scholarly journals Graptoloid evolutionary rates track Ordovician–Silurian global climate change

2013 ◽  
Vol 151 (2) ◽  
pp. 349-364 ◽  
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.

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

Paleobiology ◽  
1993 ◽  
Vol 19 (2) ◽  
pp. 216-234 ◽  
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.

scholarly journals Phylogenetic diversity as a window into the evolutionary and biogeographic histories of present-day richness gradients for mammals

2011 ◽  
Vol 366 (1576) ◽  
pp. 2414-2425 ◽  
Author(s):  
T. Jonathan Davies ◽  
Lauren B. Buckley
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Diversity Indices ◽  
Environmental Predictors ◽  
Terrestrial Mammals ◽  
Extinction Rates ◽  
Biogeographic History ◽  
Shared Ancestry ◽  
History Of ◽  
Dispersal Events

Phylogenetic diversity (PD) captures the shared ancestry of species, and is increasingly being recognized as a valuable conservation currency. Regionally, PD frequently covaries closely with species richness; however, variation in speciation and extinction rates and/or the biogeographic history of lineages can result in significant deviation. Locally, these differences may be pronounced. Rapid recent speciation or high temporal turnover of lineages can result in low PD but high richness. In contrast, rare dispersal events, for example, between biomes, can elevate PD but have only small impact on richness. To date, environmental predictors of species richness have been well studied but global models explaining variation in PD are lacking. Here, we contrast the global distribution of PD versus species richness for terrestrial mammals. We show that an environmental model of lineage diversification can predict well the discrepancy in the distribution of these two variables in some places, for example, South America and Africa but not others, such as Southeast Asia. When we have information on multiple diversity indices, conservation efforts directed towards maximizing one currency or another (e.g. species richness versus PD) should also consider the underlying processes that have shaped their distributions.

scholarly journals The evolutionary dynamics of the early Palaeozoic marine biodiversity accumulation

2019 ◽  
Vol 286 (1909) ◽  
pp. 20191634 ◽  
Author(s):  
Björn Kröger ◽  
Franziska Franeck ◽  
Christian M. Ø. Rasmussen
Keyword(s):  
Life Expectancy ◽  
Temporal Resolution ◽  
Evolutionary Dynamics ◽  
Marine Ecosystems ◽  
Evolutionary Rates ◽  
Marine Biodiversity ◽  
Ecosystem Resilience ◽  
Extinction Rates ◽  
Late Cambrian ◽  
Early Palaeozoic

The early Palaeozoic Era records the initial biodiversification of the Phanerozoic. The increase in biodiversity involved drastic changes in taxon longevity, and in rates of origination and extinction. Here, we calculate these variables in unprecedented temporal resolution. We find that highly volatile origination and extinction rates are associated with short genus longevities during the Cambrian Period. During the Ordovician and Silurian periods, evolutionary rates were less volatile and genera persisted for increasingly longer intervals. The 90%-genus life expectancy doubled from 5 Myr in the late Cambrian to more than 10 Myr in the Ordovician–Silurian periods. Intervals with widespread ecosystem disruption are associated with short genus longevities during the Cambrian and with exceptionally high longevities during the Ordovician and Silurian periods. The post-Cambrian increase in persistence of genera, therefore, indicates an elevated ability of the changing early Palaeozoic marine ecosystems to sustainably maintain existing genera. This is evidence of a new level of ecosystem resilience which evolved during the Ordovician Period.

A kinetic model of Phanerozoic taxonomic diversity II. Early Phanerozoic families and multiple equilibria

Paleobiology ◽  
1979 ◽  
Vol 5 (3) ◽  
pp. 222-251 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Kinetic Model ◽  
Multiple Equilibria ◽  
Dynamic Equilibrium ◽  
Taxonomic Diversity ◽  
Extinction Rate ◽  
Two Phase ◽  
Extinction Rates ◽  
History Of ◽  
Extinction Events ◽  
Middle And Late Cambrian

The kinetic model of taxonomic diversity predicts that the long-term diversification of taxa within any large and essentially closed ecological system should approximate a logistic process controlled by changes in origination and extinction rates with changing numbers of taxa. This model is tested with a new compilation of numbers of metazoan families known from Paleozoic stages (including stage-level subdivisions of the Cambrian). These data indicate the occurrence of two intervals of logistic diversification within the Paleozoic. The first interval, spanning the Vendian and Cambrian, includes an approximately exponential increase in families across the Precambrian-Cambrian Boundary and a “pseudo-equilibrium” through the Middle and Late Cambrian, caused by diversity-dependent decrease in origination rate and increase in extinction rate. The second interval begins with a rapid re-diversification in the Ordovician, which leads to a tripling of familial diversity during a span of 50 Myr; by the end of the Ordovician diversity attains a new dynamic equilibrium that is maintained, except for several extinction events, for nearly 200 Myr until near the end of the Paleozoic. A “two-phase” kinetic model is constructed to describe this heterogeneous pattern of early Phanerozoic diversification. The model adequately describes the “multiple equilibria,” the asymmetrical history of the “Cambrian fauna,” the extremely slow initial diversification of the later “Paleozoic fauna,” and the combined patterns of origination and extinction in both faunas. It is suggested that this entire pattern of diversification reflects the early success of ecologically generalized taxa and their later replacement by more specialized taxa.

