A heart attack will leave a permanent scar on a human heart, yet other animals, including some fish and amphibians, can clear cardiac scar tissue and regrow damaged muscle as adults. Scientists have ...

As people age, muscles naturally lose mass and strength, a condition known as sarcopenia. The decline can make everyday activities harder and increases the risk of falls, disability and early death.

You bring home a fresh fish, ready to fry or curry, and notice a strip of darker flesh running near the spine or along the sides. It looks reddish brown or gray, very different from the flaky white ...