Hierarchical controls on extinction selectivity across the diplobathrid crinoid phylogeny

Paleobiology ◽  
2019 ◽  
pp. 1-20
Author(s):  
Selina R. Cole

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.

Paleobiology ◽  
10.1666/14006 ◽  
2014 ◽  
Vol 40 (4) ◽  
pp. 675-692 ◽  
Author(s):  
Paul G. Harnik ◽  
Paul C. Fitzgerald ◽  
Jonathan L. Payne ◽  
Sandra J. Carlson

Determining which biological traits affect taxonomic durations is critical for explaining macroevolutionary patterns. Two approaches are commonly used to investigate the associations between traits and durations and/or extinction and origination rates: analyses of taxonomic occurrence patterns in the fossil record and comparative phylogenetic analyses, predominantly of extant taxa. By capitalizing upon the empirical record of past extinctions, paleontological data avoid some of the limitations of existing methods for inferring extinction and origination rates from molecular phylogenies. However, most paleontological studies of extinction selectivity have ignored phylogenetic relationships because there is a dearth of phylogenetic hypotheses for diverse non-vertebrate higher taxa in the fossil record. This omission inflates the degrees of freedom in statistical analyses and leaves open the possibility that observed associations are indirect, reflecting shared evolutionary history rather than the direct influence of particular traits on durations. Here we investigate global patterns of extinction selectivity in Devonian terebratulide brachiopods and compare the results of taxonomic vs. phylogenetic approaches. Regression models that assume independence among taxa provide support for a positive association between geographic range size and genus duration but do not indicate an association between body size and genus duration. Brownian motion models of trait evolution identify significant similarities in body size, range size, and duration among closely related terebratulide genera. We use phylogenetic regression to account for shared evolutionary history and find support for a significant positive association between range size and duration among terebratulides that is also phylogenetically structured. The estimated range size–duration relationship is moderately weaker in the phylogenetic analysis due to the down-weighting of closely related genera that were both broadly distributed and long lived; however, this change in slope is not statistically significant. These results provide evidence for the phylogenetic conservatism of organismal and emergent traits, yet also the general phylogenetic independence of the relationship between range size and duration.


Paleobiology ◽  
2008 ◽  
Vol 34 (3) ◽  
pp. 318-341 ◽  
Author(s):  
Seth Finnegan ◽  
Jonathan L. Payne ◽  
Steve C. Wang

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.


2013 ◽  
Vol 41 (1) ◽  
pp. 36 ◽  
Author(s):  
Liangjun HU ◽  
Qinfeng GUO

How species diversity relates to productivity remains a major debate. To date, however, the underlying mechanisms that regulate the ecological processes involved are still poorly understood. Three major issues persist in early efforts at resolution. First, in the context that productivity drives species diversity, how the pathways operate is poorly-explained. Second, productivity  per se varies with community or ecosystem maturity. If diversity indeed drives productivity, the criterion of choosing appropriate measures for productivity is not available. Third, spatial scaling suggests that sampling based on small-plots may not be suitable for formulating species richness-productivity relationships (SRPRs). Thus, the long-standing assumption simply linking diversity with productivity and pursuing a generalizing pattern may not be robust. We argue that productivity, though defined as ‘the rate of biomass production’, has been measured in two ways environmental surrogates and biomass production leading to misinterpretations and difficulty in the pursuit of generalizable SRPRs. To tackle these issues, we developed an integrative theoretical paradigm encompassing richer biological and physical contexts and clearly reconciling the major processes of the systems, using proper productivity measures and sampling units. We conclude that loose interpretation and confounding measures of productivity may be the real root of current SRPR inconsistencies and debate.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stefano Dominici ◽  
Mariagabriella Fornasiero ◽  
Luca Giusberti

AbstractBased on the fossil record, we explore the macroevolutionary relationship between species richness and gigantism in cowries (Cypraeidae), the best-studied family of gastropods, with a global diversity distribution that parallels that of tropical corals, mangroves and seagrasses. We introduce Vicetia bizzottoi sp. nov. based on a Priabonian fossil found in northeastern Italy, the largest documented cowrie found so far and the youngest of a lineage of Eocene Gisortiinae species. The Gisortiinae stratigraphic record in western Europe indicates that species selection favoured large size and armouring of the shell. Palaeoecology and per-stage species richness suggest that gigantism occurred in peripheral habitats with respect to diversity hotspots, where smaller species were favoured. The Eocene–Oligocene boundary was marked by a turnover and the Chattian global warming favoured small-sized species of derived clades. Species selection leading to gigantism is further documented in Miocene lineages of Zoila and Umbilia, in the southern hemisphere, two extant genera distributed at the periphery of modern diversity hotspots, suggesting that the negative relationship between size and diversity is a recurring pattern in the evolutionary history of cowries. This palaeontological evidence is projected onto the existing hypotheses that explain analogous biogeographic patterns in various other taxa. Likewise, body size-species richness negative relationship was possibly driven in cowries by physiological, ecological and life history constraints.


