Drilling predation increased in response to changing environments in the Caribbean Neogene

Paleobiology ◽  
2016 ◽  
Vol 42 (3) ◽  
pp. 394-409 ◽  
Author(s):  
Jill S. Leonard-Pingel ◽  
Jeremy B. C. Jackson

AbstractChanges in the physical environment are major drivers of evolutionary change, either through direct effects on the distribution and abundance of species or more subtle shifts in the outcome of biological interactions. To investigate this phenomenon, we built a fossil data set of drilling gastropod predation on bivalve prey for the last 11 Myr to determine how the regional collapse in Caribbean upwelling and planktonic productivity affected predator–prey interactions. Contrary to theoretical expectations, predation increased nearly twofold after productivity declined, while the ratio of drilling predators to prey remained unchanged. This increase reflects a gradual, several-fold increase in the extent of shallow-water coral reefs and seagrass meadows in response to the drop in productivity that extended over several million years. Drilling predation is uniformly higher in biogenic habitats than in soft sediments. Thus, changes in predation intensity were driven by a shift in dominant habitats rather than a direct effect of decreased productivity. Most previous analyses of predation through time have not accounted for variations in environmental conditions, raising questions about the patterns observed. More fundamentally, however, the consequences of large-scale environmental perturbations may not be instantaneous, especially when changes in habitat and other aspects of local environmental conditions cause cascading series of effects.

Paleobiology ◽  
2015 ◽  
Vol 41 (2) ◽  
pp. 353-367 ◽  
Author(s):  
Jonathan S. Mitchell

AbstractEvolutionary inferences from fossil data often require accurately reconstructing differences in richness and morphological disparity between fossil sites across space and time. Biases such as sampling and rock availability are commonly accounted for in large-scale studies; however, preservation bias is usually dealt with only in smaller, more focused studies. Birds represent a diverse, but taphonomically fragile, group commonly used to infer environmental conditions in recent (Pleistocene and later) fossil assemblages, and their relative scarcity in the fossil record has led to controversy over the timing of their radiation. Here, I use simulations to show how even weak taphonomic biases can distort estimates of richness, and render variance sensitive to sample size. I then apply an ecology-based filtering model to recent bird assemblages to quantify the distortion induced by taphonomy. Certain deposit types, such as caves, show less evidence of taphonomic distortion than others, such as fluvial and lacustrine deposits. Archaeological middens unsurprisingly show some of the strongest evidence for taphonomic bias, and they should be avoided when reconstructing Pleistocene and early Holocene environments. Further, these results support previously suggested methods for detecting fossil assemblages that are relatively faithfully preserved (e.g., presence of difficult-to-preserve taxa), and I use these results to recommend that future large-scale studies include facies diversity along with metrics such as rock volume, or compare only sites with similar taphonomic histories.


Author(s):  
Katherine A. Williams ◽  
Helen D. Slater ◽  
Phillipa Gillingham ◽  
Amanda H. Korstjens

AbstractUnderstanding the neutral, biological, and environmental processes driving species distributions is valuable in informing conservation efforts because it will help us predict how species will respond to changes in environmental conditions. Environmental processes affect species differently according to their biological traits, which determine how they interact with their environment. Therefore, functional, trait-based modeling approaches are considered important for predicting distributions and species responses to change but even for data-rich primate communities our understanding of the relationships between traits and environmental conditions is limited. Here we use a large-scale, high-resolution data set of African diurnal primate distributions, biological traits, and environmental conditions to investigate the role of biological traits and environmental trait filtering in primate distributions. We collected data from published sources for 354 sites and 14 genera with 57 species across sub-Saharan Africa. We then combined a three-table ordination method, RLQ, with the fourth-corner approach to test relationships between environmental variables and biological traits and used a mapping approach to visually assess patterning in primate genus and species’ distributions. We found no significant relationships between any groups of environmental variables and biological traits, despite a clear role of environmental filtering in driving genus and species’ distributions. The most important environmental driver of species distributions was temperature seasonality, followed by rainfall. We conclude that the relative flexibility of many primate genera means that not any one particular set of traits drives their species–environment associations, despite the clear role of such associations in their distribution patterns.


Geology ◽  
2021 ◽  
Author(s):  
A.D. Muscente ◽  
Rowan C. Martindale ◽  
Anirudh Prabhu ◽  
Xiaogang Ma ◽  
Peter Fox ◽  
...  

