HS-LS4-5
Evaluate the evidence supporting claims that changes in environmental conditions may result in: (1) increases in the number of individuals of some species, (2) the emergence of new species over time, and (3) the extinction of other species.
- Fossils
One of the earliest meat-eating mammals was saber-toothed
Millions of years before the evolution of saber-toothed cats, a newly discovered "hypercarnivore" prowled the forests of what is now San Diego.
- Animals
The end of the dinosaurs appears to have come in springtime
Fish fossils from North Dakota suggest when the Chicxulub asteroid devastated Earth, triggering the mass extinction of dinosaurs and other species.
- Archaeology
Our species may have reached Europe while Neandertals were there
Archaeological finds from an ancient French rock-shelter show periodic settlements by both populations, just not at the same time.
- Animals
As the tropics warm, some birds are shrinking
Migratory birds are getting smaller as temperatures climb, studies had showed. New evidence shows dozens of tropical, nonmigratory species are, too.
- Life
Scientists Say: Adaptation
This word refers to a feature of a living thing that helps it better survive in its environment — or the process of that feature evolving in a population.
- Fossils
‘Penis worms’ could have been the original hermits
These soft-bodied critters lived in abandoned shells about 500 million years ago, a new study suggests.
- Earth
Explainer: The age of dinosaurs
Take a trip back to the Mesozoic Era to explore how geologic events, ecosystems and evolution were connected during the so-called age of dinosaurs.
- Animals
Cloning boosts endangered black-footed ferrets
A cloned ferret named Elizabeth Ann brings genetic diversity to a species that nearly went extinct in the 1980s.
- Fossils
Dinosaur families appear to have lived in the Arctic year-round
Fossils of baby dinosaurs in northern Alaska challenge the idea that northern dinosaurs only spent their summers in the high Arctic.
- Animals
Let’s learn about whales and dolphins
Whales, dolphins and porpoises are all cetaceans — mammals that live in water and have a streamlined body similar to a fish.
- Plants
Dinosaur-killing asteroid radically changed Earth’s tropical forests
The asteroid collision initially reduced the diversity in what had been sunny tropical rainforests. In time, the forests would become permanently darker.
- Fossils
An ancient hippo-sized reptile may have been a speedy beast
An Anteosaurus was a hefty reptile with a large snout. Its fossil skull hints that it may have moved fast for its time.