2011 ◽  
Vol 366 (1577) ◽  
pp. 2577-2586 ◽  
Author(s):  
Ben Collen ◽  
Louise McRae ◽  
Stefanie Deinet ◽  
Adriana De Palma ◽  
Tharsila Carranza ◽  
...  

Global species extinction typically represents the endpoint in a long sequence of population declines and local extinctions. In comparative studies of extinction risk of contemporary mammalian species, there appear to be some universal traits that may predispose taxa to an elevated risk of extinction. In local population-level studies, there are limited insights into the process of population decline and extinction. Moreover, there is still little appreciation of how local processes scale up to global patterns. Advancing the understanding of factors which predispose populations to rapid declines will benefit proactive conservation and may allow us to target at-risk populations as well as at-risk species. Here, we take mammalian population trend data from the largest repository of population abundance trends, and combine it with the PanTHERIA database on mammal traits to answer the question: what factors can be used to predict decline in mammalian abundance? We find in general that environmental variables are better determinants of cross-species population-level decline than intrinsic biological traits. For effective conservation, we must not only describe which species are at risk and why, but also prescribe ways to counteract this.


2017 ◽  
Vol 13 (1) ◽  
pp. 20160828 ◽  
Author(s):  
Barry W. Brook ◽  
John Alroy

Extinction is a key feature of the evolutionary history of life, and assessments of extinction risk are essential for the effective protection of biodiversity. The goal in assembling this special issue of Biology Letters was to highlight problems and questions at the research frontier of extinction biology, with an emphasis on recent developments in the methodology of inferring the patterns and processes of extinction from a background of often noisy and sparse data. In selecting topics, we sought to illustrate how extinction is not simply a self-evident phenomenon, but the subject of a dynamic and quantitatively rigorous field of natural science, with practical applications to conservation.


2017 ◽  
Vol 45 (1) ◽  
pp. 1-10 ◽  
Author(s):  
SIMONE FATTORINI ◽  
CRISTINA MANTONI ◽  
LIVIA DE SIMONI ◽  
DIANA M.P. GALASSI

SUMMARYBecause of their isolation, biotic communities of urban green spaces are expected to be similar to those of oceanic islands. This should be particularly true for insects, which represent an important component of urban faunas. The equilibrium theory of island biogeography (ETIB) allows for the formulation of some hypotheses regarding the influence of the geographical characteristics of green spaces on insect species richness and extinction risk. Based on island biogeography principles, we present eight predictions on how green space characteristics should influence insect species richness and loss. We analysed the current literature in order to determine which predictions were supported and which were not. We found that many studies gave outcomes that support ETIB predictions about the effects of area and isolation of green spaces; we found no strong support for predictions about shape and extent of native habitat in the literature that we reviewed. Most of the available studies dealt with patterns in species richness, whereas insect species loss has been rarely investigated. Future developments in the application of island biogeography principles to urban insect conservation should address temporal trends in species persistence and the analysis of species co-occurrence and nestedness.


2015 ◽  
Vol 112 (42) ◽  
pp. 13015-13020 ◽  
Author(s):  
Peter D. Smits

Determining which biological traits influence differences in extinction risk is vital for understanding the differential diversification of life and for making predictions about species’ vulnerability to anthropogenic impacts. Here I present a hierarchical Bayesian survival model of North American Cenozoic mammal species durations in relation to species-level ecological factors, time of origination, and phylogenetic relationships. I find support for the survival of the unspecialized as a time-invariant generalization of trait-based extinction risk. Furthermore, I find that phylogenetic and temporal effects are both substantial factors associated with differences in species durations. Finally, I find that the estimated effects of these factors are partially incongruous with how these factors are correlated with extinction risk of the extant species. These findings parallel previous observations that background extinction is a poor predictor of mass extinction events and suggest that attention should be focused on mass extinctions to gain insight into modern species loss.


2005 ◽  
Vol 55 (4) ◽  
pp. 457-490 ◽  
Author(s):  
Johan Bolhuis

AbstractThe four questions that Niko Tinbergen identified for behavioural biology — evolution, function, development and causation — are all important and should be studied in their own right. Recently, there has been a debate as to whether these four questions should be investigated separately or whether they should be integrated. Integration of the four questions has been attempted in novel research disciplines such as cognitive ecology, evolutionary psychology and neuroecology. Euan Macphail and I have criticised these integrative approaches, suggesting that they are fundamentally flawed as they confound function and mechanism. Investigating the function or evolutionary history of a behaviour or cognitive system is important and entirely legitimate. However, such investigations cannot provide us with answers to questions about the mechanisms underlying behaviour or cognition. At most, functional or evolutionary considerations can provide clues that may be useful for a causal analysis of the underlying mechanisms. However, these clues can be misleading and are often wrong, as is illustrated with examples from song learning and food storing in birds. After summarising the main issues in the neuroecology debate, I discuss some misunderstandings that were apparent in the responses to our critique, as well as some recent relevant data. Recent results do not support the neuroecological approach. Finally, I suggest that the way forward is a cautious and critical use of functional and evolutionary clues in the study of the mechanisms of behaviour.


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