scholarly journals Towards quantifying the mass extinction debt of the Anthropocene

2021 ◽  
Vol 288 (1949) ◽  
Author(s):  
Christopher Spalding ◽  
Pincelli M. Hull
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Average Rate ◽  
Extinction Debt ◽  
Background Rate ◽  
Extinction Rates ◽  
The Common ◽  
Predictive Metric ◽  
Quantitative Appraisal

To make sense of our present biodiversity crises, the modern rate of species extinctions is commonly compared to a benchmark, or ‘background,’ rate derived from the fossil record. These estimates are critical for bounding the scale of modern diversity loss, but are yet to fully account for the fundamental structure of extinction rates through time. Namely, a substantial fraction of extinctions within the fossil record occurs within relatively short-lived extinction pulses, and not during intervals characterized by background rates of extinction. Accordingly, it is more appropriate to compare the modern event to these pulses than to the long-term average rate. Unfortunately, neither the duration of extinction pulses in the geological record nor the ultimate magnitude of the extinction pulse today is resolved, making assessments of their relative sizes difficult. In addition, the common metric used to compare current and past extinction rates does not correct for large differences in observation duration. Here, we propose a new predictive metric that may be used to ascertain the ultimate extent of the ongoing extinction threat, building on the observation that extinction magnitude in the marine fossil record is correlated to the magnitude of sedimentary turnover. Thus, we propose that the ultimate number of species destined for extinction today can be predicted by way of a quantitative appraisal of humanity's modification of ecosystems as recorded in sediments—that is, by comparing our future rock record with that of the past. The ubiquity of habitat disruption worldwide suggests that a profound mass extinction debt exists today, but one that might yet be averted by preserving and restoring ecosystems and their geological traces.

scholarly journals Accelerated modern human–induced species losses: Entering the sixth mass extinction

2015 ◽  
Vol 1 (5) ◽  
pp. e1400253 ◽  
Author(s):  
Gerardo Ceballos ◽  
Paul R. Ehrlich ◽  
Anthony D. Barnosky ◽  
Andrés García ◽  
Robert M. Pringle ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Average Rate ◽  
Modern Human ◽  
Mass Extinctions ◽  
Rapid Loss ◽  
Background Rate ◽  
Extinction Rates ◽  
Sixth Mass Extinction ◽  
Recent Estimate ◽  
Subsequent Loss

The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

Numerical experiments with model monophyletic and paraphyletic taxa

Paleobiology ◽  
1993 ◽  
Vol 19 (2) ◽  
pp. 168-184 ◽  
Author(s):  
J. John Sepkoski ◽  
David C. Kendrick
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Mass Extinction ◽  
Fossil Record ◽  
Numerical Experiments ◽  
Mass Extinctions ◽  
Diversity Patterns ◽  
Extinction Rates ◽  
Low Levels

The problem of how accurately paraphyletic taxa versus monophyletic (i.e., holophyletic) groups (clades) capture underlying species patterns of diversity and extinction is explored with Monte Carlo simulations. Phylogenies are modeled as stochastic trees. Paraphyletic taxa are defined in an arbitrary manner by randomly choosing progenitors and clustering all descendants not belonging to other taxa. These taxa are then examined to determine which are clades, and the remaining paraphyletic groups are dissected to discover monophyletic subgroups. Comparisons of diversity patterns and extinction rates between modeled taxa and lineages indicate that paraphyletic groups can adequately capture lineage information under a variety of conditions of diversification and mass extinction. This suggests that these groups constitute more than mere “taxonomic noise” in this context. But, strictly monophyletic groups perform somewhat better, especially with regard to mass extinctions. However, when low levels of paleontologic sampling are simulated, the veracity of clades deteriorates, especially with respect to diversity, and modeled paraphyletic taxa often capture more information about underlying lineages. Thus, for studies of diversity and taxic evolution in the fossil record, traditional paleontologic genera and families need not be rejected in favor of cladistically-defined taxa.

scholarly journals Continental faunal exchange and the asymmetrical radiation of carnivores

2015 ◽  
Vol 282 (1817) ◽  
pp. 20151952 ◽  
Author(s):  
Mathias M. Pires ◽  
Daniele Silvestro ◽  
Tiago B. Quental
Keyword(s):  
Climate Change ◽  
North America ◽  
Biological Invasions ◽  
Bayesian Approach ◽  
Fossil Record ◽  
Long Term Outcomes ◽  
Extinction Rates ◽  
Asymmetrical Pattern ◽  
Evolutionary Radiations

