Conserved ancestral tropical niche but different continental histories explain the latitudinal diversity gradient in brush-footed butterflies

AbstractThe global increase in species richness toward the tropics across continents and taxonomic groups, referred to as the latitudinal diversity gradient, stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluate several of these hypotheses to explain spatial diversity patterns in a butterfly family, the Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal, and also the extent to which these processes differ among regions at the same latitude. We generate a time-calibrated phylogeny containing 2,866 nymphalid species (~45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the latitudinal diversity gradient among regions because temporal diversification dynamics differ greatly across longitude. The Neotropical diversity results from low extinction rates, not high speciation rates, and biotic interchanges with other regions are rare. Southeast Asia is also characterized by a low speciation rate but, unlike the Neotropics, is the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, combined with tropical niche conservatism, played a major role in generating the modern latitudinal diversity gradient of nymphalid butterflies.

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The latitudinal diversity gradient in brush-footed butterflies (Nymphalidae): conserved ancestral tropical niche but different continental histories

10.1101/2020.04.16.045575 ◽

2020 ◽

Cited By ~ 1

Author(s):

Nicolas Chazot ◽

Fabien L. Condamine ◽

Gytis Dudas ◽

Carlos Peña ◽

Pavel Matos-Maraví ◽

...

Keyword(s):

Global Climate ◽

Spatial Diversity ◽

Extinction Rate ◽

Latitudinal Diversity Gradient ◽

Extinction Rates ◽

Diversity Gradient ◽

Speciation Rates ◽

Global Increase ◽

Underlying Mechanisms ◽

Taxonomic Groups

AbstractThe latitudinal diversity gradient (LDG) is arguably one of the most striking patterns in nature. The global increase in species richness toward the tropics across continents and taxonomic groups stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluated several of these hypotheses to explain spatial diversity patterns in the butterfly family, Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal to the LDG, and also the extent to which these processes differ among regions at the same latitude. We generated a new, time-calibrated phylogeny of Nymphalidae based on 10 gene fragments and containing ca. 2,800 species (∼45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the LDG among regions because temporal diversification dynamics differ greatly across longitude. For example, we found that Neotropical nymphalid diversity results from low extinction rates, not high speciation rates, and that biotic interchanges with other regions were rare. Southeast Asia was also characterized by a low speciation rate but, unlike the Neotropics, was the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, particularly during the Eocene-Oligocene transition, combined with the conserved ancestral tropical niches, played a major role in generating the modern LDG of butterflies.

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Taxonomic evolution in North American Neogene horses (subfamily Equinae): the rise and fall of an adaptive radiation

Paleobiology ◽

10.1017/s0094837300015888 ◽

1993 ◽

Vol 19 (2) ◽

pp. 216-234 ◽

Cited By ~ 65

Author(s):

Richard C. Hulbert

Keyword(s):

Species Richness ◽

Steady State ◽

Adaptive Radiation ◽

Middle Miocene ◽

Extinction Rate ◽

Extinction Rates ◽

Speciation Rates ◽

History Of ◽

Very High ◽

Radiation Phase

The 18 m.y. history of the subfamily Equinae (exclusive of Archaeohippus and “Parahippus”) in North America consisted of a 3-m.y. radiation phase, a 9-m.y. steady-state diversity phase, and a 6-m.y. reduction phase. During the steady-state phase, species richness varied between 14 and 20, with two maxima at about 13.5 and 6.5 Ma. Species richness of the tribes Hipparionini and Equini was about equal through the middle Miocene, but hipparionines consistently had more species in the late Miocene and early Pliocene. Overall mean species duration was 3.2 m.y. (n = 50), or an average extinction rate of 0.31 m.y.-1 During the radiation phase, speciation rates were very high (0.5 to 1.4 m.y.-1), while extinction rates were low (<0.10 m.y.-1). Speciation and extinction rates both averaged about 0.15 m.y.-1 during the steady-state phase, with extinction rates having more variation. Extinction rates increased fourfold during the reduction phase, while speciation rates declined slightly. Late Hemphillian extinctions affected both tribes severely, not just the three-toed hipparionines, and were correlated with global climatic change.

