Oxygen linked with the boom and bust of early animal evolution

Extreme fluctuations in atmospheric oxygen levels corresponded with evolutionary surges and extinctions in animal biodiversity during the Cambrian explosion, according to a new study.

The Cambrian explosion was a crucial period of rapid evolution in complex animals that began roughly 540 million years ago. The trigger for this fundamental phase in the early history of animal life is a subject of ongoing biological debate. Read more.

Scientists Think They've Found the Ancient Neutron Star Crash That Showered Our Solar System in Gold

Two astronomers think they've pinpointed the ancient stellar collision that gave our solar system its cache of precious gold and platinum — some of it, anyway.

In a new study, the duo analyzed the remnants of radioactive isotopes, or versions of molecules with different numbers of neutrons, in a very old meteorite. Then, they compared those values with isotope ratios produced by a computer simulation of neutron star mergers — cataclysmic stellar collisions that can cause ripples in the fabric of space-time. Read more.

Fossils from a Philippine cave may come from a new human-like species

Scientists say Homo luzonensis lived at least 50,000 years ago

In a cave in the Philippines, researchers made a remarkable discovery of fossil bones and teeth. These remains appear to come from a new human-like species. This human relative, or hominid, lived at least 50,000 years ago. Scientists have just dubbed its species Homo luzonensis. They took the name from Luzon, the island on which the fossil remains were found. Read more.

The smell of dark chocolate, demystified

Chocolate is one of the most-consumed treats around the world, and the smell alone is usually enough to evoke strong cravings from even the most disciplined eaters. Much like a fine wine, high-quality dark chocolate has a multi-layered scent and flavor, with notes of vanilla, banana or vinegar. Now, researchers report which substances — and how much of them — make up this heavenly aroma. Read more.

Magic numbers make nickel nucleus stronger

Researchers made magic with nickel, but this was no coin trick

Researchers provide the first direct evidence for a rare kind of atomic nucleus. The special nickel nucleus (78Ni) is an isotope of typical nickel (58Ni), meaning they share the same number of protons but a different number of neutrons. Usually more neutrons make isotopes less stable, but this isotope is special. 78Ni is more tough or rigid than other nickel isotopes with similar numbers of neutrons − it takes more energy to excite 78Ni into a different state. Read more.