In the summer of 1960, doctors extracted “crimson sludge” from 6-year-old Barbara Lowry’s bones and gave it to her twin.

That surgery, one of the first successful bone marrow transplants, belied the difficulty of the procedure. In the early years of transplantation, scores of patients died as doctors struggled to figure out how to use one person’s cells to treat another. “Cell therapy for blood diseases had a terrifying birth,” Siddhartha Mukherjee writes in his new book, The Song of the Cell.

The transplant story is one of many Mukherjee uses to put human faces and experiences at the heart of medical progress. But what radiates off the pages is the author himself. An oncologist, researcher and Pulitzer Prize–winning author, Mukherjee’s curiosity and wisdom add pep to what, in less dexterous hands, might be dry material. He finds wonder in every facet of cell biology, inspiration in the people working in this field and “spine-tingling awe” in their discoveries.
It’s no surprise that Mukherjee is so seduced by science. This is a man who built a microscope from scratch during the pandemic and has spent years probing biology and its history with luminaries in the field. The Song of the Cell lets readers eavesdrop on these conversations, which can be intimate and enlightening.

On a car ride across the Netherlands, Mukherjee chats with geneticist Paul Nurse, who tells him about the cell division work that ultimately netted Nurse a Nobel Prize (SN: 3/27/21, p. 28). On a walk at Rockefeller University in New York

City, Mukherjee discusses his depression with another Nobel Prize–winning researcher, neuroscientist Paul Greengard. Mukherjee’s vivid imagery lends heft to his feelings. He tells Greengard about experiencing a “soupy fog of grief” after his father’s death and describes “drowning in a tide of sadness.”

In these memories, which Mukherjee uses to segue into the science of depression, and elsewhere in the book, hints of poetry shimmer among the prose. A cell observed under a microscope is “refulgent, glimmering, alive.” A white blood cell’s slow creep is like the “ectoplasmic movement of an alien.” Mukherjee weaves his experiences into the story of cell biology, guiding readers through the lives and discoveries of key figures in the field. We meet the “father of microbiology,” Antonie van Leeuwenhoek, a 17th century cloth merchant who ground globules of Venetian glass into microscope lenses and spied a “marvelous cosmos of a living world” within a raindrop. Mukherjee also teleports us to the present to introduce He Jiankui, the disgraced biophysicist behind the world’s first gene-edited babies (SN: 12/22/18 & 1/5/19, p. 20). Along the way, we also meet Frances Kelsey, the Food and Drug Administration medical officer who refused to approve thalidomide, a drug now known to cause birth defects, for use in the United States, and Lynn Margulis, the evolutionary biologist who argued that mitochondria and other organelles were once free-living bacteria (SN: 8/8/15, p. 22).

Mukherjee traverses a vast landscape of cell biology, and he’s not afraid to pull over and go exploring in the weeds. He describes in detail the flux of ions in nerve cells and introduces a considerable cast of immune system characters. For an even deeper dive, readers can check the footnotes; they are abundant.

What stands out most, though, are Mukherjee’s stories about people: scientists, doctors, patients and himself. As a researcher and a physician, he steps deftly between the scientific and clinical worlds, and, like the microscope he assembled, offers a glimpse into a universe we might not otherwise see.

Mountain lions have no interest in people, or the built-up areas we enjoy. But after a 2018 wildfire in California, local lions took more risks, crossing roads more often and moving around more in the daytime, scientists report October 20 in Current Biology. It’s another way the effects of human development could be putting pressure on vulnerable wildlife — in this case, potentially pushing them toward our bumpers.

The Woolsey Fire began near Los Angeles on November 8, 2018, and burned more than 36,000 hectares in the Santa Monica Mountains. Nearly 300,000 people evacuated, and three people died. Animals fled the fire too, including the local mountain lions (Puma concolor). The fire was a tragedy, but also a scientific opportunity, says Rachel Blakey, a global change biologist at UCLA. Many of the lions wore tracking collars, allowing scientists to study how the fire changed their behavior.
Of the 11 collared cougars in the area at the time, nine made it to safety during the fire itself. “They have really large home ranges, so it’s nothing to them to be able to cover many kilometers in a day,” Blakey says.

