The Anthropocene Mass Extinction: An Emerging Curriculum Theme for Science Educators

2011 ◽  
Vol 73 (2) ◽  
pp. 78-83 ◽  
Author(s):  
Ron Wagler
Keyword(s):  
Human Activities ◽  
Mass Extinction ◽  
Science Curriculum ◽  
Habitat Modification ◽  
Mass Extinctions ◽  
Sixth Mass Extinction ◽  
History Of ◽  
Science Educators ◽  
Curriculum Topics ◽  
Great Mass

There have been five past great mass extinctions during the history of Earth. There is an ever-growing consensus within the scientific community that we have entered a sixth mass extinction. Human activities are associated directly or indirectly with nearly every aspect of this extinction. This article presents an overview of the five past great mass extinctions; an overview of the current Anthropocene mass extinction; past and present human activities associated with the current Anthropocene mass extinction; current and future rates of species extinction; and broad science-curriculum topics associated with the current Anthropocene mass extinction that can be used by science educators. These broad topics are organized around the major global, anthropogenic direct drivers of habitat modification, fragmentation, and destruction; overexploitation of species; the spread of invasive species and genes; pollution; and climate change.

scholarly journals The most important message in the history of mankind

2016 ◽  
Vol 4 (2) ◽  
pp. 26-33
Author(s):  
Piotr Skubała
Keyword(s):  
Human Activities ◽  
Natural Capital ◽  
Biodiversity Loss ◽  
Negative Influence ◽  
Mass Extinctions ◽  
The Earth ◽  
Important Message ◽  
Sixth Mass Extinction ◽  
History Of ◽  
The Impact

AbstractIt the long history of life on the Earth five major mass extinctions were observed. Nowadays, the impact of human activities on the planet has accelerated the loss of species and ecosystems to a level comparable to a sixth mass extinction, the first driven by a living species. Surprisingly, this fact rarely reaches the public consciousness. The negative influence of human activity is observed in whole area of land ecosystems, whereas marine ecosystems are at risk of entering a phase of extinction unprecedented in human history. We have domesticated landscapes and ecosystems causing unforeseen changes in ecosystem attributes. Humanity has already overshot global biocapacity by 50% and now lives unsustainabily by depleting stocks of natural capital. Three the Earth-system processes - climate change, rate of biodiversity loss and interference with the nitrogen cycle - have already transgressed their boundaries. Human activities are of sufficient magnitude to suggest that we have triggered a new geological epoch, the Anthropocene. The “Biosphere 2” project revailed that we are not able to build and control a different system life and that we are totally dependent on the present biosphere. The experiment known in the literature as “The Tragedy of the Commons” reminds us that we need frugality and cooperation to solve environmental problems and survive.

scholarly journals Characteristic disruptions of an excitable carbon cycle

2019 ◽  
Vol 116 (30) ◽  
pp. 14813-14822 ◽  
Author(s):  
Daniel H. Rothman
Keyword(s):  
Mathematical Model ◽  
Carbon Cycle ◽  
Mass Extinction ◽  
Rate Of Change ◽  
Stable Steady State ◽  
Mass Extinctions ◽  
Carbon Mass ◽  
History Of ◽  
External Sources ◽  
Major Disruption

The history of the carbon cycle is punctuated by enigmatic transient changes in the ocean’s store of carbon. Mass extinction is always accompanied by such a disruption, but most disruptions are relatively benign. The less calamitous group exhibits a characteristic rate of change whereas greater surges accompany mass extinctions. To better understand these observations, I formulate and analyze a mathematical model that suggests that disruptions are initiated by perturbation of a permanently stable steady state beyond a threshold. The ensuing excitation exhibits the characteristic surge of real disruptions. In this view, the magnitude and timescale of the disruption are properties of the carbon cycle itself rather than its perturbation. Surges associated with mass extinction, however, require additional inputs from external sources such as massive volcanism. Surges are excited when CO2 enters the oceans at a flux that exceeds a threshold. The threshold depends on the duration of the injection. For injections lasting a time ti≳10,000 y in the modern carbon cycle, the threshold flux is constant; for smaller ti, the threshold scales like ti−1. Consequently the unusually strong but geologically brief duration of modern anthropogenic oceanic CO2 uptake is roughly equivalent, in terms of its potential to excite a major disruption, to relatively weak but longer-lived perturbations associated with massive volcanism in the geologic past.

