Passage Excerpt from “The Past and the Future of the Earth’s Oldest Trees”
Excerpt from “The Past and the Future of the Earth’s Oldest Trees”
by Alex Ross
About forty-five hundred years ago, not long after the completion of the Great Pyramid at Giza, a seed of Pinus longaeva, the Great Basin bristlecone pine, landed on a steep slope in what are now known as the White Mountains, in eastern California. The seed may have travelled there on a gust of wind, its flight aided by a winglike attachment to the nut. Or it could have been planted by a bird known as the Clark’s nutcracker, which likes to hide pine seeds in caches; nutcrackers have phenomenal spatial1 memory and can recall thousands of such caches. This seed, however, lay undisturbed. On a moist day in fall, or in the wake of melting snows in spring, a seedling appeared above ground—a stubby one-inch stem with a tuft of bright-green shoots.
Most seedlings die within a year; the mortality rate is more than ninety-nine percent. The survivors are sometimes seen growing in the shadow of a fallen tree. The landscape of the Ancient Bristlecone Pine Forest, as this area of the White Mountains is called, is littered with fragments of dead trees—trunks, limbs, roots, and smaller chunks. Pinus longaeva grows exclusively in subalpine regions of the Great Basin, which stretches from the eastern slopes of the Sierra Nevada to the Wasatch Range, in Utah. Conditions are generally too arid for the dead wood to rot; instead, it erodes, sanded down like rock. The remnants may harbor nutrients and fungi that help new trees grow. Bristlecones rise from the bones of their ancestors—a city within a cemetery.
Coast redwoods and giant sequoias, California’s gargantuan world-record-holding trees, can grow fifty feet or more in their first twenty years. Bristlecones rise agonizingly slowly. After four or five years, the seedling on the steep slope would have been just a few inches higher, sprouting needles in place of the embryonic shoots. The needles are a deep green, tough, resinous, and closely bunched in groups of five. On a mature tree, they live for fifty years or more. Decades may have passed before the tree was human height, and decades more before it resembled a conventional pine. Bristlecone saplings grow straight up, with relatively sparse foliage, looking like undernourished Christmas trees. After a few hundred years—by which time the Old Kingdom of Egypt had fallen—it was probably forty or fifty feet in height.
Many tree species live for hundreds of years. A smaller but not inconsiderable number, including the sequoias and certain yews, oaks, cypresses, and junipers, survive for thousands. Once a bristlecone has established itself in the unforgiving conditions of the White Mountains, it can last almost indefinitely. The trees tend to grow some distance from one another, so fires almost never destroy an entire stand. Because only a few other plant species can handle the dry, cold climate, the bristlecones face little competition. Unlike most plants, they tolerate dolomite soil, which is composed of a chalky type of limestone that is heavily alkaline and low in nutrients. As for insect threats, bristlecone wood is so dense that mountain-pine beetles and other pests can rarely burrow their way into it.
Empires rose and fell; wars raged; . . . and the tree from 2500 B.C. continued its implacable slow-motion existence, adding about two-hundredths of an inch to the diameter of its trunk each year. Minute changes in the tree-ring record make bristlecones an exceptionally useful source of data about changing conditions on Earth. When rains are heavier than normal, the rings widen. When volcanic eruptions cause global cooling, frost rings make the anomaly2 visible. . . .
As the millennia go by, bristlecones become contorted and wraithlike.3 The main stem, or leader, dies back. Entire branches, even the trunk itself, become fossils. At first glance, the tree may look dead. Such is the case of the forty-five-hundred-year-old tree that clings to life near the tourist path that now runs through the Ancient Bristlecone Pine Forest. Spears of dead wood jut into the air. The trunk is a marbled hulk stripped of bark, like driftwood thrown from a vanished ocean. A ribbon of live bark runs up one side, funneling water and nutrients to clumps of green needles high above. All told, the tree is an unprepossessing specimen; most people march past it without giving it a second glance. . . .
. . . No two super-elderly trees look alike, to the point where they have acquired the characteristics of individuals. Trees are prone to anthropomorphism; we project our dreams and our anxieties onto them. Bristlecones have been called elders, sentinels, sages. The possibility that climate change will cause their extinction has inspired a spate4 of alarmed news stories, although tree scientists tend to discount the idea that the bristlecones are in immediate danger. They have survived any number of catastrophes in the past; they may survive humanity.
From “The Past and the Future of the Earth’s Oldest Trees” by Alex Ross from THE NEW YORKER, January 20, 2020. Copyright © 2020 by Condé Nast. All rights reserved.
1spatial: relating to physical space
2anomaly: oddity
3wraithlike: ghostly
4spate: sudden abundance
Question
The details in paragraph 7 convey a central idea of the excerpt by suggesting that
- Athe success of the bristlecone pine lies in its ability to resist climate change.
- Bthe uncommon appearance of the bristlecone pine is related to its ability to survive.
- Cthe attachment that humans have to the bristlecone pine is understandable.
- Dthe longevity of the bristlecone pine continues to encourage experts.
Show the answer
Correct answer: D
The question asks which central idea of the excerpt is supported by the details in paragraph 7.
A. Incorrect. While paragraph 7 mentions the pines’ ability to survive climate change, the central idea is about the trees’ longevity. Surviving climate change is a part of the pines’ longevity, but just surviving climate change does not fully encompass the central idea of the excerpt.
B. Incorrect. Although the paragraph mentions that the “super-elderly trees” are each unique in appearance, their appearance does not directly connect to their ability to survive. The details in paragraph 7 emphasize the durability and longevity of the trees.
