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Page 1: Human Impact on Biodiversity Writing Task Human Impact … · Human Impact on Biodiversity Writing Task . Human Impact Topics: ... (L2) Makes no mention of counter ... we are also

Human Impact on Biodiversity Writing Task Human Impact Topics:

Coral Bleaching Deforestation Desertification Eutrophication Fossil Fuels & Climate Change Habitat Fragmentation Invasive Species Overexploitation of Wildlife & Plants Poaching

Your first task is to locate a reputable scientific article on your assigned topic. You must cite this source within the text of your essay. You will then complete the following two tasks. Essay Assignment (21 total pts – See attached rubric): Question: Do humans have an ethical responsibility and/or moral obligation to preserve biodiversity? After reading the four attached articles on biodiversity and a reputable scientific article on your assigned human impact topic, write a 3-paragraph essay in which you discuss the cause(s) of the current decline in biodiversity and explain the effect(s) that your assigned human impact is having on this event. Support your discussion with evidence from the article(s). Give two (2) examples from past or current events to illustrate and clarify your position. Guidelines:

• Your paper must be typed, double-spaced, and no longer than 2 pages. • Include your name and hour at the top right corner of the first page. • You must cite at least two of the three articles in your discussion. • Use parenthetical citations to cite the sources within the text of your writing. • At the end of your essay, include the bibliographic information for your chosen scientific resource.

Due Date: Friday, May 13th

Discussion Assignment (9 total pts -3 pts per relevant post): Go online and discuss your assigned human impact topic on the page that has been created for your topic. You are required to create at least three separate posts. Your first post should be a paragraph summarizing the claim you made in your essay. Your remaining posts must be specifically identified as one of the following:

Rebuttal A statement of an opposing viewpoint that a claim is wrong, invalid, or unacceptable with an explanation using evidence and reasoning

Counterargument An alternative argument for the claim based on fact, data, theory, opinion, or other forms of reasoning

New Question A statement suggesting another question that should be investigated related to the original claim

Due Date: Monday, May 16th

Tips:

• Before forming an opinion, carefully consider all sides of the issue, including ecological, economic, political, and social impacts.

• Be sure you deeply understand the significance of biodiversity on a global scale and how a decline in biodiversity might impact local environments.

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LDC Template Task Collection Version 2.0 • © Literacy Design Collaborative, 2013 Page 8

Argumentation Teaching Task Rubric for Template Task Collection Version 2.0

Scoring Elements

Not Yet Approaches Expectations Meets Expectations Advanced 1 1.5 2 2.5 3 3.5 4

Focus Attempts to address prompt, but lacks focus or is off-task.

Addresses prompt appropriately and establishes a position, but

focus is uneven.

Addresses prompt appropriately and maintains a clear, steady focus. Provides a generally convincing

position.

Addresses all aspects of prompt

appropriately with a consistently strong focus and convincing position.

Controlling Idea

Attempts to establish a claim, but lacks a clear purpose. (L2) Makes no mention of counter

claims.

Establishes a claim. (L2) Makes note of counter claims.

Establishes a credible claim. (L2) Develops claim and counter claims

fairly.

Establishes and maintains a substantive and credible claim or proposal. (L2)

Develops claims and counter claims fairly and thoroughly.

Reading/ Research

Attempts to reference reading materials to develop response,

but lacks connections or relevance to the purpose of the

prompt.

Presents information from reading materials relevant to the

purpose of the prompt with minor lapses in accuracy or

completeness.

Accurately presents details from reading materials relevant to the

purpose of the prompt to develop argument or claim.

Accurately and effectively presents

important details from reading materials to develop argument or claim.

Development

Attempts to provide details in response to the prompt, but

lacks sufficient development or relevance to the purpose of the

prompt. (L3) Makes no connections or a connection

that is irrelevant to argument or claim.

Presents appropriate details to support and develop the focus, controlling idea, or claim, with minor lapses in the reasoning, examples, or explanations. (L3)

Makes a connection with a weak or unclear relationship to

argument or claim.

Presents appropriate and sufficient details to support and develop the

focus, controlling idea, or claim. (L3) Makes a relevant connection to clarify

argument or claim.

Presents thorough and detailed information to effectively support and develop the focus, controlling idea, or

claim. (L3) Makes a clarifying connection(s) that illuminates argument

and adds depth to reasoning.

Organization Attempts to organize ideas, but lacks control of structure.

Uses an appropriate organizational structure for

development of reasoning and logic, with minor lapses in

structure and/or coherence.

Maintains an appropriate organizational structure to address

specific requirements of the prompt. Structure reveals the reasoning and

logic of the argument.

