The researchers use a mass spectrometer to measure with very high accuracy the mass of molecules derived from the microbes in a community. Then they use a newly developed software program that allows them to link microbes with their substrates.

The basis for connecting microbe and substrate are so-called carbon stable isotope ratios -- the ratios between naturally occurring forms of carbon with different masses. Nature contains both carbon-12, the most abundant form, and carbon-13, which has one more neutron than carbon-12. Each material has a very specific ratio of these two isotopes, which essentially can be used as the fingerprint or signature of the material. The new algorithm links the carbon isotope ratios of the substrates that are available to microbes in a given environment to the ratios found in the microbes themselves. Read more.

Back in 1929, a team of researchers discovered the fossilized remains of Ichthyostega, a tetrapod that was believed to be among the first creatures to walk on land. Since that time, similar types of remains have been found in places like Greenland and China. Study has shown the creatures were able to live both on land and in water—they had four legs, tails for swimming and gills. But until now, scientists reported difficulty in figuring out if the water they came from was fresh or salty (suggesting an ocean existence). In this new effort, the researchers tested 51 ancient fossilized tetrapod bones as a new way to find the answer to this question. Read more.

More than 45 small radioactive electricity generators were in Antarctica between 1961 and 2015, an investigation by Stuff has found.

The devices, called Radioisotope Thermoelectric Generators (RTGs), powered remote automatic weather and other scientific data collection efforts. Some moved through New Zealand air and sea ports, especially in Christchurch.

The Antarctic RTGs were powered by small amounts strontium 90, a radioactive isotope with a half life of 28.8 years. They were typically shielded by depleted uranium to protect human and other life from ionising radiation.

RTGs transformed heat produced by radioactivity into small amounts of electricity, enough to power a simple weather station for 10 years or more. Read more.

Not many people still call California the “Bear State,” but before the gold rush, before the state became known for technology, agriculture, and sunny beaches, before the rivers were dammed and the forests were logged, California was home to grizzly bears.

California grizzlies, a subspecies of the North American brown bear, have been extinct for nearly a hundred years  the last grizzly recorded in the state vanished in the Sierra Madre mountains in 1924, and the bulk of the population was already gone by the end of the 1800s. But a new project from the California Grizzly Research Network, a group of researchers from UC Santa Barbara and the La Brea Tar Pits/Natural History Museum of Los Angeles County, seeks to trace the state’s history and biological legacy using tiny fragments of grizzly bear bone. Read more.