Lineages arriving on islands may undergo explosive evolutionary radiations owing to the wealth of ecological opportunities. Although studies on insular taxa have improved our understanding of macroevolutionary phenomena, we know little about the macroevolutionary dynamics of continental exchanges. Here we study the evolution of eight Carnivora families that have migrated across the Northern Hemisphere to investigate if continental invasions also result in explosive diversification dynamics. We used a Bayesian approach to estimate speciation and extinction rates from a substantial dataset of fossil occurrences while accounting for the incompleteness of the fossil record. Our analyses revealed a strongly asymmetrical pattern in which North American lineages invading Eurasia underwent explosive radiations, whereas lineages invading North America maintained uniform diversification dynamics. These invasions into Eurasia were characterized by high rates of speciation and extinction. The radiation of the arriving lineages in Eurasia coincide with the decline of established lineages or phases of climate change, suggesting differences in the ecological settings between the continents may be responsible for the disparity in diversification dynamics. These results reveal long-term outcomes of biological invasions and show that the importance of explosive radiations in shaping diversity extends beyond insular systems and have significant impact at continental scales.

The foundations of peaceful coexistence after the war ... Mosul is a model

2019 ◽  
pp. 178
Author(s):  
Omar Hashim Thanon
Keyword(s):  
Ethnic Diversity ◽  
Psychological Consequences ◽  
Peaceful Coexistence ◽  
Negative Effects ◽  
Mass Displacement ◽  
The Common ◽  
Near Term ◽  
Post War ◽  
Common Destiny

Since peaceful coexistence reflects in its various aspects the concept of harmony between the members of the same society with their different national, religious and sectarian affiliations, as well as their attitudes and ideas, what brings together these are the common bonds such as land, interests and common destiny. But this coexistence is exposing for crises and instability and the theft of rights and other that destroy the communities with their different religious, national, sectarian, ethnic aspects, especially if these led to a crisis of fighting or war, which produces only destruction and mass displacement, ttherefore, the process of bridging the gap between the different parts of society in the post-war phase through a set of requirements that serve as the basis for the promotion of peaceful coexistence within the same country to consolidate civil and community peace in order to create a general framework and a coherent basis to reconstruct the community again.      Hence the premise of the research by asking about the extent of the possibility and ability of the community of religious and ethnic diversity, which has been exposed to these crises, which aimed at this diversity, basically to be able to rise and re-integrate within the same country and thus achieve civil and community peace, and Mosul is an example for that, the negative effects of the war and the accomplices of many criminal acts have given rise to hatred and fear for all, leading to the loss of livelihoods, which in the long term may have devastating social and psychological consequences.        To clarify all of this, the title of the first topic was a review of the concept and origin of peaceful coexistence. While the second topic dealt with the requirements of peaceful coexistence and social integration in Mosul, the last topic has identified the most important challenges facing the processes of coexistence and integration in Mosul. All this in order to paint a better future for the conductor at all levels in the near term at the very least to achieve the values of this peaceful coexistence, especially in the post-war period.

Hemorrhoidal Laser procedure (HeLP) and Hemorrrrhoidal Laser procedure + mucopexy (HeLPexx) and other Emerging Technologies

2020 ◽  
Vol 15 ◽  
Author(s):  
Paolo Giamundo
Keyword(s):  
Laser Treatment ◽  
Dentate Line ◽  
Mucosal Prolapse ◽  
Daily Activities ◽  
Common Goal ◽  
Superior Rectal Artery ◽  
Doppler Probe ◽  
The Common ◽  
Probe Set

