Am. Nat.  124:887–899.

Wallace A.R.  1889. Darwinism: an exposition of the theory of natural selection with some of its applications. London: Macmillan & Co.

Webb C.O.  2000. Exploring the phylogenetic structure of ecological communities: an example for rain forest trees. Am. Nat.  156:145–155. PubMed

Webb C.O., Ackerly D.D., McPeek M.A., Donoghue M.J.  2002. Phylogenies and community ecology. Annu. Rev. Ecol. Syst.  33:475–505.

Weir J.T., Schluter D.  2007. The latitudinal gradient in recent speciation and extinction rates of birds and mammals. Science  315:1574–1576. PubMed

Whittaker R.H.  1972. Evolution and measurement of species diversity. Taxon  21:213.

Wiens J.J.  2007. Global patterns of diversification and species richness in amphibians. Am. Nat.  170:86–106. PubMed

Wiens J.J.  2011. The causes of species richness patterns across space, time, and clades and the role of ecological limits. Q. Rev. Biol.  86:75–96. PubMed

Wiens J.J., Ackerly D.D., Allen A.P., Anacker B.L., Buckley L.B., Cornell H.V., Damschen E.I., Jonathan Davies T., Grytnes J.-A., Harrison S.P., Hawkins B.A., Holt R.D., McCain C.M., Stephens P.R.  2010. Niche conservatism as an emerging principle in ecology and conservation biology. Ecol. Lett.  13:1310–1324. PubMed

Wiens J.J., Donoghue M.J.  2004. Historical biogeography, ecology and species richness. Trends Ecol. Evol.  19:639–644. PubMed

Willis J.C.  1922. Age and area: a study in geographical distribution and origin of species. Cambridge: Cambridge University Press.

Yoder J.B., Clancey E., Des Roches S., Eastman J.M., Gentry L., Godsoe W., Hagey T.J., Jochimsen D., Oswald B.P., Robertson J., Sarver B. a. J., Schenk J.J., Spear S.F., Harmon L.J.  2010. Ecological opportunity and the origin of adaptive radiations. J. Evol. Biol.  23:1581–1596. PubMed

Zhao M.S., Heinsch F.A., Nemani R.R., Running S.W.  2005. Improvements of the MODIS terrestrial gross and net primary production global data set. Remote Sens. Environ.  95:164–176.

The relationship between geographic range size and rates of species diversification

Morphology and niche evolution influence hummingbird speciation rates