scholarly journals Diversification events and the effects of mass extinctions on Crocodyliformes evolutionary history

2015 ◽  
Vol 2 (5) ◽  
pp. 140385 ◽  
Author(s):  
Mario Bronzati ◽  
Felipe C. Montefeltro ◽  
Max C. Langer
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Evolutionary History ◽  
Continuous Process ◽  
Mass Extinctions ◽  
Terrestrial Habitats ◽  
History Of ◽  
The Rich ◽  
A Minor ◽  
Diversification Event

The rich fossil record of Crocodyliformes shows a much greater diversity in the past than today in terms of morphological disparity and occupation of niches. We conducted topology-based analyses seeking diversification shifts along the evolutionary history of the group. Our results support previous studies, indicating an initial radiation of the group following the Triassic/Jurassic mass extinction, here assumed to be related to the diversification of terrestrial protosuchians, marine thalattosuchians and semi-aquatic lineages within Neosuchia. During the Cretaceous, notosuchians embodied a second diversification event in terrestrial habitats and eusuchian lineages started diversifying before the end of the Mesozoic. Our results also support previous arguments for a minor impact of the Cretaceous/Palaeogene mass extinction on the evolutionary history of the group. This argument is not only based on the information from the fossil record, which shows basal groups surviving the mass extinction and the decline of other Mesozoic lineages before the event, but also by the diversification event encompassing only the alligatoroids in the earliest period after the extinction. Our results also indicate that, instead of a continuous process through time, Crocodyliformes diversification was patchy, with events restricted to specific subgroups in particular environments and time intervals.

scholarly journals Thinking about the Biodiversity Loss in This Changing World

Geosciences ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 370
Author(s):  
Maria Rita Palombo
Keyword(s):  
Big Five ◽  
Mass Extinction ◽  
Negative Impact ◽  
Biodiversity Loss ◽  
Wildlife Trade ◽  
Ecosystem Structure ◽  
Extinction Rate ◽  
Mass Extinctions ◽  
Species Introduction ◽  
Sixth Mass Extinction

Extinction of species has been a recurrent phenomenon in the history of our planet, but it was generally outweighed in the course of quite a long geological time by the appearance of new species, except, especially, for the five geologically short times when the so-called “Big Five” mass extinctions occurred. Could the current decline in biodiversity be considered as a signal of an ongoing, human-driven sixth mass extinction? This note briefly examines some issues related to: (i) The hypothesized current extinction rate and the magnitude of contemporary global biodiversity loss; (ii) the challenges of comparing them to the background extinction rate and the magnitude of the past Big Five mass extinction events; (iii) briefly considering the effects of the main anthropogenic stressors on ecosystems, including the risk of the emergence of pandemic diseases. A comparison between the Pleistocene fauna dynamics with the present defaunation process and the cascading effects of recent anthropogenic actions on ecosystem structure and functioning suggests that habitat degradation, ecosystem fragmentation, and alien species introduction are important stressors increasing the negative impact on biodiversity exerted by anthropogenic-driven climate changes and their connected effects. In addition, anthropogenic ecological stressors such as urbanization, landscapes, and wildlife trade, creating new opportunities for virus transmission by augmenting human contact with wild species, are among the main factors triggering pandemic diseases.

scholarly journals Hopeful Extinctions? Tesla, Technological Solutionism and the Anthropocene

2018 ◽  
Vol 10 (2) ◽  
pp. 163-184
Author(s):  
Sy Taffel
Keyword(s):  
Human Activity ◽  
Mass Extinction ◽  
Technological Progress ◽  
The Other ◽  
Mass Extinctions ◽  
Geological Record ◽  
Sixth Mass Extinction ◽  
The One ◽  
Ecological Catastrophe

