scholarly journals The Red Queen revisited: reevaluating the age selectivity of Phanerozoic marine genus extinctions

Paleobiology ◽  
2008 ◽  
Vol 34 (3) ◽  
pp. 318-341 ◽  
Author(s):  
Seth Finnegan ◽  
Jonathan L. Payne ◽  
Steve C. Wang
Keyword(s):  
Species Richness ◽  
Extinction Risk ◽  
Geographic Range ◽  
Extinction Rate ◽  
Biological Interactions ◽  
Red Queen ◽  
Apparent Contradiction ◽  
Age Cohorts ◽  
Extinction Selectivity ◽  
Taxonomic Groups

Extinction risk is inversely related to genus age (time since first appearance) in most intervals of the Phanerozoic marine fossil record, in apparent contradiction to the macroevolutionary Red Queen's Hypothesis, which posits that extinction risk is independent of taxon age. Age-dependent increases in the mean species richness and geographic range of genera have been invoked to reconcile this genus-level observation with the presumed prevalence of Red Queen dynamics at the species level. Here we test these explanations with data from the Paleobiology Database. Multiple logistic regression demonstrates that the association of extinction risk with genus age is not adequately explained by species richness or geographic range: there is a residual association between age and extinction risk even when range and richness effects are accounted for. Throughout most of the Phanerozoic the age selectivity gradient is highest among the youngest age cohorts, whereas there is no association between age and extinction risk among older age cohorts. Some of the apparent age selectivity of extinction in the global fauna is attributable to differences in extinction rate among taxonomic groups, but extinction risk declines with genus age even within most taxonomic orders. Notable exceptions to this pattern include the Cambrian-Ordovician, latest Permian, Triassic, and Paleocene intervals. The association of age with extinction risk could reflect sampling heterogeneity or taxonomic practice more than biological reality, but at present it is difficult to evaluate or correct for such biases. Alternatively, the pattern may reflect consistent extinction selectivity on some as-yet unidentified covariate of genus age. Although this latter explanation is not compatible with a Red Queen model if most genus extinctions have resulted from biological interactions, it may be applicable if most genus extinctions have instead been caused by recurrent physical disturbances that repeatedly impose similar selective pressures.

Classifying threatened species: means and ends

1994 ◽  
Vol 344 (1307) ◽  
pp. 91-97 ◽  
Keyword(s):  
Threatened Species ◽  
Extinction Risk ◽  
Conservation Status ◽  
Species Conservation ◽  
Conservation Priorities ◽  
Extinction Rate ◽  
Sources Of Information ◽  
Means And Ends ◽  
Species Area ◽  
Taxonomic Groups

Threatened species lists are widely consulted as sources of information on the conservation status of species. However, their application to planning for conservation is limited because they have not been developed systematically, and because the criteria used to judge extinction risk are subjective. Recently, new proposals have been made to increase the broader usefulness of these lists, and some elements of these proposals are reviewed here. Apart from indicating the geographical and taxonomic groups containing most threatened species, these lists can provide other kinds of information. Some data from threatened species classifications using quantitative criteria provide a new method for estimating extinction rates in a variety of vertebrate taxa. This analysis suggests that over the next 100 years, the extinction rate could be as high as 15-20% in these groups. These values are comparable to those based upon extrapolations from species-area curves. However, allocating threatened species categories is only a first step towards developing rational systems for setting conservation priorities. These systems will need to consider a quite different set of variables, including those for incorporating species conservation priorities in area-based planning

Hierarchical controls on extinction selectivity across the diplobathrid crinoid phylogeny

Paleobiology ◽  
2019 ◽  
pp. 1-20
Author(s):  
Selina R. Cole
Keyword(s):  
Species Richness ◽  
Evolutionary History ◽  
Extinction Risk ◽  
Biological Traits ◽  
Strong Correlations ◽  
Size Selectivity ◽  
Extinction Selectivity ◽  
Food Size ◽  
Underlying Mechanisms ◽  
Primary Predictor