Maintains an organizational structure that intentionally and effectively enhances the presentation of information as required

by the specific prompt. Structure enhances development of the reasoning

and logic of the argument.

Conventions

Attempts to demonstrate standard English conventions,

but lacks cohesion and control of grammar, usage, and

mechanics. Sources are used without citation.

Demonstrates an uneven command of standard English

conventions and cohesion. Uses language and tone with

some inaccurate, inappropriate, or uneven features.

Inconsistently cites sources.

Demonstrates a command of standard English conventions and cohesion, with few errors. Response includes language and tone appropriate to the audience, purpose, and specific requirements of

the prompt. Cites sources using appropriate format with only minor

errors.

Demonstrates and maintains a well-developed command of standard English

conventions and cohesion, with few errors. Response includes language and

tone consistently appropriate to the audience, purpose, and specific requirements of the prompt.

Consistently cites sources using appropriate format.

Content Understanding

Attempts to include disciplinary content in argument, but

understanding of content is weak; content is irrelevant,

inappropriate, or inaccurate.

Briefly notes disciplinary content relevant to the prompt; shows basic or uneven understanding

of content; minor errors in explanation.

Accurately presents disciplinary content relevant to the prompt with

sufficient explanations that demonstrate understanding.

Integrates relevant and accurate disciplinary content with thorough

explanations that demonstrate in-depth understanding.

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Extinction Rates Are Biased And Much Worse Than You Thought The IUCN's Red List of endangered species looks bad, but the reality is probably much, much worse By Rachel Nuwer SMITHSONIAN.COM SEPTEMBER 3, 2012 Human activity—mostly habitat destruction and overhunting—has obliterated nearly 900 species over the past 500 years. Around 17,000 plants and animals are listed today on the International Union for the Conservation of Nature (IUCN) Red List of endangered species. According to the IUCN, one in eight birds, one in four mammals, one in five invertebrates, one in three amphibians and half of all turtles face extinction. The Guardian produced this guilt-inducing map showing how the world’s countries fare when it comes to extinction counts:

For U.S. citizens, this looks particularly bad, while those in Vietnam, Kazakistan and Paraguay come off as innocent protectors of local wildlife. However, this map is inherently biased. These are only documented extinctions, after all. While the U.S. is undoubtedly skilled at bulldozing wetlands to build shopping malls and shooting passenger pigeons into extinction just for fun, we are also exceptionally good at book-keeping. “It is widely suspected that IUCN accounts of species vulnerability are biased toward the better-studied taxonomic groups of the western world,” scientists dryly write in the journal Conservation Biology. In other words, the West is doing a poor job of saving species, but the rest of the planet likely is, too. Here, the Guardian provides a map of extinct (red) versus critically endangered (yellow) species by regions:

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Now, things are starting to even out a bit. Species at imminent risk of extinction tend to cluster in the tropics—South America, Southeast Asia and Sub-Saharan Africa—where high biodiversity is often coupled with deforestation and overhunting. Unfortunately, however, this map still shows only a very biased slice of the pie. Research tends to focus on the big, the cuddly and the beautiful. Plenty of research is done on polar bears and tigers, but how about dung beetles and fungi, mollusks and mites? In addition to the geographic bias, this species bias also skews the data. An editorial piece from the nonprofit Bat Conservation International elaborates:

The IUCN red list has a substantial geographic bias toward North American species. Far from reflecting reality, the red list reflects our ignorance regarding the status of most species. We simply have more knowledge about the status of bats in North America than we do for most other parts of the world. In fact, our ignorance is so extreme that we are not even certain how accurate the IUCN list is for many North American species. We simply do not have the data to determine whether they are stable, increasing or decreasing, and at what rates. Given this lack of information and the fact that most bats investigated are declining, the IUCN red list gives an inaccurate and minimal assessment of the current crisis.

The IUCN is also quick to point out its own shortcomings:

The number of documented extinctions (844 species since 1500 AD) grossly underrepresents the number of extinctions that have taken place in historic times, due to very incomplete and uneven sampling, both geographically and taxonomically. An additional 208 species could already be Extinct, but further information is required to confirm this. Data from the IUCN Red List indicate a current extinction rate that is at least two, and probably three, orders of magnitude higher than the background rate typical over the planet’s geological history. Very little is known about marine and freshwater extinctions, but preliminary evidence from North America indicates a very high level of extinctions in freshwater habitats. Although information is still very limited, there is growing evidence that marine species are less resilient to extinction in the face of threats than was once thought. Although the island species have experienced the greatest number of extinctions in historic times, continental extinctions are becoming more frequent, and account for almost 50% of the extinctions confirmed over the last 20 years.

