A parasite that can alter animal behavior is changing the habits of infected wolves in Yellowstone, increasing aggression and goading them into taking greater risks.
A global drop in oxygen levels about 550 million years ago led to Earth's first known mass extinction, new evidence suggests.
Staving off the worst impacts of climate change means preventing global temperatures from rising more than 1.5 degrees Celsius above preindustrial levels. But CO2 emissions are so high that we are slated to cross that line within a decade.
The rapid decline of the British-Irish Ice Sheet thousands of years ago may hold lessons for how melting ice sheets in Greenland and Antarctica will influence sea-level rise in the future.
A megalodon tooth found suspiciously close to two fractured whale vertebrae may reflect one small whale's heroic escape from the jaws of a giant prehistoric shark.
We are not yet sure how long COVID-19 immunity lasts, but experts agree that there is little cause for alarm and that a vaccine will likely still be successful.
Scientists use herd immunity to describe the point at which a population is sufficiently immune to a disease to prevent its circulation.
The most important ways to prevent transmission are still the same, whether SARS-CoV-2 spreads via tiny droplets or larger ones.
The first few weeks of a keto diet may come with a spate of flu-like symptoms, including nausea, fatigue and dizziness, according to a new study.
A new study finds that resting heart rate can vary between individuals by up to 70 beats per minute, calling into question how physicians use one of the most fundamental vital signs.
Although CDC data suggest an increase in life expectancy as of 2018, the U.S. continues to lag behind comparable countries.