Abstract Identifying correlates of extinction risk is important for understanding the underlying mechanisms driving differential rates of extinction and variability in the temporal durations of taxa. Increasingly, it is recognized that the effects of multiple, potentially interacting variables and phylogenetic relationships should be incorporated when studying extinction selectivity to account for covariation of traits and shared evolutionary history. Here, I explore a variety of biological and ecological controls on genus longevity in the global fossil record of diplobathrid crinoids by analyzing the combined effects of species richness, habitat preference, body size, filtration fan density, and food size selectivity. I employ a suite of taxic and phylogenetic approaches to (1) quantitatively compare and rank the relative effects of multiple factors on taxonomic longevity and (2) determine how phylogenetic comparative approaches alter interpretations of extinction selectivity. I find controls on diplobathrid genus duration are hierarchically structured, where species richness is the primary predictor of duration, habitat is the secondary predictor, and combinations of ecological and biological traits are tertiary controls. Ecology plays an important but complex role in the generation of crinoid macroevolutionary patterns. Notably, tolerance of environmental heterogeneity promotes increased genus duration across diplobathrid crinoids, and the effects of traits related to feeding ecology vary depending on habitat lithology. Finally, I find accounting for phylogeny does not consistently decrease the significance of correlations between traits and genus duration, as is commonly expected. Instead, the strength of relationships between traits and duration may increase, decrease, or remain statistically similar, and both the magnitude and direction of these shifts are generally unpredictable. However, traits with strong correlations and/or moderately large effect sizes (Cohen's f2 > 0.15) under taxic approaches tend to remain qualitatively unchanged under phylogenetic approaches.

The impact of geographic range, sampling, ecology, and time on extinction risk in the volatile clade Graptoloida

Paleobiology ◽  
2016 ◽  
Vol 43 (1) ◽  
pp. 85-113 ◽  
Author(s):  
James Boyle ◽  
H. David Sheets ◽  
Shuang-Ye Wu ◽  
Daniel Goldman ◽  
Michael J. Melchin ◽  
...  
Keyword(s):  
Ecological Niche ◽  
Extinction Risk ◽  
Biological Effects ◽  
Abiotic Factors ◽  
Explanatory Power ◽  
Negative Relationship ◽  
Geographic Range ◽  
Range Size ◽  
Age Cohorts ◽  
The Impact

AbstractAlthough extinction risk has been found to have a consistent negative relationship with geographic range across wide temporal and taxonomic scales, the effect has been difficult to disentangle from factors such as sampling, ecological niche, or clade. In addition, studies of extinction risk have focused on benthic invertebrates with less work on planktic taxa. We employed a global set of 1114 planktic graptolite species from the Ordovician to lower Devonian to analyze the predictive power of species’ traits and abiotic factors on extinction risk, combining general linear models (GLMs), partial least-squares regression (PLSR), and permutation tests. Factors included measures of geographic range, sampling, and graptolite-specific factors such as clade, biofacies affiliation, shallow water tolerance, and age cohorts split at the base of the Katian and Rhuddanian stages.The percent variance in durations explained varied substantially between taxon subsets from 12% to 45%. Overall commonness, the correlated effects of geographic range and sampling, was the strongest, most consistent factor (12–30% variance explained), with clade and age cohort adding up to 18% and other factors <10%. Surprisingly, geographic range alone contributed little explanatory power (<5%). It is likely that this is a consequence of a nonlinear relationship between geographic range and extinction risk, wherein the largest reductions in extinction risk are gained from moderate expansion of small geographic ranges. Thus, even large differences in range size between graptolite species did not lead to a proportionate difference in extinction risk because of the large average ranges of these species. Finally, we emphasize that the common practice of determining the geographic range of taxa from the union of all occurrences over their duration poses a substantial risk of overestimating the geographic scope of the realized ecological niche and, thus, of further conflating sampling effects on observed duration with the biological effects of range size on extinction risk.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

scholarly journals The effects of geographic range size and abundance on extinction during a time of “sluggish”’ evolution

Paleobiology ◽  
2020 ◽  
pp. 1-14
Author(s):  
Michelle M. Casey ◽  
Erin E. Saupe ◽  
Bruce S. Lieberman
Keyword(s):  
North American ◽  
Fossil Record ◽  
Extinction Risk ◽  
Geographic Range ◽  
Range Size ◽  
Late Paleozoic ◽  
The North ◽  
Geographic Range Size ◽  
The Relationship ◽  
Habitat Tracking

