Ecology & evolution
New Cavefish Species Challenges View of Caves as Evolutionary Dead Ends
Yale-led researchers described Typhlichthys styx, a blind cavefish, and found that underground aquifers helped split Southern cavefish into separate species about 8 million years ago.
Survival of the Fittest? What Natural Selection Really Says
Natural selection is one of the basic mechanisms of evolution, and it is often misunderstood. Three sources explain what it needs, how it works and what it does not mean.
What Is an Ecosystem? Living Things, Nonliving Things and the Links Between Them
An ecosystem is a community of organisms together with the air, water and soil they interact with. Agencies and educators explain how energy and materials move through them.