Alzheimer's Rise - Evolving Eyes - Altering Temperatures - Caribou Antlers

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Feb 25, 2026, 6:26:29 AMFeb 25

https://www.nature.com/articles/d41586-026-00564-2

China is waging war on Alzheimer’s. What can its approach teach the rest of the world?

Rachel Fieldhouse

Alzheimer’s disease is about to become a big problem for China. Nearly 30% of all people with the condition or related forms of dementia already live in the country. And with its ageing population and falling birth rate, the burden on health and social welfare is expected to multiply dramatically in the coming decades.

The Chinese government has responded with programmes and funding that are aimed at improving screening, diagnosis and treatment of Alzheimer’s disease by 2030. And the research has started to take off.

Scientists have been working on new drugs and innovative — if controversial — surgical techniques. The government has also encouraged the development of drugs derived from traditional Chinese medicine. And researchers are accelerating the search for biological markers that precede the onset of Alzheimer’s disease, including genetic contributors, which could explain how the condition develops and reveal the best way to identify it early.

Although the investments don’t yet match the level of funding in the United States, the improving quality and quickening pace of clinical and preclinical research has attracted attention from researchers around the world.

“Maybe China is the next place that will take the lead,” says John Hardy, a neurogeneticist at the UK Dementia Research Institute in London, who is also affiliated with the Hong Kong Center for Neurodegenerative Diseases.
Treating the root of the problem

Nearly 17 million people in China had Alzheimer’s disease and related dementias in 2021 — about 9 in 1,000, according to a report published last year1. Projections suggest that this number could reach as high as 66 million by 2050 (see ‘Dementia’s rise’) or even exceed 100 million by then2,3. The problem is compounded by China’s low fertility rate, which means that there will be fewer people of working age to support the growing population of older individuals with debilitating conditions.

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https://www.nytimes.com/2026/02/23/science/evolution-vertebrate-eye.html

The Rise of Eyes Began With Just One

By Carl Zimmer

Look at just about any vertebrate and you’ll see two eyes looking back at you. Falcons circling overhead have two eyes, just like hammerhead sharks roving through the ocean.

Scientists have long puzzled over how the vertebrate eye first evolved. A pair of new studies suggest a strange beginning: Our invertebrate ancestors 560 million years ago were cyclopes, with a single eye at the top of their head, scientists now propose, that only later split in two.

Charles Darwin fretted a lot about the exquisite complexity and sophistication of the vertebrate eye as he developed his theory of evolution. “The eye to this day gives me a cold shudder,” he confided to his friend, the American botanist Asa Gray, in 1860. Somehow evolution had produced the eye from many parts, such as the lens and retina, through tiny changes through the generations. Darwin couldn’t say for sure what that sequence of changes was.

But he was encouraged by the diversity of simpler eyes among invertebrates. Some are mere lumps of pigment that detect light; others are simple cups lacking lenses.

“When I think of the fine known gradations,” Darwin wrote to Gray, “my reason tells me I ought to conquer the cold shudder.”

Yet opponents of evolution continued to cast doubt on the idea that eyes could evolve. Even in the 1990s, creationists claimed that natural selection would need many billions of years to produce an eye — far more time than life has existed on Earth.

Dan-E. Nilsson, a neurobiologist at Lund University in Sweden, grew so annoyed by these claims that he estimated how long it would actually take for a patch of light-sensitive cells to evolve into an image-forming eye. “I thought, Heck, that’s an easy calculation, let’s do that,” Dr. Nilsson recalled.

In 1994 he and Susanne Pelger, a colleague at Lund, concluded that an image-forming eye could evolve in just a few hundred thousand years. “It’s not precise in any way at all, but it goes to show that there is plenty of time for eyes to evolve,” Dr. Nilsson said.

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https://knowablemagazine.org/content/article/living-world/2026/why-heterothermic-animals-control-their-body-temp

The strange animals that control their body heat

By Hannah Thomasy

In 1774, British physician-scientist Charles Blagden received an unusual invitation from a fellow physician: to spend time in a small room that was hotter, he wrote, “than it was formerly thought any living creature could bear.”

Many people may have been appalled by this offer, but Blagden was delighted by the opportunity for self-experimentation. He marveled as his own temperature remained at 98 degrees Fahrenheit (approximately 37 degrees Celsius), even as the temperature of the room approached 200°F (about 93°C).