The values shown on those already dismal maps should likely be three times higher than what’s reported, and regardless of whether we know about it, creatures are blinking out all over the planet, all of the time.

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Extinctions During Human Era One Thousand Times More Than Before From Brown University Science Daily SEPTEMBER 2, 2014 The gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times. It's hard to comprehend how bad the current rate of species extinction around the world has become without knowing what it was before people came along. The newest estimate is that the pre-human rate was 10 times lower than scientists had thought, which means that the current level is 10 times worse. Extinctions are about 1,000 times more frequent now than in the 60 million years before people came along. The explanation from lead author Jurriaan de Vos, a Brown University postdoctoral researcher, senior author Stuart Pimm, a Duke University professor, and their team appears online in the journal Conservation Biology. "This reinforces the urgency to conserve what is left and to try to reduce our impacts," said de Vos, who began the work while at the University of Zurich. "It was very, very different before humans entered the scene." In absolute, albeit rough, terms the paper calculates a "normal background rate" of extinction of 0.1 extinctions per million species per year. That revises the figure of 1 extinction per million species per year that Pimm estimated in prior work in the 1990s. By contrast, the current extinction rate is more on the order of 100 extinctions per million species per year. Orders of magnitude, rather than precise numbers are about the best any method can do for a global extinction rate, de Vos said. "That's just being honest about the uncertainty there is in these type of analyses." From fossils to genetics The new estimate improves markedly on prior ones mostly because it goes beyond the fossil record. Fossils are helpful sources of information, but their shortcomings include disproportionate representation of hard-bodied sea animals and the problem that they often only allow identification of the animal or plant's genus, but not its exact species. What the fossils do show clearly is that apart from a few cataclysms over geological periods -- such as the one that eliminated the dinosaurs -- biodiversity has slowly increased. The new study next examined evidence from the evolutionary family trees -- phylogenies -- of numerous plant and animal species. Phylogenies, constructed by studying DNA, trace how groups of species have changed over time, adding new genetic lineages and losing unsuccessful ones. They provide rich details of how species have diversified over time. "The diversification rate is the speciation rate minus the extinction rate," said co-author Lucas Joppa, a scientist at Microsoft Research in Redmond, Wash. "The total number of species on earth has not been declining in recent geological history. It is either constant or increasing. Therefore, the average rate at which groups grew in their numbers of species must have been similar to or higher than the rate at which other groups lost species through extinction." The work compiled scores of studies of molecular phylogenies on how fast species diversified. For a third approach, de Vos noted that the exponential climb of species diversity should take a steeper upward turn in the current era because the newest species haven't gone extinct yet. "It's rather like your bank account on the day you get paid," he said. "It gets a burst of funds -- akin to new species -- that will quickly become extinct as you pay your bills."

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By comparing that rise of the number of species from the as-yet unchecked speciation rate with the historical trend (it was "log-linear") evident in the phylogenies, he could therefore create a predictive model of what the counteracting historical extinction rate must have been. The researchers honed their models by testing them with simulated data for which they knew an actual extinction rate. The final models yielded accurate results. They tested the models to see how they performed when certain key assumptions were wrong and on average the models remained correct (in the aggregate, if not always for every species group). All three data approaches together yielded a normal background extinction rate squarely in the order of 0.1 extinctions per million species per year. A human role There is little doubt among the scientists that humans are not merely witnesses to the current elevated extinction rate. This paper follows a recent one in Science, authored by Pimm, Joppa, and other colleagues, that tracks where species are threatened or confined to small ranges around the globe. In most cases, the main cause of extinctions is human population growth and per capita consumption, although the paper also notes how humans have been able to promote conservation. The new study, Pimm said, emphasizes that the current extinction rate is a more severe crisis than previously understood. "We've known for 20 years that current rates of species extinctions are exceptionally high," said Pimm, president of the conservation nonprofit organization SavingSpecies. "This new study comes up with a better estimate of the normal background rate -- how fast species would go extinct were it not for human actions. It's lower than we thought, meaning that the current extinction crisis is much worse by comparison."