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A latitudinal diversity gradient of shallow-water gorgonians (Cnidaria: Octocorallia: Alcyonacea) along the Tropical Eastern Pacific Ocean: testing for underlying mechanisms

Marine Biodiversity ◽

10.1007/s12526-019-01006-1 ◽

2019 ◽

Vol 49 (6) ◽

pp. 2787-2800

Author(s):

Mónica Núñez–Flores ◽

Andrés Solórzano ◽

Cristián E. Hernández ◽

Pablo J. López–González

Keyword(s):

Pacific Ocean ◽

Shallow Water ◽

Eastern Pacific ◽

Eastern Pacific Ocean ◽

Tropical Eastern Pacific ◽

Latitudinal Diversity Gradient ◽

Diversity Gradient ◽

Underlying Mechanisms

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The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.1125 ◽

2020 ◽

Vol 287 (1929) ◽

pp. 20201125 ◽

Cited By ~ 2

Author(s):

Bethany J. Allen ◽

Paul B. Wignall ◽

Daniel J. Hill ◽

Erin E. Saupe ◽

Alexander M. Dunhill

Keyword(s):

Mass Extinction ◽

Large Scale ◽

Middle Triassic ◽

Global Climate ◽

Time Interval ◽

Late Permian ◽

Biodiversity Patterns ◽

Latitudinal Diversity Gradient ◽

Earth History ◽

Diversity Gradient

The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian–Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian–Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20–40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.

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Late Cenozoic onset of the latitudinal diversity gradient of North American mammals

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1524750113 ◽

2016 ◽

Vol 113 (26) ◽

pp. 7189-7194 ◽

Cited By ~ 21

Author(s):

Jonathan D. Marcot ◽

David L. Fox ◽

Spencer R. Niebuhr

Keyword(s):

North America ◽

North American ◽

Global Climate ◽

Temporal And Spatial Variation ◽

Latitudinal Diversity Gradient ◽

Terrestrial Mammals ◽

Diversity Gradient ◽

Temporal And Spatial ◽

Living Organisms

The decline of species richness from equator to pole, or latitudinal diversity gradient (LDG), is nearly universal among clades of living organisms, yet whether it was such a pervasive pattern in the geologic past remains uncertain. Here, we calculate the strength of the LDG for terrestrial mammals in North America over the past 65 My, using 27,903 fossil occurrences of Cenozoic terrestrial mammals from western North America downloaded from the Paleobiology Database. Accounting for temporal and spatial variation in sampling, the LDG was substantially weaker than it is today for most of the Cenozoic and the robust modern LDG of North American mammals evolved only over the last 4 My. The strength of the LDG correlates negatively with global temperature, suggesting a role of global climate patterns in the establishment and maintenance of the LDG for North American mammals.

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Adjusting global extinction rates to account for taxonomic susceptibility

Paleobiology ◽

10.1666/07060.1 ◽

2008 ◽

Vol 34 (4) ◽

pp. 434-455 ◽

Cited By ~ 18

Author(s):

Steve C. Wang ◽

Andrew M. Bush

Keyword(s):

Inverse Correlation ◽

Volcanic Eruptions ◽

Time Interval ◽

Extinction Rate ◽

Mass Extinctions ◽

Sea Level Changes ◽

Marine Fauna ◽

Extinction Rates ◽

Global Extinction ◽

Taxonomic Groups

Studies of extinction in the fossil record commonly involve comparisons of taxonomic extinction rates, often expressed as the percentage of taxa (e.g., families or genera) going extinct in a time interval. Such extinction rates may be influenced by factors that do not reflect the intrinsic severity of an extinction trigger. Two identical triggering events (e.g., bolide impacts, sea level changes, volcanic eruptions) could lead to different taxonomic extinction rates depending on factors specific to the time interval in which they occur, such as the susceptibility of the fauna or flora to extinction, the stability of food webs, the positions of the continents, and so on. Thus, it is possible for an extinction event with a higher taxonomic extinction rate to be caused by an intrinsically less severe trigger, compared to an event with a lower taxonomic extinction rate.Here, we isolate the effects of taxonomic susceptibility on extinction rates. Specifically, we quantify the extent to which the taxonomic extinction rate in a substage is elevated or depressed by the vulnerability to extinction of classes extant in that substage. Using a logistic regression model, we estimate that the taxonomic susceptibility of marine fauna to extinction has generally declined through the Phanerozoic, and we adjust the observed extinction rate in each substage to estimate the intrinsic extinction severity more accurately. We find that mass extinctions do not generally occur during intervals of unusually high susceptibility, although susceptibility sometimes increases in post-extinction recovery intervals. Furthermore, the susceptibility of specific animal classes to extinction is generally similar in times of background and mass extinction, providing no evidence for differing regimes of extinction selectivity. Finally, we find an inverse correlation between extinction rate within substages and the evenness of diversity of major taxonomic groups, but further analyses indicate that low evenness itself does not cause high rates of extinction.

