Discover how living things adapt to their environments and how species evolve over time.
Every living thing has features — called adaptations — that help it survive in its particular environment. A polar bear has thick white fur to stay warm and camouflaged in Arctic snow. A cactus has spines instead of leaves to reduce water loss in the desert. A duck has webbed feet for swimming. These adaptations didn’t happen overnight — they developed slowly over many thousands of generations through a process called evolution. The scientist Charles Darwin, after studying the remarkable variety of animals on the Galapagos Islands in the 1830s, developed the theory of evolution by natural selection. His idea was that within any species, individuals vary slightly. Those whose variations make them better suited to their environment are more likely to survive, reproduce and pass those helpful traits to their offspring. Over many generations, these traits become more common — the species gradually changes, or evolves. This process explains the extraordinary diversity of life on Earth.
