A new surgery treats Alzheimer's as a backed-up brain drain — but McGill researchers say we should be skeptical of the plumbing theory.

A giant rocky exoplanet so dense it shouldn't exist is forcing astronomers to rethink how planets form in the first place.

A 170-million-year-old rocky "mega-Earth" is so dense and large that it shouldn't exist — and astronomers say it breaks the rules of how planets form.

A 2-billion-year-old rock formation is challenging what geologists thought they knew about Earth's ancient carbon cycle — and the disruption it points to was global.

New digs at 11,600-year-old Göbekli Tepe are upending the idea that it was a remote ritual site visited only for ceremonies — not a place people actually lived.

Bones long assumed to mark farming's arrival in Ireland and Britain have been reanalysed — and the dates don't hold up the way prehistorians thought.

The same cause killed 43% of a studied astronaut group — and scientists now think spaceflight itself may be rewiring the heart.

Twenty elephants died mysteriously in Kenya, and wildlife experts are now challenging the cyanide-from-pesticides explanation — so what actually killed them?

Bones labeled "Kerry Cow" for generations have turned out to be ancient bear remains — upending what researchers thought they knew about early Irish prehistory.

Ancient fossils found near Taiwan are reigniting claims about biblical giants — but what does the bone evidence actually support?

One report, four competing theories — and scientists say the bat-to-intermediate-host pathway is already the clear frontrunner for how the virus first jumped to humans.

A single NASA photo from Mars has reignited debate over whether an unidentified object is evidence of life — or just rock and shadow playing tricks.

Nearly 30 dead dogfish sharks washed up on a Jersey Shore beach — and a shark ecologist thinks he knows why this rare mass stranding happened.

A NASA Curiosity rover photo shows a rock formation so jellyfish-like that it's reigniting debate: are we wired to see life where there is none?

Testosterone levels in men are falling, and a University of Michigan professor points to the environment — but is modern life quietly reshaping male biology?

A presidential executive order targeting childhood vaccines rests on a claim scientists have repeatedly tested and rejected — so why does the belief keep driving policy?

GLP-1 drugs shrank depression-linked anhedonia — but researchers are asking whether the same brain blunting could mute joy in healthy people too.

Giant trees were supposed to slow down as they grew taller — now new evidence suggests the biggest ones keep accelerating, defying a decades-old limit theory.

Six years on, no government or lab has cracked COVID's origin — and experts now say a definitive answer may never come.

A major heart drug trial failed to deliver results, putting the inflammation-causes-artery-disease theory — a leading rival to the cholesterol model — under serious pressure.