Over thirty years since Jean-Francois Lyotard declared the death of metanarratives, we currently find two apparently incompatible discourses that dominate imagined planetary futures. On the one hand, we encounter a metanarrative of technological progress has been fuelled by decades of advances in computational, networked, mobile and pervasive technologies. On the other, we find the apocalyptic discourse of the Anthropocene, whereby human activity is understood to be responsible for precipitating the sixth mass extinction of life in Earth’s geological record. This paper explores how the divergent futures of technological solutionism and ecological catastrophism encounter one another, focusing on Tesla as a case study where technological consumerism is posited as the solution to ecological catastrophe. Critically examining the materiality of digital technoculture challenges the immaterialist rhetoric of technological solutionism that permeates both neoliberal and leftist discourses of automation, whilst questioning the ‘we’ that is implicit in the problematic universalisation of Anthropocenic catastrophism, instead pointing to the deeply entrenched inequalities that perpetuate networked capitalism. Ultimately, the paper asks whether it is possible to move beyond bleak claims that we must simply “work within our disorientation and distress to negotiate life in human-damaged environments” (Tsing 2015: 131), to assemble the fragile hope that Goode and Godhe (2017) argue is necessary to move beyond capitalist realism. Hope suggests an optimism that sits uncomfortably with the reality of mass extinctions, however, the scale of the ecological crises means that we cannot afford the fatalism associated with losing hope.

scholarly journals Are Insects Heading Toward Their First Mass Extinction? Distinguishing Turnover From Crises in Their Fossil Record

2020 ◽  
Author(s):  
Sandra R Schachat ◽  
Conrad C Labandeira
Keyword(s):  
Mass Extinction ◽  
Fossil Record ◽  
Taxonomic Diversity ◽  
Insect Diversity ◽  
Mass Extinctions ◽  
Sudden Loss ◽  
Faunal Turnover ◽  
Sixth Mass Extinction ◽  
Extinction Event ◽  
Permian Extinction

Abstract Time and again, over hundreds of millions of years, environmental disturbances have caused mass extinctions of animals ranging from reptiles to corals. The anthropogenic loss of species diversity happening now is often discussed as the ‘sixth mass extinction’ in light of the ‘Big Five’ mass extinctions in the fossil record. But insects, whose taxonomic diversity now appears to be threatened by human activity, have a unique extinction history. Prehistoric losses of insect diversity at the levels of order and family appear to have been driven by competition among insect lineages, with biotic replacement ensuring minimal net losses in taxonomic diversity. The end-Permian extinction, the ‘mother of mass extinctions’ in the seas, was more of a faunal turnover than a mass extinction for insects. Insects’ current biotic crisis has been measured in terms of the loss of abundance and biomass (rather than the loss of species, genera, or families) and these are essentially impossible to measure in the fossil record. However, should the ongoing loss of insect abundance and biomass cause the demise of many insect families, the current extinction event may well be the first sudden loss of higher-level insect diversity in our planet’s history. This is not insects’ sixth mass extinction—in fact, it may become their first.

Morphologic and taxonomic history of Paleozoic ammonoids in time and morphospace

Paleobiology ◽  
2008 ◽  
Vol 34 (1) ◽  
pp. 128-154 ◽  
Author(s):  
W. B. Saunders ◽  
Emily Greenfest-Allen ◽  
David M. Work ◽  
S. V. Nikolaeva
Keyword(s):  
Mass Extinction ◽  
Evolutionary History ◽  
Large Scale ◽  
Taxonomic Diversity ◽  
Mass Extinctions ◽  
History Of ◽  
Morphologic Variation ◽  
Components Analysis ◽  
Extinction Events ◽  
Mass Extinction Events