scholarly journals Settling down of seasonal migrants promotes bird diversification

2014 ◽  
Vol 281 (1784) ◽  
pp. 20140473 ◽  
Author(s):  
Jonathan Rolland ◽  
Frédéric Jiguet ◽  
Knud Andreas Jønsson ◽  
Fabien L. Condamine ◽  
Hélène Morlon
Keyword(s):  
Species Richness ◽  
Sedentary Behaviour ◽  
Evolutionary History ◽  
Seasonal Migration ◽  
Migratory Behaviour ◽  
Migratory Species ◽  
Diversification Rates ◽  
Extinction Rates ◽  
History Of ◽  
Daughter Species

How seasonal migration originated and impacted diversification in birds remains largely unknown. Although migratory behaviour is likely to affect bird diversification, previous studies have not detected any effect. Here, we infer ancestral migratory behaviour and the effect of seasonal migration on speciation and extinction dynamics using a complete bird tree of life. Our analyses infer that sedentary behaviour is ancestral, and that migratory behaviour evolved independently multiple times during the evolutionary history of birds. Speciation of a sedentary species into two sedentary daughter species is more frequent than speciation of a migratory species into two migratory daughter species. However, migratory species often diversify by generating a sedentary daughter species in addition to the ancestral migratory one. This leads to an overall higher migratory speciation rate. Migratory species also experience lower extinction rates. Hence, although migratory species represent a minority (18.5%) of all extant birds, they have a higher net diversification rate than sedentary species. These results suggest that the evolution of seasonal migration in birds has facilitated diversification through the divergence of migratory subpopulations that become sedentary, and illustrate asymmetrical diversification as a mechanism by which diversification rates are decoupled from species richness.

Diversity and evolutionary rates of Cambro-Ordovician nautiloids

Paleobiology ◽  
1981 ◽  
Vol 7 (2) ◽  
pp. 216-229 ◽  
Author(s):  
Rex E. Crick
Keyword(s):  
North American ◽  
Fossil Record ◽  
Evolutionary Rates ◽  
Time Interval ◽  
Time Intervals ◽  
Frequency Distributions ◽  
Extinction Rates ◽  
History Of ◽  
Biological Aspects ◽  
Stratigraphic Ranges

The history of diversity, origination and extinction of Cambro-Ordovician nautiloid cephalopods is explored to determine if differences in evolutionary rates between nautiloid orders are sufficient to document significantly high or low rates of evolutionary turnover (taxotely of Raup and Marshall 1980). The stratigraphic ranges of 425 nautiloid genera are analyzed for this purpose.Evolutionary rates for five of the seven time intervals analyzed fall within frequency distributions of rates which are thought to be characteristic for a given time interval (horotelic distribution of Simpson 1944). Sufficient heterogeneity is present among extinction rates of Arenigian orders and origination rates of Caradocian orders to reject the null hypotheses of horotely in favor of taxotely. The orders Ellesmerocerida and Tarphycerida, each with a significantly high rate of extinction (P ≥ 0.99), and the Actinocerida, with a significantly low rate of extinction (P ≥ 0.99), were responsible for taxotely during the Arenigian. The Oncocerida and Discosorida, each with a significantly high rate of origination (P ≥ 0.99), were responsible for taxotely during the Caradocian. In each case, taxotely is attributable to the influence of North American endemics. This effect is believed to be more the result of real biological aspects of nautiloid evolution than an artifact of the fossil record.

scholarly journals Decline in extinction rates and scale invariance in the fossil record

Paleobiology ◽  
1999 ◽  
Vol 25 (4) ◽  
pp. 434-439 ◽  
Author(s):  
M. E. J. Newman ◽  
Gunther J. Eble
Keyword(s):  
Power Spectrum ◽  
Power Law ◽  
Fossil Record ◽  
Scale Invariance ◽  
Evolutionary Dynamics ◽  
Extinction Rate ◽  
Extinction Rates ◽  
Self Organized ◽  
Critical Theories ◽  
Extinction Events

We show that the decline in the extinction rate during the Phanerozoic can be accurately described by a logarithmic fit to the cumulative total extinction. This implies that extinction intensity is falling off approximately as the reciprocal of time. We demonstrate that this observation alone is sufficient to explain the existence of the proposed power-law forms in the distribution of the sizes of extinction events and in the power spectrum of Phanerozoic extinction, results that previously have been explained by appealing to self-organized critical theories of evolutionary dynamics.

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

2020 ◽  
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.

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

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nicolas Chazot ◽  
Fabien L. Condamine ◽  
Gytis Dudas ◽  
Carlos Peña ◽  
Ullasa Kodandaramaiah ◽  
...  
Keyword(s):  
Global Climate ◽  
Spatial Diversity ◽  
Extinction Rate ◽  
Latitudinal Diversity Gradient ◽  
Extinction Rates ◽  
Diversity Gradient ◽  
Speciation Rates ◽  
Global Increase ◽  
Underlying Mechanisms ◽  
Taxonomic Groups

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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