Background: Minimally-invasive treatments for hemorrhoids should be encouraged as they cause low morbidity, reasonable discomfort and quicker return to work. According to the “vascular theory” hemorrhoidal disease is mainly caused by blood overflow into hemorrhoidal plexus deriving from the superior hemorrhoidal arteries. Introduction: Many different procedures have been described in the literature with the common goal of reducing the blood flow into the hemorrhoidal piles. ‘HeLP’ (Hemorrhoids Laser Procedure) is a novel form of dearterialization to treat patients suffering from symptomatic hemorrhoids. Methods: The procedure consists of the closure of the terminal branches of the superior rectal artery approximately 2-3 cm above the dentate line by means of laser shots originated by a diode laser platform. The arteries, at that level, have variable location and distribution. Therefore, a doppler probe set at the frequency of 20MHz helps identifying the arteries that would be missed otherwise. The laser beam is well tolerated by patients. For this reason, anesthesia is not required in most cases and the procedure allows a quick return to daily activities. In case of concomitant severe mucosal prolapse, the laser treatment can be combined with suture mucopexy. Three to six running sutures allow a complete lifting of hemorrhoidal piles, securing long-term resolution of symptoms. Results and Conclusions: ‘HeLP’ is indicated in patients with symptomatic hemorrhoids where conservative treatment failed and when mucosal prolapse is scarce or not symptomatic. The addition of mucopexy to laser treatment (HeLPexx) contributes to overall resolution of symptoms when mucosal prolapse is an issue, Emborrhoid is another novel, ‘hi-tech’ form of selective dearterialization used in selected case of hemorrhoids where main symptom is bleeding. It is generally used in cases where surgery is contraindicated due to severe concomitant diseases.

The Co-Occurrence of Autism and Gender Diversity

2020 ◽  
pp. 197-211
Author(s):  
Jill C. Fodstad ◽  
Rebecca Elias ◽  
Shivali Sarawgi
Keyword(s):  
Gender Dysphoria ◽  
Gender Diversity ◽  
Gender Nonconforming ◽  
Medical Interventions ◽  
Gender Diverse ◽  
Nonbinary Gender ◽  
Psychiatric Conditions ◽  
The Common ◽  
And Gender

Gender diversity refers to gender expressions and/or gender identity experiences that vary from the common experiences of gender. Gender-diverse people may be gender nonconforming, gender nonbinary, gender fluid, gender exploring, transgender, and so forth. Some gender-diverse individuals experience gender dysphoria and/or gender incongruence and may require gender-affirming supports, including gender-affirming medical interventions. The co-occurrence of autism and gender diversity has been highlighted in a series of studies internationally as well as through rich community expressions. Studies in gender-referred individuals reveal high rates of autism traits as well as high rates of existing autism diagnoses. Studies in autistic populations reveal greater gender diversity characteristics. The long-term course of gender diversity in autistic individuals is poorly understood. Clinical guidelines have been developed for adolescents with the co-occurrence, but much work remains: No gender-related measures have been developed and tested for use in neurodiverse populations, no programs exist to support gender-diverse neurodiverse adults, and little is known about co-occurring mental health profiles, risks, or protective factors for people with the co-occurrence. The inclusion of this chapter on co-occurring autism and gender diversity within a book on “co-occurring psychiatric conditions” is problematic, because gender diversity is not a “psychiatric condition,” but instead a form of human diversity. The diagnosis of Gender Dysphoria is useful only insomuch as it allows individuals to obtain necessary gender-related supports. The authors’ choice to include this chapter in this book reflects a compromise, motivated by the need for educating both autism and gender specialists in this common co-occurrence.

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

Ultrasonic Percutaneous Tenotomy for Recalcitrant Lateral Elbow Tendinopathy: Clinical and Sonographic Results at 90 Months

2021 ◽  
pp. 036354652110101
Author(s):  
Benjamin F.H. Ang ◽  
P. Chandra Mohan ◽  
Meng Ai Png ◽  
John Carson Allen ◽  
Tet Sen Howe ◽  
...  
Keyword(s):  
Pain Relief ◽  
Extensor Tendon ◽  
Tissue Healing ◽  
Lateral Elbow ◽  
Percutaneous Tenotomy ◽  
Vas Scores ◽  
The Common ◽  
Lateral Elbow Tendinopathy