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Researchers rethink 'natural' habitat for wildlife By Rob Jordan, Stanford University Science Daily APRIL 18, 2014 Protecting wildlife while feeding a world population predicted to reach 9 billion by 2050 will require a holistic approach to conservation that considers human-altered landscapes such as farmland, according to Stanford researchers. Wildlife and the natural habitat that supports it might be an increasingly scarce commodity in a world where at least three-quarters of the land surface is directly affected by humans and the rest is vulnerable to human-caused impacts such as climate change. But what if altered agricultural landscapes could play vital roles in nurturing wildlife populations while also feeding an ever-growing human population? A new study, published April 16 in the journal Nature and co-authored by three Stanford scientists, finds that a long-accepted theory used to estimate extinction rates, predict ecological risk and make conservation policy recommendations is overly pessimistic. The researchers point to an alternative framework that promises a more effective way of accounting for human-altered landscapes and assessing ecological risks. Current projections forecast that about half of Earth's plants and animals will go extinct over the next century because of human activities, mostly due to our agricultural methods. "The extinction under way threatens to weaken and even destroy key parts of Earth's life-support systems, upon which economic prosperity and all other aspects of human well-being depend," said co-author Gretchen Daily, the Bing Professor in Environmental Science at Stanford and senior fellow at the Stanford Woods Institute for the Environment But that grim future isn't a foregone conclusion. "Until the next asteroid slams into Earth, the future of all known life hinges on people, more than on any other force," Daily said. Nature is not an island Conservationists have long assumed that once natural landscapes are fractured by human development or agriculture, migration corridors for wildlife are broken, blocking access to food, shelter and breeding grounds. A scholarly theory was developed to estimate the number of species in such fractured landscapes, where patches of forest surrounded by farms resemble islands of natural habitat. The "equilibrium theory of island biogeography" is a pillar of biological research -- its elegant equation to estimate the number of species in a habitat has almost reached the status of a scientific law, according to Chase Mendenhall, a Stanford doctoral student in biology and the study's lead author. The theory drives the default strategy of conserving biodiversity by designating nature reserves. This strategy sees reserves as "islands in an inhospitable sea of human-modified habitats" and doesn't adequately account for biodiversity patterns in many human-dominated landscapes, according to the Stanford study. "This paper shows that farmland and forest remnants can be more valuable for biodiversity than previously assumed," said Daniel Karp, who earned his PhD in biology at Stanford in 2013 and is currently a NatureNet postdoctoral fellow at the University of California, Berkeley. "If we're valuing coffee fields and other human-made habitats at zero, we're doing a disservice to ourselves and wildlife," Mendenhall said. To test the island theory against a more holistic theory of agricultural or countryside biogeography, the researchers turned to bats acutely sensitive to deforestation. The study focused on bat populations within a mosaic of forest fragments and farmland in Costa Rica and on islands in a large lake in Panama. The researchers also did a meta-analysis of 29 studies of more than 700 bat species to bolster and generalize their findings globally. Island biogeographic theory accurately predicted bats' responses to forest loss on the Panamanian islands system, but didn't come close to accurately forecasting similar responses in the Costa Rican countryside landscape. For

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example, the island theory predicted that the Costa Rican coffee plantations would have inadequate habitat to sustain a single species of bat. In reality, plantations in the countryside typically supported 18 bat species, compared to the 23 to 28 supported by tropical forest fragments and nature reserves. "Conservation opportunities for tropical wildlife are tightly linked to adequate management of these human-modified habitats," said co-author Christoph Meyer, a researcher at the University of Lisbon's Center for Environmental Biology. Overall, as forest cover disappeared, the rate of species loss was "substantially and significantly higher" in the island ecosystem, and species abundances were "increasingly uneven" compared to the countryside ecosystem, the study found. The reason for the discrepancies, according to the study's authors, is that island biogeographic theory was originally based on actual islands surrounded by water, and does not account for factors such as a countryside landscape's ability to support more species and slow extinction rates compared to true island ecosystems. Especially in the tropics, island biogeographic theory's application is "distorting our understanding and conservation strategies in agriculture, the enterprise on which the future of biodiversity most critically hinges," the study's authors wrote. "Not only do more species persist across the 'sea of farmland' than expected by island biogeographic theory, novel yet native species actually thrive there," said co-author Elizabeth Hadly, the Paul S. and Billie Achilles Professor in Environmental Biology at Stanford and senior fellow at the Stanford Woods Institute for the Environment. "This indicates that human-altered landscapes can foster more biological diversity than we anticipated." A new approach The fate of much of the world's wildlife is playing out in human-altered landscapes that are increasingly threatened by chemical inputs such as herbicides and pesticides. Biodiversity is not the only loser. People are losing many of nature's benefits such as water purification provided by forests and wetlands and pest control provided by birds and bats. The study's findings point to the need for new approaches that integrate conservation and food production, to make agricultural lands more hospitable to wildlife by reducing chemical inputs, preserving fragments of forest and other natural habitats and rewarding farmers and ranchers for the benefits that result. "A theory of countryside biogeography is pivotal to conservation strategy in the agricultural ecosystems that comprise roughly half of the global land surface and are likely to increase even further in the future," the researchers wrote.