Abstract Geographic range size and abundance are important determinants of extinction risk in fossil and extant taxa. However, the relationship between these variables and extinction risk has not been tested extensively during evolutionarily “quiescent” times of low extinction and speciation in the fossil record. Here we examine the influence of geographic range size and abundance on extinction risk during the late Paleozoic (Mississippian–Permian), a time of “sluggish” evolution when global rates of origination and extinction were roughly half those of other Paleozoic intervals. Analyses used spatiotemporal occurrences for 164 brachiopod species from the North American midcontinent. We found abundance to be a better predictor of extinction risk than measures of geographic range size. Moreover, species exhibited reductions in abundance before their extinction but did not display contractions in geographic range size. The weak relationship between geographic range size and extinction in this time and place may reflect the relative preponderance of larger-ranged taxa combined with the physiographic conditions of the region that allowed for easy habitat tracking that dampened both extinction and speciation. These conditions led to a prolonged period (19–25 Myr) during which standard macroevolutionary rules did not apply.

scholarly journals The pitfalls of biodiversity proxies: Differences in richness patterns of birds, trees and understudied diversity across Amazonia

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Camila D. Ritter ◽  
Søren Faurby ◽  
Dominic J. Bennett ◽  
Luciano N. Naka ◽  
Hans ter Steege ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Spatial Scales ◽  
Local Environment ◽  
Life Forms ◽  
Taxonomic Group ◽  
Diversity Gradients ◽  
Richness Patterns ◽  
Taxonomic Groups ◽  
Micro Organisms

AbstractMost knowledge on biodiversity derives from the study of charismatic macro-organisms, such as birds and trees. However, the diversity of micro-organisms constitutes the majority of all life forms on Earth. Here, we ask if the patterns of richness inferred for macro-organisms are similar for micro-organisms. For this, we barcoded samples of soil, litter and insects from four localities on a west-to-east transect across Amazonia. We quantified richness as Operational Taxonomic Units (OTUs) in those samples using three molecular markers. We then compared OTU richness with species richness of two relatively well-studied organism groups in Amazonia: trees and birds. We find that OTU richness shows a declining west-to-east diversity gradient that is in agreement with the species richness patterns documented here and previously for birds and trees. These results suggest that most taxonomic groups respond to the same overall diversity gradients at large spatial scales. However, our results show a different pattern of richness in relation to habitat types, suggesting that the idiosyncrasies of each taxonomic group and peculiarities of the local environment frequently override large-scale diversity gradients. Our findings caution against using the diversity distribution of one taxonomic group as an indication of patterns of richness across all groups.

scholarly journals Distribution of birds in Colombia

2021 ◽  
Vol 9 ◽  
Author(s):  
Danny Vélez ◽  
Edwin Tamayo ◽  
Fernando Ayerbe-Quiñones ◽  
Julián Torres ◽  
Juan Rey ◽  
...  
Keyword(s):  
Decision Making ◽  
Species Richness ◽  
Land Use Planning ◽  
Scientific Information ◽  
Sustainable Use ◽  
Bird Species ◽  
Geographic Information ◽  
Huge Number ◽  
Bird Species Richness ◽  
Taxonomic Groups

1. Colombia with 1941 known recorded bird species is one of the most species rich countries in the world. Efforts are necessary to conserve, study and promote sustainable use of this important taxonomic group throughout Colombia’s vast territory. 2. In an ideal world, informed decisions that are based on sound scientific information should be likelier to have successful outcomes. Nevertheless, there are barriers that make it difficult to access and use information in a timely fashion. Those same barriers impede the study, conservation and sustainable use of bird species in Colombia. On the other hand, given that there is good documentation about the ecology of a large number of species, information about the distribution of birds can be easily incorporated into decision-making processes, once this information becomes readily available in a consumable format using Geographic Information Sciences tools. 3. In this context, the main objective of this paper is to present the first compilation of the current distribution of 1889 (97%) species of birds in Colombia, using expert criteria. The shapefiles were used to show the distribution and diversity of bird species in Colombia under both geopolitical and conservation geographic units. 4. The information provided in this paper can be used as a baseline for a huge number of initiatives that aim to strengthen conservation efforts and improve knowledge about one the most unique taxonomic groups in the country. These range from land use planning strategies at the municipal or department scale to sustainable use of bird species - such as those initiatives related to bird watching - in Colombia. This study has considered three key aspects: 1) the importance of birds for Colombia’s ecosystems, 2) the privileged place of Colombia in bird species richness and 3) the importance of data mobilisation in formats easily consumable by Geographic Information Systems (GIS) to facilitate the processes of informed decision-making. We present the first compilation - in shapefile format - for 1889 of the 1941 bird species recorded from Colombia. Using this novel collection, we showed the species richness of birds in Colombia’s 33 Departments plus its Captial District (DPs), 1122 Municipalities (MNs), 58 protected areas (PAs), 39 Regional Autonomous Corporations (the authorities responsible within their respective jurisdictions for regulating the environment and renewable natural resources in Colombia; CARs) and 916 Collectively Titled Territories (including both indigenous reservations and afro-descendant communities; CTTs). In addition, we provide a list of known bird species richness for the above geographic units found in the available literature. The information provided here can be used as a baseline for a huge number of initiatives concerning the study, conservation and sustainable use of bird species present in Colombia, providing access to key features of bird distribution that should facilitate decision-making.