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Graptoloid evolutionary rates track Ordovician–Silurian global climate change

Geological Magazine ◽

10.1017/s0016756813000198 ◽

2013 ◽

Vol 151 (2) ◽

pp. 349-364 ◽

Cited By ~ 56

Author(s):

ROGER A. COOPER ◽

PETER M. SADLER ◽

AXEL MUNNECKE ◽

JAMES S. CRAMPTON

Keyword(s):

Species Richness ◽

Evolutionary Dynamics ◽

Global Climate ◽

Mean Value ◽

Evolutionary Rates ◽

Extinction Rate ◽

Extinction Rates ◽

History Of ◽

Mass Depletion ◽

Climatic Regime

AbstractGraptoloid evolutionary dynamics show a marked contrast from the Ordovician to the Silurian. Subdued extinction and origination rates during the Ordovician give way, during the late Katian, to rates that were highly volatile and of higher mean value through the Silurian, reflecting the significantly shorter lifespan of Silurian species. These patterns are revealed in high-resolution rate curves derived from the CONOP (constrained optimization) scaled and calibrated global composite sequence of 2094 graptoloid species. The end-Ordovician mass depletion was driven primarily by an elevated extinction rate which lasted forc. 1.2 Ma with two main spikes during the Hirnantian. The early Silurian recovery, although initiated by a peak in origination rate, was maintained by a complex interplay of origination and extinction rates, with both rates rising and falling sharply. The global δ13C curve echoes the graptoloid evolutionary rates pattern; the prominent and well-known positive isotope excursions during the Late Ordovician and Silurian lie on or close to times of sharp decline in graptoloid species richness, commonly associated with extinction rate spikes. The graptoloid and isotope data point to a relatively steady marine environment in the Ordovician with mainly background extinction rates, changing during the Katian to a more volatile climatic regime that prevailed through the Silurian, with several sharp extinction episodes triggered by environmental crises. The correlation of graptoloid species diversity with isotopic ratios was positive in the Ordovician and negative in the Silurian, suggesting different causal linkages. Throughout the history of the graptoloid clade all major depletions in species richness except for one were caused by elevated extinction rate rather than decreased origination rate.

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Yes, a non‐random distribution, but why do dragonflies and damselflies not follow latitudinal gradient rules?

10.22541/au.163705573.37659202/v1 ◽

2021 ◽

Author(s):

Maya Rocha ◽

Freddy Palacino ◽

Pilar Rodríguez ◽

Alex Córdoba-Aguilar

Keyword(s):

Species Richness ◽

Community Assembly ◽

Latitudinal Gradient ◽

Environmental Filtering ◽

Phylogenetic Structure ◽

Latitudinal Diversity Gradient ◽

Diversity Gradient ◽

Historical Processes ◽

Underlying Mechanisms ◽

Different Origins

1. Latitudinal diversity gradient (LDG) is the increase in species richness towards the equator and is one of the most consistent patterns in biogeography, where current and historical processes contribute to shape the pattern. 2. Despite that LDG patterns have been described for some insects, the underlying mechanisms associated with community assembly and diversification along modern latitudinal diversity gradient pattern remain unknowledge for many groups. 3. Odonata is an old order of insects that originated during the Carboniferous and has diversified through different eras. Here, we defined co-occurrence based on the presence in ecoregions and 1°×1° grid cells of Odonata species in North America NA, to address their species richness, phylogenetic structure, and species diversification rate along the latitudinal gradient. 4. For the whole order, we found the highest species richness at mid-latitudes, while phylogenetic diversity showed a linear positive pattern along the gradient. Our results showed dragonfly assemblages were clustered along all the gradient, suggesting that environmental filtering sorted the assemblages. Whereas damselfly species assemblages were clustered at mid-latitude and overdispersed into both extremes of gradient, probably community assembly is driving by thermal gradients at mid-latitude, by competitive exclusion at south extreme, and by different origins of the biota at the boreal zone. Our results show that apparently most ancestral lineages of Odonata inhabit tropical zones, where diversified and dispersed to the temperate region, although likely also have been diversified into regions of NA, which might be linked with the highest species richness at mid-latitude for both suborders.

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