Principal components analysis (PCA) of 21 shell parameters (geometry, sculpture, aperture shape, and suture complexity) in 597 L. Devonian to L. Triassic ammonoid genera (spanning ~166 Myr) shows that eight basic morphotypes appeared within ~20 Myr of the first appearance of ammonoids. With one exception, these morphotypes persisted throughout the Paleozoic, occurring in ~75% of the ~5-Myr time bins used in this study. Morphotypes were not exclusive to particular lineages. Their persistence was not just a product of phylogenetic constraints or longevity, and multiple iterations of the same morphotypes occurred at different times and in different groups. Although mass extinction events severely condensed the range of morphologic variation and taxonomic diversity, the effects were short lived and most extinct morphotypes were usually iterated within 5 Myr. The most important effect of mass extinctions on ammonoid evolutionary history seems to have been their role in large scale taxonomic turnovers; they effectively eliminated previously dominant orders at the Frasnian/Famennian (F/F) (Agoniatitida), the Devonian/Mississippian (D/M) (Clymeniida), and the Permian/Triassic (P/T) (Goniatitida and Prolecanitida) extinctions. Survivors varied from two (P/T) to four (D/M) and five genera (F/F). These events generated sharp reductions in morphologic disparity at the D/M (58%) and at the P/T (59%), but there was a net increase at the F/F (38%). There was no obvious survival bias for particular morphotypes, but 64% are interpreted to have beenNautilus-like nektobenthic. The recurrence of particular combinations of morphology and their strong independence of phylogeny are strong arguments for functional constraint. Intervals between mass extinctions seem to have been relatively static in terms of morphotype numbers, in contrast to numbers of genera. Significant decreases in genus diversity (54%) and morphologic disparity (33%) commenced in the mid-Permian (Wordian/Capitanian boundary), well before the final P/T event.

scholarly journals Did a gamma-ray burst initiate the late Ordovician mass extinction?

2004 ◽  
Vol 3 (1) ◽  
pp. 55-61 ◽  
Author(s):  
A.L. Melott ◽  
B.S. Lieberman ◽  
C.M. Laird ◽  
L.D. Martin ◽  
M.V. Medvedev ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Gamma Ray ◽  
Late Ordovician ◽  
Mass Extinctions ◽  
Solar Ultraviolet Radiation ◽  
Observable Universe ◽  
The Earth ◽  
Global Cooling ◽  
History Of ◽  
Solar Ultraviolet

Gamma-ray bursts (GRBs) produce a flux of radiation detectable across the observable Universe. A GRB within our own galaxy could do considerable damage to the Earth's biosphere; rate estimates suggest that a dangerously near GRB should occur on average two or more times per billion years. At least five times in the history of life, the Earth has experienced mass extinctions that eliminated a large percentage of the biota. Many possible causes have been documented, and GRBs may also have contributed. The late Ordovician mass extinction approximately 440 million years ago may be at least partly the result of a GRB. A special feature of GRBs in terms of terrestrial effects is a nearly impulsive energy input of the order of 10 s. Due to expected severe depletion of the ozone layer, intense solar ultraviolet radiation would result from a nearby GRB, and some of the patterns of extinction and survivorship at this time may be attributable to elevated levels of UV radiation reaching the Earth. In addition, a GRB could trigger the global cooling which occurs at the end of the Ordovician period that follows an interval of relatively warm climate. Intense rapid cooling and glaciation at that time, previously identified as the probable cause of this mass extinction, may have resulted from a GRB.

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.

scholarly journals The future of the oceans past

2010 ◽  
Vol 365 (1558) ◽  
pp. 3765-3778 ◽  
Author(s):  
Jeremy B. C. Jackson
Keyword(s):  
Ocean Acidification ◽  
Deep Sea ◽  
Mass Extinction ◽  
Mass Extinctions ◽  
Conservation Action ◽  
Isthmus Of Panama ◽  
Geological Past ◽  
History Of ◽  
Short Time ◽  
Oceanographic Conditions

Major macroevolutionary events in the history of the oceans are linked to changes in oceanographic conditions and environments on regional to global scales. Even small changes in climate and productivity, such as those that occurred after the rise of the Isthmus of Panama, caused major changes in Caribbean coastal ecosystems and mass extinctions of major taxa. In contrast, massive influxes of carbon at the end of the Palaeocene caused intense global warming, ocean acidification, mass extinction throughout the deep sea and the worldwide disappearance of coral reefs. Today, overfishing, pollution and increases in greenhouse gases are causing comparably great changes to ocean environments and ecosystems. Some of these changes are potentially reversible on very short time scales, but warming and ocean acidification will intensify before they decline even with immediate reduction in emissions. There is an urgent need for immediate and decisive conservation action. Otherwise, another great mass extinction affecting all ocean ecosystems and comparable to the upheavals of the geological past appears inevitable.

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