Passage Excerpt from “It’s Time to Stop Thinking That All Non-Native Species Are Evil”
Excerpt from “It’s Time to Stop Thinking That All Non-Native Species Are Evil”
by Emma Marris
The author of this opinion article attended a symposium, or conference, in Missoula, Montana, at which biologists and other scientists discussed species of plants and animals that are not native to the areas in which they live.
Invasive species are scary. It was ecologist Charles Elton, back in the 1950s, who introduced the militaristic “invasion” metaphor to describe exotic plants and animals—but there’s no question some can be extremely destructive.
The brown tree snake has eaten a dozen kinds of forest birds in Guam to extinction; zebra mussels clog pipes around the Great Lakes; the common house cat turns out to be, in Australia, a mercilessly effective killer of cute, fluffy marsupials like the bilby and the numbat.
As scientists have sounded the alarm about these pests, the public has gotten the message. Citizen groups rip out non-native plants. Native gardens have become increasingly popular, both as ways to celebrate the unique flora of each region and as tiny hot spots of diversity. Native trees provide food for native bugs, which feed native birds. Food chains developed over thousands of years of co-evolution unfold in our backyards. . . .
So we’ve learned, scientists and laypeople alike, that native species are good and non-natives are bad.
Julian Olden, a biologist at the University of Washington, Seattle, who co-organized the symposium, recently polled nearly 2,000 ecologists. Among his findings: a substantial number of them said they would immediately eradicate a hypothetical non-native forest plant, even if it were shown to have no effect on the forest. Olden calls this the “guilty even when proven innocent” approach.
That kind of approach is not very useful on a rapidly changing planet.
Exotics Are Everywhere
Climate change is making it harder even to decide who the invaders are.
How, scientists at the symposium wondered, do you define “native” on a warming planet, when plants and animals are already moving toward the poles or up mountainsides in search of climate conditions they can tolerate? Should we consider them “invasive” in their new homes? Regardless of what we label them, conservationists will be reluctant to remove them from their new environs—to do so would stymie1 their chances of adapting to the warmer future we’re creating.
And then there are the non-natives that we actually like. Most domestic crops are exotic in most of the places they’re grown, but there are even wild exotics that “do good,” forming useful relationships with native species.
Edwin Grosholz of the University of California, Davis, told the recent symposium about one such relationship. On beaches in his state, non-native spartina grass has become important habitat for the endangered California clapper rail, a plump shorebird with a downward curving bill more at home on land than in the air. A project to rip out and poison the spartina—which grows in dense swaths that exclude many other shorebirds—saw clapper rail numbers go tumbling downward.
There are other examples like that. The endangered southwestern willow flycatcher nests in “invasive” tamarisk shrubs. Many native (and beautiful) Hawaiian flowers are now pollinated by the Japanese white-eye bird—because the native pollinators have been driven extinct by other non-native species.
Should we impose further risk on already endangered natives by severing these relationships? Or should we admire the resilience of nature and let such “well-behaved” exotics stay? . . .
Leave them alone, more and more conservationists are arguing, and stop focusing obsessively on categorizing species as native or non-native. Mark Davis, an ecologist at Macalester College in St. Paul, Minnesota, once considered himself an “invasion biologist”—but not anymore. “I am actively trying to get the field to retire the invader narrative,” he said in Missoula.
A Good Thing, Not the Only Thing
After all, nativeness is just one environmental value, and arguably not as important as preventing extinctions and preserving biodiversity. In some cases we can best serve biodiversity by leaving the non-natives alone or even—brace yourself, now—introducing them on purpose.
This is the thinking behind, for example, installing the Aldabra tortoise on the islands of Mauritius. The islands lost their own large tortoises, and the fruiting plants that formerly had their seeds moved around by these fruit-loving reptiles have been on the decline. A tortoise that’s related to the island’s large tortoises—a non-native from the Seychelles in the Indian Ocean that was intentionally introduced in 2004—is now handling some of that work.
Most of the time, for the time being, conserving species still means focusing on supporting them in their historical habitats, planting natives and removing non-natives. We can and should do that in places where it is feasible and important to us.
From “It’s Time to Stop Thinking That All Non-Native Species Are Evil” by Emma Marris from NATIONAL GEOGRAPHIC MAGAZINE, July 24, 2014. Copyright © 2014 by National Geographic Society.
1stymie: hinder or interfere with
Question
Determine whether each sentence from the excerpt presents a claim or presents evidence to support a claim.
Select all the correct answers.
