In regressive evolution, organisms lose complex features and can appear to evolve "in reverse." But evolution doesn't retrace its steps, experts said.
In the context of a disease, the transition from "epidemic" to "endemic" means a pathogen is no longer causing outbreaks but isn't disappearing.
Billions of years ago, wind, heat and the rotating Earth formed currents just as they're produced today — but their paths would have been wildly different.
New fund would aid responses to floods, fires and storms. But a failure to address warming and greenhouse gas emissions undercuts the funding success, critics say.
A United Nations report warns of imperiled glaciers at iconic World Heritage sites — but climate action could save most of them.
The biggest blasts come from above, while volcanic eruptions and human-caused detonations have also unleashed incredible levels of energy.
Hurricane Katrina was the most expensive hurricane in history, while a 1780 storm killed the most people of any hurricane.
Organisms that reproduce quickly can quickly evolve into new species, while geographic barriers can lead to new species formation over tens of millions of years.
A subduction zone is a collision between two of Earth's tectonic plates, where one plate sinks into the mantle underneath the other plate.
Panthalassa, a single world ocean surrounding the supercontinent Pangaea, would have stretched at least 1,800 miles (3,000 kilometers) wider than the Pacific.
The Cretaceous period lasted approximately 79 million years, and ended with a major extinction event about 66 million years ago.
Sharks are a diverse group of often-misunderstood fish. Learn more about these predators, including their evolution, habitat, diet and behavior.
Forests took millions of years to evolve after the first land plants arrived, waiting for precursors to roots and branches to arrive and for CO2 levels to get just right.
The reasons for prehistory's roster of bigger animals range from dinosaur physiology to mammalian social groups.
Dolphins can recognize each other by the taste of their pee, and urine-tasting behavior is also linked to "name" recognition.
Reference Ichthyosaurs, marine reptiles that resembled dolphins and could rival blue whales in size, coexisted with dinosaurs.
To produce vodka, you must first ferment a foodstuff that contains sugar or starch, then distill the product to increase its alcohol content. But what is vodka made from?
Reference Solar panels convert sunlight into electricity, providing an alternative, renewable energy source
RNA keeps some of life's most important processes humming, from building your body's proteins to silencing genes.
Taxonomy is the science of naming, defining and classifying organisms into evolutionarily related groups. It gives biologists a common language.
Even an extremely dead apex predator deserves a beautiful view of the night sky — particularly one that reminds them of home.
From a nuclear commander to a Harvard-educated refugee, STEM-trained candidates are shaking up politics.
U.S. cities committed to the Paris climate accord after President Trump announced the country's exit. But how much can urban areas do?