C. Incorrect. While the beginning of paragraph 7 expresses the idea that each bristlecone pine appears to be a unique individual and supports the idea that humans relate to the pines, the paragraph expresses a stronger central idea in the last two sentences about the pines’ survival.
D. CORRECT. The longevity of bristlecone pines is a central idea of the excerpt. Experts are encouraged that bristlecone pines have survived many catastrophes, and the details in the second half of paragraph 7 draw direct attention to the trees’ longevity.
Question analysis
Students explain how the details in paragraph 7, the closing paragraph of Alex Ross’s excerpt on bristlecone pines, convey a central idea of the whole piece. The paragraph moves from people seeing old trees as individuals to alarmed news stories and the views of tree scientists, so students must decide which thread ties to the excerpt’s main idea.
- Grade level
- Grade 8 reading and task
- Compared with grade 7
- Above grade 7 Grade 7 central idea questions often ask what a passage is mostly about. Here students must connect one closing paragraph that touches several topics to an idea of the whole excerpt, reading its details for what they imply as well as what they say.
- Estimated difficulty
- Hard: combines ideas, needs a plan, and has more than one tempting wrong answer.
- Thinking it demands
- Depth of knowledge 3, strategic thinking · mainly understand
- What makes it hard
- Reading between the lines major
- The right answer is reworded moderate
- Evidence in several places minor
- Evidence
- Answered from the whole text
- Reading level
- Passage: about grade 8, 851 words; question and choices: about grade 10, 63 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
Paragraph 7 moves through several topics, trees that look like individuals, people projecting feelings onto them, alarmed news and calm scientists, and only its last two sentences connect to the excerpt’s main idea. The strongest lure states a true point about human attachment that the paragraph does make, while the key has to be inferred from the scientists’ calm and the trees’ record of survival. Naming the central idea first, the trees’ extraordinary age, shows which thread of the paragraph serves it.
Reading between the lines major Working it out
Nothing in paragraph 7 says experts are encouraged; it has to be read from “tree scientists tend to discount the idea that the bristlecones are in immediate danger,” set against the “alarmed news stories.” (Graesser, Singer & Trabasso, 1994; Kintsch, 1998)
The right answer is reworded moderate Choosing the answer
The key speaks of “longevity” and of experts being encouraged, words the paragraph never uses, while two wrong choices repeat its “climate change” and “survive” and so look better anchored. (Freedle & Kostin, 1993; Kirsch & Mosenthal, 1990)
Evidence in several places minor Working it out
Recognizing longevity as a central idea draws on the whole excerpt: the tree from the time of the Great Pyramid in paragraph 1, its endurance in paragraph 4 and its ring record in paragraph 5. (Kirsch & Mosenthal, 1990; Gorin & Embretson, 2006)
Strategy: Name the central idea of the whole excerpt first, then reread paragraph 7 and find the sentences that connect to it.
Traps
- True but not the answer: A choice says something accurate about the text that does not answer this question.
- Twists what the text says: Uses the text's topic and ideas but changes what it says: who did it, how much, when, or why.
- Reads too much in: A reasonable-sounding conclusion that goes further than the text allows.
The wrong answers, classified
A Twists what the text says (King et al., 2004)
Joins the paragraph’s mention of climate change to the trees’ survival and makes resisting it the secret of their success, but the paragraph only reports fears and gives no such cause.
B Reads too much in (Graesser, Singer & Trabasso, 1994)
Links the remark that no two old trees look alike to their survival, a connection paragraph 7 never draws; the detail shows only that they seem like individuals.
C True but not the answer (King et al., 2004; Embretson & Wetzel, 1987)
Relies on the paragraph’s real remarks about people calling the trees elders, sentinels and sages, but that human attachment is a side point, not a central idea of the excerpt.
Working it out, step by step
Figure out what the question asks
This asks how paragraph 7 connects to a central idea, a main point of the whole excerpt. So first name that idea. Then find which details in paragraph 7 point to it.
Name the excerpt’s central idea
The excerpt follows a tree that has lived about 4,500 years. Paragraph 1 starts its story near the time of the Great Pyramid. A settled bristlecone “can last almost indefinitely” (paragraph 4). Paragraph 5 shows a tree living on while empires “rose and fell.” So a central idea is the bristlecone’s amazing longevity, or long life.
Find the matching details in paragraph 7
Paragraph 7 first says people treat the old trees almost like persons. Then it turns to climate change. News stories sound alarmed, “although tree scientists tend to discount the idea that the bristlecones are in immediate danger.” To discount an idea is to doubt it. The last sentence gives the reason: “They have survived any number of catastrophes in the past; they may survive humanity.”
Explain what the details suggest
A catastrophe is a terrible disaster. The trees have lived through so many disasters that scientists are not very worried. In other words, the trees’ long record of survival gives the experts hope. That ties paragraph 7 to the central idea of longevity.
Check each choice
- A does not fit. Climate change comes up only as a fear in the news. The paragraph never says the trees succeed by resisting it.
- B does not fit. Paragraph 7 says no two old trees look alike, but it never links their looks to their survival.
- C does not fit. People do call the trees “elders, sentinels, sages,” but that feeling is a side point, not a central idea.
- D fits. Experts take comfort from how long the trees have survived.
Choose the answer
Paragraph 7 ends on the trees’ long survival and the experts’ calm about their future. So the answer is D.
Why this answer and not the closest wrong one
C is the strongest trap, because paragraph 7 really does say people feel close to the trees. But the question asks for a central idea of the whole excerpt. Long life runs through every paragraph, and the last two sentences of paragraph 7 tie into it. That is why D fits better.
More questions like this
The original DOE question
The passage “Excerpt from “The Past and the Future of the Earth’s Oldest Trees”” as printed (pages 193–194)