Choose one answer in each row, then check. The DOE has not published how answers with several parts are scored; this site counts one right only when every part is right.
| Presents a Claim | Presents Evidence | |
|---|---|---|
| “That kind of approach is not very useful on a rapidly changing planet.” (paragraph 6) | ||
| “A project to rip out and poison the spartina—which grows in dense swaths that exclude many other shorebirds—saw clapper rail numbers go tumbling downward.” (paragraph 10) | ||
| “In some cases we can best serve biodiversity by leaving the non-natives alone or even—brace yourself, now—introducing them on purpose.” (paragraph 14) | ||
| “A tortoise that’s related to the island’s large tortoises—a non-native from the Seychelles in the Indian Ocean that was intentionally introduced in 2004—is now handling some of that work.” (paragraph 15) |
Show the answer
Correct answer: “That kind of approach is not very useful on a rapidly changing planet.” (paragraph 6): Presents a Claim; “A project to rip out and poison the spartina—which grows in dense swaths that exclude many other shorebirds—saw clapper rail numbers go tumbling downward.” (paragraph 10): Presents Evidence; “In some cases we can best serve biodiversity by leaving the non-natives alone or even—brace yourself, now—introducing them on purpose.” (paragraph 14): Presents a Claim; “A tortoise that’s related to the island’s large tortoises—a non-native from the Seychelles in the Indian Ocean that was intentionally introduced in 2004—is now handling some of that work.” (paragraph 15): Presents Evidence
The question asks which quotations from the excerpt present a claim and which present evidence in support of a claim. (A claim is a statement made as part of an argument that can be supported or proved with evidence. Supporting evidence can include facts, figures, details, quotations, or other sources of data and information that can be evaluated by others.)
Row 1: Presents a claim [“That kind of approach is not very useful on a rapidly changing planet.” (paragraph 6)]. The phrase “is not very useful” indicates that the sentence expresses a claim—an arguable statement, or in this case an opinion, for which the author must provide proof.
Row 2: Presents evidence [“A project to rip out and poison the spartina—which grows in dense swaths that exclude many other shorebirds—saw clapper rail numbers go tumbling downward.” (paragraph 10)]. Despite its figurative language (“tumbling downward”), this sentence does not present a claim that must be supported by evidence. Instead, the sentence provides factual information—that numbers of clapper rail birds decreased when spartina grass was removed—that is evidence for another claim, that non-native plants can be welcome sometimes.
Row 3: Presents a claim [“In some cases we can best serve biodiversity by leaving the non-natives alone or even—brace yourself, now—introducing them on purpose.” (paragraph 14)]. The wording “we can best serve” signals that this sentence presents a claim—a statement being made as part of an argument that needs proof in order to be accepted—regarding the best way to achieve biodiversity.
Row 4: Presents evidence [“A tortoise that’s related to the island’s large tortoises—a non-native from the Seychelles in the Indian Ocean that was intentionally introduced in 2004—is now handling some of that work.” (paragraph 15)]. Although this sentence does not provide statistics, quotations, or other obvious markers that signal evidence, it does provide a factual example—non-native tortoises are now moving the seeds of fruiting plants in a way that preserves the diversity of plant life on the islands of Mauritius—that is used to support the author’s claim that non-native species can help preserve diversity.
Question analysis
This table-grid question on the opinion article about non-native species gives four sentences, from paragraphs 6, 10, 14 and 15, and asks whether each presents a claim or presents evidence to support a claim. Students make four separate decisions, and credit comes only when every row is right, so each sentence must be judged by the job it does in the author’s argument.
- Grade level
- Grade 7 reading and task
- Compared with grade 7
- At grade 7 Telling a claim from the evidence for it is core grade 7 argument work. The four sentences come labeled with their paragraphs, but they are long and broken by dashes and asides, and all four must be sorted correctly, a typical demand overall.
- Estimated difficulty
- Moderate: several steps, or a close reading with one strong distractor.
- Thinking it demands
- Depth of knowledge 2, skills and concepts · mainly analyze
- What makes it hard
- Much to keep track of moderate
- How, not what minor
- Complex sentences minor
- Figurative or literary language minor
- Evidence
- Answered from several paragraphs or stanzas
- Reading level
- Passage: about grade 11, 815 words; question and choices: about grade 8, 22 words.
- Students, last 30 days
- Not enough answers yet to show (it takes 10).
Why it is hard, traps and wrong answers (shows the answer)
Why it is hard
The two claims carry the author’s judgment in a few words, “not very useful” and “we can best serve,” while the two evidence rows report what happened. Students go wrong when they sort by surface: dramatic wording makes the spartina report sound like opinion, and the tortoise sentence, with no number or quotation, can pass for the author’s assertion. Asking whether a sentence judges or reports settles each row, but all four must be right for credit.
