Directions: Divide your students into group, assigning each group one of the SN Top 10 articles. Ask students to answer questions No. 1 and 2 before they read (5 minutes). After allowing 20 minutes for silent reading, have students answer questions No. 3 through 6 (20 minutes). You can ask each group to share the results with the class.

2018 Year in Review: Top 10

1. “Half a degree stole the climate spotlight
Readability score: 10.8

2. “Claim of first gene-edited babies sounded alarms
Readability score: 10.2

3. “Crime solvers embraced genetic genealogy
Readability score: 11.0

4. “Neutrino discovery ushered in a new era of astronomy
Readability score: 12.8

5. “Crater renewed debate over an ancient climate mystery
Readability score: 11.1

6. “We nudged closer to the Mosquito Terminator
Readability score: 11.8

7. “Researchers sent mixed messages about drinking
Readability score: 10.5

8. “A buried lake on Mars excited and baffled scientists
Readability score: 9.0

9. “Paralysis became less permanent with electricity
Readability score: 11.2

10. “Human smarts got a surprisingly early start
Readability score: 13.6

1. Read the headline of the article. What background information do you already know about the topic based on the headline?

2. Given the headline, what do you want or expect to learn when you read the article?

3. Summarize what you learned from the article in 100 words or less.

Possible student responses:

Story 1. “Half a degree stole the climate spotlight

A new report by the Intergovernmental Panel on Climate Change examined the predicted environmental impacts if the average global temperature rises by either 1.5 or 2.0 degrees Celsius above preindustrial levels by the year 2100. Though either scenario comes with dramatic consequences, holding to 1.5 degrees C would mean less sea level rise, fewer species lost to habitat degradation and fewer life-threatening heat, drought and precipitation extremes. The report notes that the planet’s average temperature has already increased by nearly 1 degree C and that rise is contributing to extinctions, lower crop yields and more frequent wildfires.

Story 2. Claim of first gene-edited babies sounded alarms

A Chinese researcher, Jiankui He, claims to have produced the first gene-edited babies and says at least one more baby is on the way. He said he used the gene-editing tool CRISPR/Cas9 to disable the CCR5 gene in fertilized eggs, with the goal of making the babies born from those eggs resistant to HIV infection. Other researchers are not convinced that the gene editing was successful or that it didn’t damage other genes. The researchers note that disabling CCR5 might increase susceptibility to serious complications from infections like West Nile.

Story 3.Crime solvers embraced genetic genealogy

In 2018, law enforcement arrested at least 18 suspects with the help of genetic genealogy searches. Investigators compared DNA profiles from crime scenes with DNA profiles from more than a million people who have voluntarily put their DNA data online to search for relatives. Even though the suspects did not upload their DNA profiles, relatives had, enabling investigators to identify the suspects by re-creating their family trees. This new type of DNA-based detective work has raised questions about genetic privacy and police procedures.

Story 4.Neutrino discovery ushered in a new era of astronomy

The IceCube neutrino observatory in Antarctica detected a high-energy neutrino from one region of space. Soon after, astronomers spotted a flare from a blazar about 4 billion light-years away in that same region. Old data yielded evidence of even more neutrinos from near the blazar’s location in the sky, which helped convince some researchers that the blazar birthed neutrinos. With upgraded technology and more detections, neutrinos might be used to probe blazars and other potential sources, such as neutron star collisions.

Story 5.Crater renewed debate over an ancient climate mystery

NASA scientists have identified what appears to be a 31-kilometer-wide crater beneath Greenland’s Hiawatha Glacier. Based on elements in glacial outwash, the discoverers think that an iron meteorite made the crater, which likely formed between 2.6 million and 11,700 years ago. Some scientists wonder if the impact could be responsible for an ancient cold snap that began 12,800 years ago and has been blamed for the extinction of the mammoths and the disappearance of a group of people known as the Clovis.

Story 6. We nudged closer to the Mosquito Terminator

Scientists at Imperial College London used a gene drive to exterminate two small lab populations of malaria-causing Anopheles gambiae mosquitoes. In lab tests, mosquitoes that were given a gene that made female mosquitoes unable to reproduce passed that gene to all of their offspring. The populations went extinct within a few generations. If that technique works in the wild, it could eliminate mosquitoes that carry certain diseases, but the tool is a long way from practical use and ethical concerns abound.

Story 7.Researchers sent mixed messages about drinking

In 2018, two studies contradicted evidence that an occasional drink might have health benefits. Both studies were meta-analyses, combining data from numerous observational studies that tracked what large numbers of people drank over time and compared rates of disease or death in those populations. In one study, people who had more than about seven drinks per week had a lower life expectancy and a higher risk of stroke, heart failure and other problems compared with light drinkers. The second study claimed that anything more than abstinence, or no drinks at all, is risky. Some researchers took issue with broad conclusions and noted problems with the design of meta-analyses.

Story 8. A buried lake on Mars excited and baffled scientists

The European Space Agency’s Mars Express orbiter spotted what appears to be a lake of liquid water beneath ice near the Red Planet’s south pole. Scientists are puzzled that NASA’s Mars Reconnaissance Orbiter hasn’t detected the lake, and they wonder how the water could stay liquid under 1.5 kilometers of ice when the temperature at that depth should be about –68° Celsius. One scientist speculates that the polar ice cap could be porous enough to keep the liquid water from freezing and to interfere with measurements from the NASA orbiter. If the lake does exist, any life that arose on early Mars might still hang on there.

Story 9.Paralysis became less permanent with electricity

Six paralyzed people were able to walk or take steps years after their injuries thanks to intensive rehabilitation and electric stimulation of their spinal cords, three small studies showed. Scientists are still trying to figure out why the stimulation works. It could be that the electrical stimulation acts like a hearing aid to boost signals between the spinal cord and the brain. It’s also possible that the electric stimulation helps rebuild weakened neural connections.

Story 10. Human smarts got a surprisingly early start

A number of archaeological finds have pushed the roots of innovative behavior closer to the origin of the human genus, Homo, showing just how clever and adaptable our ancient relatives were. Among the findings: Hominids in East Africa created and traded new types of stone tools in the face of frequent climate swings 320,000 years ago. Humans in South Africa were making art 73,000 years ago, and a painted figure in Southeast Asia dates to 40,000 years ago. Neandertals left rock art in Spanish caves 64,800 years ago. And humanlike populations may have reached central China by 2.1 million years ago.

4. What questions do you still have after reading the article? What new questions do you have?

5. What research project might you propose to address one of the questions that you still have?

6. Log in to your Science News in High Schools account and use the Search page to find an older article on the same topic. What is the article title and when was it published? Name one fact that was previously known (from the old article) and one new or changed fact that the new article provides?

Possible student responses:

New article: Claim of first gene-edited babies sounded alarms

Old article: “Most Americans think it’s OK to tweak a baby’s genes to prevent disease,” published July 26, 2018

Old fact: 72 percent of Americans surveyed favored changing an unborn baby’s genetic makeup to treat a disease present at birth.

New/changed fact: There are widespread concerns about the health, ethical and social implications of newly born gene-edited babies.

New article: “Crime solvers embraced genetic genealogy

Old article: “What genetic tests from 23andMe, Veritas and Genos really told me about my health,” published May 22, 2018

Old fact: Personal genetic testing can provide interesting information about your family history but generally limited information about your health.

New/changed fact: Personal genetic testing is helping law enforcement officials track down criminals.

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