Ecological observations and paleontological data show that communities of organisms recur in space and time. Various observations suggest that communities largely disappear in extinction events and appear during radiations. This hypothesis, however, has not been tested on a large scale due to a lack of methods for analyzing fossil data, identifying communities, and quantifying their turnover. We demonstrate an approach for quantifying turnover of communities over the Phanerozoic Eon. Using network analysis of fossil occurrence data, we provide the first estimates of appearance and disappearance rates for marine animal paleocommunities in the 100 stages of the Phanerozoic record. Our analysis of 124,605 fossil collections (representing 25,749 living and extinct marine animal genera) shows that paleocommunity disappearance and appearance rates are generally highest in mass extinctions and recovery intervals, respectively, with rates three times greater than background levels. Although taxonomic change is, in general, a fair predictor of ecologic reorganization, the variance is high, and ecologic and taxonomic changes were episodically decoupled at times in the past. Extinction rate, therefore, is an imperfect proxy for ecologic change. The paleocommunity turnover rates suggest that efforts to assess the ecological consequences of the present-day biodiversity crisis should focus on the selectivity of extinctions and changes in the prevalence of biological interactions.


1984 ◽  
Vol 41 (12) ◽  
pp. 1722-1729 ◽  
Author(s):  
J. Anthony Koslow

By analysing recruitment time series for 14 stocks of northwest Atlantic fish, I have found consistent positive correlations in recruitment among stocks within such species as cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and herring (Clupea harengus). Significant positive correlations are also often found in recruitment among demersal, offshore-spawning species (cod, haddock, and redfish (Sebastes spp.)), and recruitment in these groups tends to be negatively correlated with that of pelagic species, which spawn inshore (herring) or in restricted waters (mackerel (Scomber scombrus)). These patterns emerge as well from a principal component (PC) analysis of the recruitment data. Three dominant patterns (PC 1–3) explain 78% of the variance of the data set. I suggest that the spatial extent of these patterns, which span the region from west Greenland to Georges Bank, indicates that large-scale physical forcing, rather than local biological interactions, predominantly regulates recruitment to northwest Atlantic fisheries.


2020 ◽  
Vol 5 (4) ◽  
pp. 959-970
Author(s):  
Kelly M. Reavis ◽  
James A. Henry ◽  
Lynn M. Marshall ◽  
Kathleen F. Carlson

Purpose The aim of this study was to examine the relationship between tinnitus and self-reported mental health distress, namely, depression symptoms and perceived anxiety, in adults who participated in the National Health and Nutrition Examinations Survey between 2009 and 2012. A secondary aim was to determine if a history of serving in the military modified the associations between tinnitus and mental health distress. Method This was a cross-sectional study design of a national data set that included 5,550 U.S. community-dwelling adults ages 20 years and older, 12.7% of whom were military Veterans. Bivariable and multivariable logistic regression was used to estimate the association between tinnitus and mental health distress. All measures were based on self-report. Tinnitus and perceived anxiety were each assessed using a single question. Depression symptoms were assessed using the Patient Health Questionnaire, a validated questionnaire. Multivariable regression models were adjusted for key demographic and health factors, including self-reported hearing ability. Results Prevalence of tinnitus was 15%. Compared to adults without tinnitus, adults with tinnitus had a 1.8-fold increase in depression symptoms and a 1.5-fold increase in perceived anxiety after adjusting for potential confounders. Military Veteran status did not modify these observed associations. Conclusions Findings revealed an association between tinnitus and both depression symptoms and perceived anxiety, independent of potential confounders, among both Veterans and non-Veterans. These results suggest, on a population level, that individuals with tinnitus have a greater burden of perceived mental health distress and may benefit from interdisciplinary health care, self-help, and community-based interventions. Supplemental Material https://doi.org/10.23641/asha.12568475


2009 ◽  
Vol 28 (11) ◽  
pp. 2737-2740
Author(s):  
Xiao ZHANG ◽  
Shan WANG ◽  
Na LIAN

Author(s):  
Eun-Young Mun ◽  
Anne E. Ray

Integrative data analysis (IDA) is a promising new approach in psychological research and has been well received in the field of alcohol research. This chapter provides a larger unifying research synthesis framework for IDA. Major advantages of IDA of individual participant-level data include better and more flexible ways to examine subgroups, model complex relationships, deal with methodological and clinical heterogeneity, and examine infrequently occurring behaviors. However, between-study heterogeneity in measures, designs, and samples and systematic study-level missing data are significant barriers to IDA and, more broadly, to large-scale research synthesis. Based on the authors’ experience working on the Project INTEGRATE data set, which combined individual participant-level data from 24 independent college brief alcohol intervention studies, it is also recognized that IDA investigations require a wide range of expertise and considerable resources and that some minimum standards for reporting IDA studies may be needed to improve transparency and quality of evidence.


