Kangaroos evolved thick knee cartilage to absorb shock, a feature that scientists are investigating for potential human arthritis treatment and prevention strategies.

For scientists pursuing the cure for arthritis, the holy grail of discoveries lies in how to regrow healthy cartilage inside human joints. While this feat has so far resisted our best scientific attempts, there are plenty of other human tissues—such as the liver and fingertips—that will successfully regenerate.

The human knee is a remarkably complex structure carrying the full weight of the body throughout a person's life while allowing a number of complex twists, flexes, and extensions. It's also one of the body's biggest weaknesses—the location of chronic pain and replacement surgeries for millions of Americans.

Osteoarthritis is the most common type of arthritis, resulting from age-related degeneration of the soft cartilage lining between bones. As this layer breaks down, the normal smooth motion between bones is lost and the joint becomes painful.

A particularly difficult arthritis subtype is rheumatoid arthritis, a painful condition provoking a vicious cycle of joint inflammation, destruction, and dysfunction. It begins with a misfiring of the patient’s own immune system—for unknown reasons, it identifies joint and cartilage cells as foreign, initiating an attack to eliminate the supposed "invaders."

It is estimated that roughly half a billion people worldwide are currently suffering from arthritis. This resource explores five of the most promising recent advancements in arthritis research as scientists work toward improved treatments and continue the search for a cure.

Using CT scans and advanced pathology techniques, paleopathologists have identified respiratory illnesses, malignant osteosarcoma, and other diseases in dinosaurs. The research has helped show how many of these ailments are not exclusively modern phenomena.

A new biomechanical study analyzing four T. rex specimens, including the famous "Sue" at Chicago's Field Museum, found the dinosaur used a "distal-first" foot strike, described as landing on its toes before its heel, similar to a modern ostrich. The technique improved stride efficiency and shock absorption, letting adults reach speeds up to 14 mph, while younger, lighter T. rexes could sprint closer to 25 mph.

The average blood pressure of a giraffe is about double that of a human, yet they don't suffer from the symptoms of high blood pressure that humans do: stiffening of the left heart ventricle, shortness of breath, fatigue, or swollen legs and ankles. This article explains how giraffes have evolved to have the "biological equivalent of support stockings."

More than 28 million people may go running in the US every week, yet people often get hurt—especially with knee injuries—and this podcast explores the science on what happens to our bodies when we run and the effects on our muscles and joints. It also discusses safety tips, including the need to only add more distance to your runs in tiny increments, and that strengthening glute muscles via single-leg glute bridges may be particularly protective against injuries.

Conservationists in Namibia have found that airlifting rhinos upside down is actually better for their health than lying them down on stretchers. A study by Cornell University found that rhinos have higher blood oxygen levels when upside down, which is critical for their survival during transport. The upside-down position also allows the rhino's spine to relax, which can help to prevent injuries. This new finding could revolutionize the way that rhinos are moved.

We're not sure yet. Researchers at the University of California San Francisco are studying why some conditions and behaviors, such as low-oxygen environments and exercise, benefit the aging process, hoping to reveal potential health applications. Some of this research focuses on klotho, a naturally occurring age-regulating hormone named after the Greek Fate Clotho. Animal studies on klotho brain injections found subjects had improved memory recall and age-related degeneration resistance.

Rheumatoid arthritis is an autoimmune condition leading to breakdown and inflammation of multiple joints throughout the body. This academic article provides an updated deep dive into our current cellular understanding of rheumatoid arthritis, how it is diagnosed, and the variety of medications available for treating this painful condition.

Nestled under archaeology lies bioarchaeology, which involves the study of bones, human or animal. This subfield recently birthed another field of study: paleo-oncology. Paleo-oncology looks for cancer and related biomarkers in bioarchaeological remains. This TED article explains how this nascent multidisciplinary field challenges the idea that cancer is modern.

There is now ample evidence to back the centuries-old hypothesis that exercise is critical to human health. This review article explores the latest discoveries in exercise science, including how exercise is intrinsic to maintaining our organ systems throughout life.

Paleontologists analyzed the fossilized eye and ear structures of 16 theropods, finding that some had owl-like hearing and huge pupils. These characteristics are consistent with modern-day nocturnal species, including nightjars and geckos.

For years, scientists have been wondering why wombat poop is cube-shaped (yes, really). Now, they say they have got to the bottom of the mystery.

Although scientists do not know if allergies manifest among wild animals—and if animals can survive with them—in a zoo setting, veterinarians have observed zoo animals with common allergy symptoms, including itchiness, crusty skin, and runny eyes. Veterinarians have identified Asian elephants with pollen allergies and at least one jaguar with an allergy to fleas.

Shells for hermit crabs, wheelchairs for guinea pigs and dogs, and horseshoes for improved running performance have been created using 3D printers. Other artificial body parts made using this technology include a jaw for a loggerhead turtle, a beak for a toucan, and a tail for an American alligator.

Success in high-level sports after age 30 relies on physical fitness and building brain resilience through deliberate training, recovery, and stress regulation. This creates a feedback loop where body and mind reinforce each other.

When muscles contract, they release ‘hope molecules’ (myokines) such as IL-6 and irisin. These proteins then travel through the bloodstream to reduce inflammation, improve insulin sensitivity, and even support brain repair. This piece illustrates how movement triggers a systemic healing cascade throughout the human body.

As part of a post-WWI initiative to turn veterans into farmers, soldiers were given plots of land. After emus were found damaging the farmland, three men were sent to handle the flightless birds. These men ended up losing to the second-largest bird species in the world and potentially exacerbating crop losses by sending swaths of the birds running and trampling over wheat.

Cuts to human skin take twice as long to heal compared to chimps and other mammals. Scientists argue this is due to the reduced number of hair follicles on human bodies. Hair follicles contain stem cells which help repair skin cells faster, so as humanity shed its hair over time, so to speak, it also slowed its wound healing.

Emus are flightless birds native to Australia, second only to ostriches in size among avians. Reaching up to six feet and weighing more than 100 pounds, the grayish-brown emu can run 30 mph, lives in small flocks, and travels widely for food and water as a nomad. Learn more about the emu's many delightful quirks in this irreverent and informative podcast.

The protein KRAS, mutated in many cancers, was deemed ‘undruggable’. Now scientists are hoping to save lives with a batch of new compounds that target it.

Horseshoe crabs are older than dinosaurs and have survived five mass extinctions that wiped most life from the planet. But it's only now that their future as a species is in danger. This blood, worth about $60,000 per gallon, is hyper-sensitized to certain bacteria that are fatal to humans. This 17-minute podcast dives into humanity's pursuit of horseshoe crab blood, a "somewhat magical" mixture heavily relied on by the pharmaceutical industry.