Background: In a study from our institution, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon for recalcitrant lateral elbow tendinopathy showed excellent safety profiles, high tolerability, efficiency, sustained pain relief, functional improvement, and sonographic evidence of tissue healing in 20 patients at 3 years’ follow-up. Purpose: To explore the long-term clinical and sonographic results of ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon. Study Design: Case series; Level of evidence, 4. Methods: The same cohort of 20 patients was recalled after 7 years, and visual analog scale (VAS) for pain and Disabilities of the Arm, Shoulder and Hand (DASH) scores, need for secondary intervention, and overall satisfaction were assessed. They were also reassessed using ultrasound imaging of the brevis and the common extensor tendon to evaluate tendon hypervascularity, tendon thickness, and the progress or the recurrence of the hypoechoic scar tissue. Results: We successfully scored 19 patients and performed ultrasound on 16 patients with a median follow-up of 90 months (range, 86-102 months). There were no adverse outcomes and satisfaction remained at 100% (6 patients, satisfied; 13 patients, very satisfied). No patient developed a recurrence of symptoms and signs of lateral elbow tendinopathy, and therefore no secondary intervention was required. The improvement from baseline and early term scores was sustained ( P < .001 for all). At 90 months, there was a significant improvement in VAS scores and DASH–Compulsory scores compared with preprocedure scores and all follow-up times until 3 months. There was no difference in VAS scores and DASH–Compulsory scores at 90 months compared with 6 and 36 months. For DASH–Work scores, there was a significant improvement at 90 months compared with preprocedure scores, but there was no difference between DASH–Work scores at 90 months and scores at all other points of follow-up. At 90 months, hypervascularity remained resolved in 79% of patients, while all patients had reduced tendon swelling and sustained resolution or reduction of the hypoechoic lesion. Conclusion: At the long-term follow-up of 90 months, ultrasonic percutaneous tenotomy of the brevis and the common extensor tendon, previously shown to enhance recovery of lateral elbow tendinopathy, demonstrated good durability of pain relief and functional recovery that was previously achieved. This was accompanied by sustained sonographic tissue healing with no significant deterioration.

scholarly journals Current extinction rate in European freshwater gastropods greatly exceeds that of the late Cretaceous mass extinction

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas A. Neubauer ◽  
Torsten Hauffe ◽  
Daniele Silvestro ◽  
Jens Schauer ◽  
Dietrich Kadolsky ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Recovery Period ◽  
Freshwater Ecosystems ◽  
Extinction Rate ◽  
Freshwater Gastropods ◽  
Extinction Rates ◽  
Freshwater Biota ◽  
Order Of Magnitude ◽  
To Come ◽  
Mass Extinction Event

AbstractThe Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. However, previous studies based on vertebrates suggest that freshwater biota were much less affected. Here we assemble a time series of European freshwater gastropod species occurrences and inferred extinction rates covering the past 200 million years. We find that extinction rates increased by more than one order of magnitude during the Cretaceous–Paleogene mass extinction, which resulted in the extinction of 92.5% of all species. The extinction phase lasted 5.4 million years and was followed by a recovery period of 6.9 million years. However, present extinction rates in European freshwater gastropods are three orders of magnitude higher than even these revised estimates for the Cretaceous–Paleogene mass extinction. Our results indicate that, unless substantial conservation effort is directed to freshwater ecosystems, the present extinction crisis will have a severe impact to freshwater biota for millions of years to come.

scholarly journals Acute symptoms of mild to moderate COVID-19 are highly heterogeneous across individuals and over time

2021 ◽  
Author(s):  
Thomas L Rodebaugh ◽  
Madelyn R Frumkin ◽  
Angela M Reiersen ◽  
Eric J Lenze ◽  
Michael S Avidan ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Survey Methods ◽  
Clinical Care ◽  
Clinical Deterioration ◽  
Symptom Profiles ◽  
Fluctuating Course ◽  
The Common ◽  
Symptom Changes ◽  
Over Time

Abstract Background The symptoms of COVID-19 appear to be heterogenous, and the typical course of these symptoms is unknown. Our objectives were to characterize the common trajectories of COVID-19 symptoms and assess how symptom course predicts other symptom changes as well as clinical deterioration. Methods 162 participants with acute COVID-19 responded to surveys up to 31 times for up to 17 days. Several statistical methods were used to characterize the temporal dynamics of these symptoms. Because nine participants showed clinical deterioration, we explored whether these participants showed any differences in symptom profiles. Results Trajectories varied greatly between individuals, with many having persistently severe symptoms or developing new symptoms several days after being diagnosed. A typical trajectory was for a symptom to improve at a decremental rate, with most symptoms still persisting to some degree at the end of the reporting period. The pattern of symptoms over time suggested a fluctuating course for many patients. Participants who showed clinical deterioration were more likely to present with higher reports of severity of cough and diarrhea. Conclusion The course of symptoms during the initial weeks of COVID-19 is highly heterogeneous and is neither predictable nor easily characterized using typical survey methods. This has implications for clinical care and early-treatment clinical trials. Additional research is needed to determine whether the decelerating improvement pattern seen in our data is related to the phenomenon of patients reporting long-term symptoms, and whether higher symptoms of diarrhea in early illness presages deterioration.

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