University of Quebec

Hands were one of the key things fish needed to evolve before moving out of the water and becoming tetrapods like us, and a new fossil study pinpoints a "missing link" in the evolutionary tree. Meet Elpistostege, from nearly 400 million years ago.

Detection of E. coli bacteria involves tests that typically take several hours, and must be performed in a lab. That could soon change, however, as scientists have developed a portable sensor that can do the job in 15 to 20 minutes. ​