No matter how much they moved, the mountain lions avoided people. One collared cat, P-64, initially fled the fire — until he got close to a developed area. Given the choice between fire and people, the lion retreated back into the burning area. “That’s where his movements stopped,” Blakey says. The park service later found P-64’s remains. He’d burned his paws, and it’s possible that he was unable to hunt and starved to death.

Using data from the nine lions that survived the fire and others collared after, the scientists showed that the cats generally avoided the severely burned areas of their territories. With vegetation gone, the cats had little cover for stalking and ambushing prey.

Instead, the cougars stuck to unburned areas, and continued to avoid people. But they took more risks around human infrastructure, increasing their road crossings from an average of about three times per month to five.
These weren’t all two-lane country highways. The first collared lion to successfully cross Interstate 405, which has 10 lanes in places, did it after the Woolsey Fire. And the big cats crossed U.S. Route 101 once every four months, whereas before the fire, they’d crossed only once every two years. Their territories also overlapped more often, increasing the potential for deadly encounters between the solitary cats. And the generally nocturnal animals increased activity during daytime hours from 10 percent to 16 percent of their active time — boosting a lion’s chances of potentially bump into a human.

Road crossing is what Blakey calls a “risk mismatch.” Lions in areas with lots of people appear to weigh the risk of encountering humans as more dangerous. But “running across a freeway is a lot more likely to be fatal,” she says. That risk, combined with the risk of running into other cats, can be deadly. One young, collared male ended up dead on a freeway in the months after the fire. He was fleeing a fight with an older, uncollared male.

Intense burns like the Woolsey Fire highlight the resilience of mountain lions, says Winston Vickers, a wildlife research veterinarian at the University of California, Davis who was not involved in the study. “They have amazing mobility, they mostly can get away from the immediate fire, they mostly survive,” he notes. The changes in risk-taking, he says, could reflect how confined the population is, hemmed into the mountains by human development.

Wildlife crossings, such as the new Wallis Annenberg Wildlife Crossing over the 101, will hopefully give the mountain lions a safer option for roaming, though the main goal is to promote gene flow between lion populations, Blakey says (SN: 5/31/16). In a landscape where fire, humans and highways combine, it’s good to have somewhere to run.

What’s the matter?
The proposed Windchime experiment plans to use only gravity to detect some types of dark matter. Ultrasensitive sensors would be jostled by the gravitational forces of a dark matter “wind” passing by Earth, James R. Riordon reported in “Gravity could aid dark matter search” (SN: 9/10/22, p. 14).

Since dark matter is affected by gravity, reader David Goldberg asked if dark matter orbits the Milky Way’s center just like our solar system does. If the two move together, how would there be a dark matter wind to detect?

It’s possible that dark matter circles the Milky Way’s center at least a little, though it’s hard to say for sure because no one has been able to measure the elusive stuff yet, Riordon says. But to search for dark matter using the Windchime method, it doesn’t really matter whether the mysterious substance moves with the galaxy, he says. That’s because as the sun circles the Milky Way’s center, Earth is also orbiting the sun. Even if the sun happens to move with the same velocity as nearby dark matter, the direction of Earth’s velocity changes over the course of a year, Riordon says. So we should sense the pull of a dark matter wind that shifts with Earth’s seasons.

What’s more, as the planet spins on its axis, the direction of the surface’s movement relative to the galaxy changes throughout the day. “It’s a little like a fish swimming in the ocean,” Riordon says. “Even though the water in general moves with Earth, as a fish swims in various directions, the creature will experience a flow of water relative to its own motion.”

