In May 2014, a group of recreational divers spotted an adult lionfish -- the voracious invader Pterois volitans -- in the rocky reefs of southeastern Brazil. A single fish caught with a hand spear off the Brazilian coast is making big waves across the entire southwestern Atlantic. In May 2014, a group of recreational divers spotted an adult lionfish--the voracious invader Pterois volitans--in the rocky reefs of southeastern Brazil. A group of researchers, including scientists from the California Academy of Sciences, used genetic analysis to link the lionfish to the infamous Caribbean population of invaders. In light of a separate study detailing the lionfish penchant for eating critically endangered Caribbean reef fish, news of lionfish in Brazilian waters raises alarm for Atlantic reefs and the region's already-threatened marine life. The discovery is published this week in PLOS ONE.

This image shows a colony of Trichodesmium. Scientists have found something they can't quite explain in one of the most barren environments on Earth: a bacterium whose DNA sequence contains elements usually only found in a much higher organism.

In the most comprehensive study ever on the impact of smoking on cardiovascular disease in older people, epidemiologist Dr. Ute Mons from the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) analyzed 25 individual studies, compiling data from over half a million individuals age 60 and older.