Much to keep track of moderate Working it out
Sentences from paragraphs 6, 10, 14 and 15 are judged one at a time, and the question is scored right only when all four rows are, so one doubtful row costs the point. (Sweller, 1988; Carpenter, Just & Shell, 1990)
How, not what minor Working it out
Each row asks what a sentence does in the argument, not what it is about: rows 3 and 4 both concern bringing in non-natives on purpose, but one argues for it and one reports it. (Anderson & Krathwohl, 2001)
Complex sentences minor Understanding the question
In the two evidence rows, 17 and 22 words separate the subject from its verb, “A project … saw” and “A tortoise … is now handling,” most of them inside dashes. (Abedi & Lord, 2001; Freedle & Kostin, 1993; Messick, 1989)
Figurative or literary language minor Understanding the question
Row 2 reports a result in vivid words, a project to “rip out and poison” the grass and clapper rail numbers that “go tumbling downward,” so a report can sound like an opinion. (Graesser, Singer & Trabasso, 1994; Kintsch, 1998)
Strategy: For each sentence, ask whether it states a judgment the author must argue for or reports something that happened or was found, and sort it by that test alone.
Traps
- Wrong purpose or structure: Names a purpose, structure or effect that the part does not serve, or describes what a part says when the question asks what it does.
- Wrong tone or attitude: Misjudges the tone, attitude or point of view, such as reading admiration as criticism, or taking a character's or subject's feelings for the author's.
The wrong answers, classified
1:B Wrong purpose or structure (Anderson & Krathwohl, 2001)
Takes “a rapidly changing planet” as plain fact, the climate change the next section describes, and misses that “not very useful” is the author’s own verdict on the approach Olden describes.
2:A Wrong tone or attitude (Graesser, Singer & Trabasso, 1994)
Hears opinion in the vivid “rip out and poison” and “go tumbling downward,” though the sentence reports what happened to clapper rail numbers once a project removed the spartina.
3:B Wrong purpose or structure (Anderson & Krathwohl, 2001)
Sees that the sentence backs the case for leaving non-natives alone and so calls it support, missing that “we can best serve” is itself a claim, which the tortoise example then backs.
4:A Wrong purpose or structure (Anderson & Krathwohl, 2001)
Expects evidence to come as numbers, studies or quotations, so takes the plain report that a tortoise brought in during 2004 “is now handling some of that work” as an assertion.
Working it out, step by step
Figure out what the question asks
Decide the job each of the four sentences does in the argument. A claim is a statement the author wants you to accept, such as an opinion or a judgment. People could disagree with it, so it needs support. Evidence is a fact, an example or an event that backs up a claim. Ask: does the sentence judge, or does it report what happened?
Sort the sentence from paragraph 6
Row 1 says “That kind of approach is not very useful on a rapidly changing planet.” The approach is the one in paragraph 5. There, many ecologists said they would wipe out a non-native plant even if it had no effect on the forest. The words “not very useful” are the author’s judgment. Someone could disagree, so the article has to argue for it. This sentence presents a claim.
Watch out: “A rapidly changing planet” sounds like a fact. But the point of the sentence is the judgment about the approach.
Sort the sentence from paragraph 10
Row 2 is long, so set aside the part between the dashes. What is left says “A project to rip out and poison the spartina” saw clapper rail numbers fall. Spartina is a grass that is not native to California. The clapper rail is an endangered shorebird that lives in it. So the sentence reports what happened: the grass was removed, and the birds declined. It backs the claim in paragraph 9 that some non-natives “do good.” This row presents evidence.
Watch out: Vivid words like “go tumbling downward” can sound like an opinion. But they only mean the numbers fell fast. Strong wording does not turn a report into a claim.
Sort the sentence from paragraph 14
Row 3 says “In some cases we can best serve biodiversity by leaving the non-natives alone or even—brace yourself, now—introducing them on purpose.” Biodiversity is the variety of living things in a place. The words “we can best serve” show the author’s judgment about what is best. “Brace yourself” shows she expects you to be surprised. A surprising idea needs proof. This sentence presents a claim.
Sort the sentence from paragraph 15
Row 4 also has a long part between dashes. Without it, the sentence says “A tortoise that’s related to the island’s large tortoises” is “now handling some of that work.” The sentence before explains the work. The islands lost their own large tortoises, which used to spread the seeds of fruiting plants. Now a non-native tortoise, brought in on purpose in 2004, does part of that job. It is a real example. It backs row 3’s claim. This row presents evidence.
Watch out: Evidence does not need numbers or quotations. An example of what happened counts.
Fill in the table
- Row 1 (paragraph 6): Presents a Claim
- Row 2 (paragraph 10): Presents Evidence
- Row 3 (paragraph 14): Presents a Claim
- Row 4 (paragraph 15): Presents Evidence
On the test and on this site, click one circle in each row. All four rows must be right to get the point.
Why this answer and not the closest wrong one
Row 2 is the hardest. “Rip out and poison” and “tumbling downward” sound strong, like an opinion. But the sentence reports a project and its result: the bird numbers fell. Nobody judges what is best. So it is evidence for the claim that some non-natives “do good.”
More questions like this
The original DOE question
The passage “Excerpt from “It’s Time to Stop Thinking That All Non-Native Species Are Evil”” as printed (pages 68–70)