2020 ◽  
Vol 47 (3) ◽  
pp. 547-560 ◽  
Author(s):  
Darush Yazdanfar ◽  
Peter Öhman

PurposeThe purpose of this study is to empirically investigate determinants of financial distress among small and medium-sized enterprises (SMEs) during the global financial crisis and post-crisis periods.Design/methodology/approachSeveral statistical methods, including multiple binary logistic regression, were used to analyse a longitudinal cross-sectional panel data set of 3,865 Swedish SMEs operating in five industries over the 2008–2015 period.FindingsThe results suggest that financial distress is influenced by macroeconomic conditions (i.e. the global financial crisis) and, in particular, by various firm-specific characteristics (i.e. performance, financial leverage and financial distress in previous year). However, firm size and industry affiliation have no significant relationship with financial distress.Research limitationsDue to data availability, this study is limited to a sample of Swedish SMEs in five industries covering eight years. Further research could examine the generalizability of these findings by investigating other firms operating in other industries and other countries.Originality/valueThis study is the first to examine determinants of financial distress among SMEs operating in Sweden using data from a large-scale longitudinal cross-sectional database.


2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Chao Xiong ◽  
Claudia Stolle ◽  
Patrick Alken ◽  
Jan Rauberg

Abstract In this study, we have derived field-aligned currents (FACs) from magnetometers onboard the Defense Meteorological Satellite Project (DMSP) satellites. The magnetic latitude versus local time distribution of FACs from DMSP shows comparable dependences with previous findings on the intensity and orientation of interplanetary magnetic field (IMF) By and Bz components, which confirms the reliability of DMSP FAC data set. With simultaneous measurements of precipitating particles from DMSP, we further investigate the relation between large-scale FACs and precipitating particles. Our result shows that precipitation electron and ion fluxes both increase in magnitude and extend to lower latitude for enhanced southward IMF Bz, which is similar to the behavior of FACs. Under weak northward and southward Bz conditions, the locations of the R2 current maxima, at both dusk and dawn sides and in both hemispheres, are found to be close to the maxima of the particle energy fluxes; while for the same IMF conditions, R1 currents are displaced further to the respective particle flux peaks. Largest displacement (about 3.5°) is found between the downward R1 current and ion flux peak at the dawn side. Our results suggest that there exists systematic differences in locations of electron/ion precipitation and large-scale upward/downward FACs. As outlined by the statistical mean of these two parameters, the FAC peaks enclose the particle energy flux peaks in an auroral band at both dusk and dawn sides. Our comparisons also found that particle precipitation at dawn and dusk and in both hemispheres maximizes near the mean R2 current peaks. The particle precipitation flux maxima closer to the R1 current peaks are lower in magnitude. This is opposite to the known feature that R1 currents are on average stronger than R2 currents.


Author(s):  
Lior Shamir

Abstract Several recent observations using large data sets of galaxies showed non-random distribution of the spin directions of spiral galaxies, even when the galaxies are too far from each other to have gravitational interaction. Here, a data set of $\sim8.7\cdot10^3$ spiral galaxies imaged by Hubble Space Telescope (HST) is used to test and profile a possible asymmetry between galaxy spin directions. The asymmetry between galaxies with opposite spin directions is compared to the asymmetry of galaxies from the Sloan Digital Sky Survey. The two data sets contain different galaxies at different redshift ranges, and each data set was annotated using a different annotation method. The results show that both data sets show a similar asymmetry in the COSMOS field, which is covered by both telescopes. Fitting the asymmetry of the galaxies to cosine dependence shows a dipole axis with probabilities of $\sim2.8\sigma$ and $\sim7.38\sigma$ in HST and SDSS, respectively. The most likely dipole axis identified in the HST galaxies is at $(\alpha=78^{\rm o},\delta=47^{\rm o})$ and is well within the $1\sigma$ error range compared to the location of the most likely dipole axis in the SDSS galaxies with $z>0.15$ , identified at $(\alpha=71^{\rm o},\delta=61^{\rm o})$ .


Sign in / Sign up

Export Citation Format

Share Document