Reader Jack Ryan wondered why, despite its gravitational attraction, dark matter doesn’t form stars, planets and other celestial bodies.

“Because no one knows what dark matter is, we can’t say for certain that it can or cannot form globs or come in very massive particles,” Riordon says. “It’s something that researchers like those on the Windchime team are looking out for.”

For normal matter to create asteroids or planets, it must experience some force beyond gravity, Riordon says. For instance, if two rocks collide in space, electromagnetic forces would prevent them from simply passing through each other. This would then allow gravity to hold the two rocks together. And if the concentration of matter continues to build up, then an asteroid or a planet could eventually form.

Some physicists hope that dark matter experiences other forces, but gravity is currently the only one known to affect it. “If a dark matter particle that only experiences gravity approaches a rock, a planet or another dark matter particle, it would glide right through because there is no force that can stop it,” Riordon says. “Gravity can pull dark matter into a halo, but on its own, it probably can’t stick dark matter together.”
Correction
A line dropped from our feature “Island lessons” (SN: 9/24/22, p. 22). At the end of Page 26, the full sentence should have read: Saban native Dahlia Hassell-Knijff got a degree in biology in Mississippi, then returned to the island, where she oversees projects at the regional Dutch Caribbean Nature Alliance.

In the fall of 2020, the world was staggering under the attack of the SARS-CoV-2 virus. In the United States, more than 4 million cases were reported in November, more than double the number in October. Hospitals were overwhelmed. On the Thursday before Thanksgiving, 1,962 people died.

Now, despite more than 1 million deaths in the United States and more than 6 million worldwide, it’s almost easy to forget that the pandemic’s assault continues. That is, until you hear Belinda Hankins’ story.

Hankins has been diagnosed with long COVID, a collection of symptoms that can include crushing fatigue, brain fog, pain and dizziness and that may affect 1 in 5 people infected with SARS-CoV-2, according to one conservative estimate. She talked with Science News staff writer Meghan Rosen during her appointment at the long COVID clinic at the Johns Hopkins Bayview Medical Center.

“For months we’ve heard estimates about how many people have long COVID,” Rosen told me. “I was interested in going beyond the stats to find out what it’s like for the patients and doctors living with this.”

That effort involved talking with doctors who are trying to figure out how to treat the symptoms of long COVID when the cause is still unknown. And talking with Hankins. “I thought it was extraordinary that [she] let me into her appointment,” Rosen said. “It’s just so generous and so brave.”

I share Rosen’s gratitude. Asking someone in the midst of a life-altering illness to talk with a journalist is a big request. I always worry that people might feel pressure to participate, and I want to be sure that they’ve had time to think through the implications of going public with personal information. Hankins was clear about why she said yes. “She wanted to share her story because a lot of people in her life don’t know what long COVID is and why she’s still so sick,” Rosen said.

In reporting, Rosen brings both her empathy and her serious science chops. She has a Ph.D. in biochemistry and molecular biology and is a graduate of the science journalism program at the University of California, Santa Cruz. She explored careers in biotech but decided that wasn’t the right fit. She wanted to write about health and medicine.

This is actually Rosen’s third stint at Science News: first as an intern, then as a reporter, and now back on the beat after five years of doing communications work for the Howard Hughes Medical Institute. We’re glad she’s back. Not only is she tackling complex issues surrounding COVID-19, including how U.S. public health guidelines affect kids in school (SN Online: 8/19/22), she’s also been sharing her delight in science. That includes stories on genetic variants linked to uncombable hair in children (SN: 10/8/22 & 10/22/22, p. 5); an unusual “snough” call that zoo gorillas appear to have invented to get zookeepers’ attention (SN Online: 8/10/22); and a new robotic pill designed to deliver drugs by scrubbing away mucus in the intestines.

Yes, science is serious and important, but it’s also crazy fun. I don’t think I’m ready to sign up for the robotic intestinal scrub brush, but I sure do enjoy finding out about it.