Today, this ability to maintain a stable body temperature — called homeothermy — is known to exist among myriad species of mammals and birds. But there are also some notable exceptions. The body temperature of the fat-tailed dwarf lemur, for example, can fluctuate by nearly 45°F (25°C) over a single day.

In fact, a growing body of research suggests that many more animals than scientists once appreciated employ this flexible approach — heterothermy — varying their body temperature for minutes, hours or weeks at a time. This may help the animals to persist through all sorts of dangers.

“Because we’re homeotherms, we assume all mammals work the way we do,” says Danielle Levesque, a mammalian ecophysiologist at the University of Maine. But in recent years, as improvements in technology allowed researchers to more easily track small animals and their metabolisms in the wild, “we’re starting to find a lot more weirdness,” she says.

The most extreme — and well-known — form of heterothermy is classic hibernation, which has been most extensively studied in critters who use it to save energy and so survive the long, cold winters of the Northern Hemisphere. These animals enter long periods of what scientists call deep torpor, when metabolism slows to a crawl and body temperature can drop to just above freezing.
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https://www.scientificamerican.com/article/female-caribou-grow-antlers-as-a-built-in-postbirthing-snack/

Female caribou grow antlers as a built-in postbirthing snack

By Emma Gometz

Caribou, large deer that are native to the northernmost parts of the world (and sometimes called reindeer), are the only deer whose females grow antlers. In a study published today, researchers observed behavior that might explain why: female caribou appear to gnaw on shed antlers as a kind of postbirthing supplement.

Caribou migrate huge distances every year between the places where they graze during the winter and the grounds where they calve in the spring. They can walk thousands of miles per year and likely have the longest terrestrial migration of any animal. Caribou mothers complete these extremely long migrations with antlers on their head and a calf in their womb. The period is very nutritionally demanding for them but culminates with a reserve stock of supplements when they need it the most.

The researchers behind the new study figured this out when they observed bite marks in more than 80 percent of the 1,500 caribou antlers that littered the part of the Arctic National Wildlife Refuge in northeastern Alaska where the deer give birth.

“[Caribou] are just really going after the antlers. They are highly selective,” says study co-author Joshua Miller, a paleoecologist at the University of Cincinnati.

Female caribou shed their antlers just days before giving birth. Miller and co-author Madison Gaetano, a conservation paleobiologist, say that the findings suggest that female caribou are essentially banking nutrients in the form of antlers before they give birth and then gnawing on their freshly shed antlers to get a boost of protein, calcium and phosphorus they need to make up for having less time to graze as they nurse their calves.

https://www.nytimes.com/2026/02/24/science/susan-e-leeman-dead.html

Susan Leeman, 95, Dies; Explored How the Brain Influences the Body

By Delthia Ricks

Susan E. Leeman, who helped reshape scientific understanding of how the brain sends chemical signals throughout the body, did not hesitate to leave the laboratory when her research demanded it — even if it meant visiting slaughterhouses.

In the late 1960s, while running a small lab at Brandeis University, she was trying to isolate a stress hormone and needed large quantities of the bovine hypothalamus, a cow’s version of the structure found deep in all mammalian brains. When supplies ran short at a local meatpacker in Boston, Dr. Leeman traveled to Chicago, home at the time to the sprawling Union Stock Yards, to secure fresh tissue.

What ultimately emerged was not the hormone that she sought but an elusive chemical called Substance P.

Discovered decades earlier but never fully understood, it was finally identified by Dr. Leeman in 1970 as a neuropeptide, released by cells in the brain or spinal cord in response to pain. Three years later, she identified another neuropeptide. The two discoveries established her as a leading figure in neuroendocrinology.

Dr. Leeman died on Jan. 20 in Manhattan, at the home of her daughter Eve Leeman, where she had been living. She was 95. Her death was confirmed by another daughter, Jennifer Leeman.

Although Substance P was identified in 1931 by Ulf von Euler and John Gaddum, researchers working in London, it was Dr. Leeman who discovered that it was a neuropeptide — a tiny, protein-like molecule released by neurons, or nerve cells in the brain and spinal cord, that transmits signals to target tissues.

It was the first neuropeptide discovered in what would become a large class known as tachykinins.

Dr. Leeman found that Substance P relays pain signals and amplifies the sensation of pain by triggering inflammation. It has since been linked to chronic pain syndromes, arthritis pain and migraines.