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Back From the Dead: Why De-Extinction May Save Humanity

By John Roach NBC News JULY 24, 2014

If current trends continue, elephants, giraffes, and zebras could go extinct in the not-too-distant future.

Rodents teeming with parasites that carry black plague would fill the void, suggests ongoing research in Africa. If so, the threat to human health could prompt the tantalizingly feasible solution of de-extinction -- that is, resurrecting the big animals and releasing them back into the wild.

De-extinction for conservation purposes is a "matter of when, not if," said Philip Seddon, a zoologist at the University of Otaga in New Zealand. "We need to think very hard about which are the good candidate species."

The need for serious consideration of the idea stems from the reality that the world is in the throes of an extinction crisis and demands a re-think of wildlife conservation, he and other scientists argue in a series of papers and essays published Thursday in the journal Science.

Rodolfo Dirzo at Stanford University, who is conducting the rodent research in Africa, is hesitant when it comes to resurrecting extinct species, preferring instead to focus on slowing human population growth and its impact on the environment with the development of a "view that the well-being of natural ecosystems including the animals actually represents the well-being of humans as well."

But the case could be made, he said, to bring back a recently-extinct species if its habitat is intact and the local communities are on board with the idea. Even then, though, many scientific and ethical questions remain to be explored, he and other scientists said.

"In most cases, (de-extinction) is very much a distraction from the big issues of conservation, which are more and more looking closer and closer to how does sustainable development happen, how do we live effectively on this planet without just completely removing the wealth of biology that we depend on," said Joshua Tewksbury, director of the conservation organization WWF's Luc Hoffman Institute in Geneva and co-author of an essay on the crisis.

'Defaunation' of Earth

Since the year 1500, at least 322 vertebrate species have gone extinct such as the dodo. Across vertebrates, population abundance has declined by 28 percent over the past four decades with many local populations now extinct. Globally, populations of invertebrates –- insects such as beetles, butterflies, and spiders -- have decreased by 45 percent over the past 40 years.

"So profound is this problem that we have applied the term 'defaunation' to describe it," Dirzo and colleagues write in their review paper on the crisis. "This recent pulse of animal loss … is not only a conspicuous consequence of human impacts on the planet but also a primary driver of global environmental change in its own right."

Among the consequences of this wave of extinction are losses of ecosystem services vital to the well-being of humans, such as crop pollination, agricultural pest control, seed dispersal, decomposition and cycling of nutrients, water filtration, and the supply of chemical compounds that may prove essential for novel, life-saving pharmaceuticals.

"There are ecological, economic, and ethical consequences of those losses -– and this important paper documents them in considerable detail," Stuart Pimm, a conservation ecologist at Duke University in Durham, N.C., said in an email. He was not involved in the Science series.

Dirzo's research in Kenya indicates that as large animals such as elephants, giraffes, and zebras decline, grasses and shrubs grow taller and thicker, obscuring rodents from the view of predators and allowing their populations to expand. "In the absence of the big animals, you tend to double the number of rats," he said. The rats carry parasites that harbor a range of diseases, including black plague.

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Moving species and de-extinction

Finding success in stemming extinction with traditional conservation measures such as protecting patches of wilderness and limiting hunting is "proving difficult," said Seddon, who is the lead author of a review paper that calls for an embrace of more intensive, and sometimes controversial, strategies such as translocation and even de-extinction.

At one end of what he calls the translocation spectrum is the movement of species from one place to another to augment an existing population with greater numbers or genetic diversity, for example.

Further along the spectrum are ideas such as reintroducing a species that has gone locally extinct, such as was done with wolves in the Northern Rockies. More controversial approaches include moving a species to a place it hasn't been before to avoid extinction from factors such as climate change or invasive species.

"The other end of that is when you say we want to move things not necessarily, or only, for that species but because we want to restore or increase the resilience of the whole ecosystem," Seddon said.

This last case, he explained, is known as ecological replacement. This has already been carried out, for example, on islands in the Indian Ocean where an exotic species of giant tortoise was released to restore the grazing and seed dispersal services that were lost when the local tortoise went extinct.

De-extinction, he said, could play a role within this translocation spectrum, especially as reintroduction to a native, intact habitat or as an ecological replacement.

But the concept is controversial. "There is a very real worry that if you feel that you can just bring anything back at any time you want you actually reduce the urgency of the issue," said WWF's Tewksbury. "And the issue isn't just around an individual species, but its value in a cultural context, its value in an ecosystem context, its value within an economic context."

According to Seddon, concerns about de-extinction warrant active and vigorous debate but "we've got to acknowledge it is on the horizon and figure out how to maximize the benefits for conservation."