The Cretaceous–Paleogene (K–Pg) mass extinction event, marking the boundary between the Cretaceous and Paleogene periods approximately 66 million years ago, stands as one of the most profound ...

Speciation and extinction are the twin engines that have sculpted the diversity of life on Earth. Speciation, the process by which new species arise from ancestral populations, is driven by a mixture ...

At some point in the deep past, humans may have come frighteningly close to disappearing altogether. Here’s what we know, ...

Imagine an asteroid striking Earth and wiping out most of the human population. Even if some lucky people survived the impact ...

About 445 million years ago, Earth’s oceans turned into a danger zone. Glaciers spread across the supercontinent Gondwana, and shallow seas shrank fast.

One of Earth’s earliest mass extinctions wiped out most ocean life during a sudden global ice age. From the ruins, jawed vertebrates survived, diversified, and transformed the course of evolution.

Contributed by Kea Giles, Managing Editor, GeologyBoulder, Colo., USA: Mass extinctions are extremely catastrophic events on Earth. Throughout Earth's ...

Ancient sloths ranged in size from tiny climbers to ground-dwelling giants. Now, researchers report this body size diversity was largely shaped by sloths’ habitats, and that these animals’ precipitous ...

Mass extinctions are extremely catastrophic events on Earth. Throughout Earth's evolutionary history, numerous mass ...

For decades, the asteroid that ended the reign of the dinosaurs has stood as a symbol of total planetary devastation. But hidden within the chaos it unleashed was the seed of a biological rebirth. In ...