scholarly journals Quantifying geographic range measures and their utility as extinction risk proxies

2017 ◽  
Author(s):  
James Boyle
Keyword(s):  
Convex Hull ◽  
Sample Size ◽  
Cell Count ◽  
Spanning Tree ◽  
Minimum Spanning Tree ◽  
Extinction Risk ◽  
Geographic Range ◽  
Western Hemisphere ◽  
True Value ◽  
Latitudinal Range

Geographic range is used as a correlate of extinction risk for extant and extinct organisms across the fields of conservation and paleobiology. However, the exact method used to measure geographic range, the biases, and the limitations of each are rarely discussed explicitly despite their potential to impact conclusions. Here I examine and quantify properties of five commonly used measures of geographic range (convex hull area, maximum pairwise great circle distance, latitudinal range, longitudinal range, and cell count) along with a rarely used measure (minimum spanning tree distance) in the context of three datasets. A simulated dataset of two shapes with known areal limits, a paleontological occurrence dataset of pre-Cenozoic brachiopod genera from the Paleobiology Database (PBDB), and 50000 occurrence records of birds species in the western hemisphere from the eBird database. Simulated distributions indicate that when a distribution is simple (i.e. a rectangle) all measures are similarly accurate and precise at varying sample sizes and all measures converge toward the true value with increasing sample size. However, given a more complex distribution (i.e. horseshoe shape) the convex hull area becomes increasingly inaccurate as sample size increases even as it becomes more precise. Within the PBDB dataset the minimum spanning tree was heavily favored by Akaike Information Criterion as the most effective predictor of extinction risk. Analysis of the eBird data set indicated differences between IUCN Red List Categories were significant for all geographic range measures. Overall, these results suggest that for the purpose of categorical comparisons, such as those between victims and survivors of an extinction event, all six geographic range measures are interchangeable. However, the magnitude of the relationship between geographic range and extinction risk is strongly dependent on the choice of measure. Simple linear measures, such as latitudinal range, were relatively poor predictors while minimum spanning tree and cell count measures were strong predictors, especially after sampling was accounted for. The minimum spanning tree measure was found to perform at the same level or better than most other measures with the main drawback being that it is computationally expensive.

scholarly journals Effects of Malaise trap spacing on species richness and composition of terrestrial arthropod bulk samples

2020 ◽  
Author(s):  
D Steinke ◽  
TWA Braukmann ◽  
L Manerus ◽  
A Woodhouse ◽  
V Elbrecht
Keyword(s):  
Species Richness ◽  
Field Experiments ◽  
Collection Efficiency ◽  
Malaise Trap ◽  
Number Of Factors ◽  
Large Numbers ◽  
Set Up ◽  
Taxonomic Groups ◽  
A Site ◽  
Malaise Traps

AbstractThe Malaise trap has gained popularity for assessing diverse terrestrial arthropod communities because it collects large samples with modest effort. A number of factors that influence collection efficiency, placement being one of them. For instance, when designing larger biotic surveys using arrays of Malaise traps we need to know the optimal distance between individual traps that maximises observable species richness and community composition. We examined the influence of spacing between Malaise traps by metabarcoding samples from two field experiments at a site in Waterloo, Ontario, Canada. For one experiment, we used two trap pairs deployed at weekly increasing distance (3m increments from 3 to 27 m). The second experiment involved a total of 10 traps set up in a row at 3m distance intervals for three consecutive weeks.Results show that community similarity of samples decreases over distance between traps. The amount of species shared between trap pairs shows drops considerably at about 15m trap-to-trap distance. This change can be observed across all major taxonomic groups and for two different habitat types (grassland and forest). Large numbers of OTUs found only once within samples cause rather large dissimilarity between distance pairs even at close proximity. This could be caused by a large number of transient species from adjacent habitat which arrive at the trap through passive transport, as well as capture of rare taxa, which end up in different traps by chance.

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