A new biohybrid fish swims using human heart cells beating in its tail. Michael Rosnach, Keel Yong Lee, Sung-Jin Park, Kevin Kit Parker. 2 / 2.

Scientists have discovered the world’s oldest heart in a 380 million-year-old fossil of a jawed fish. Researchers from Curtin University in Australia found the “beautifully preserved” heart ...

The fish moved autonomously for over 108 days, which is equivalent to 38 million beats, the study states. Because heart cells constantly rebuild themselves, which takes about 20 days, Parker tells ...