Without variation, evolution cannot happen.

Organisms may have variations that help them survive. If so, they will reproduce and pass those variations on to their offspring. This can lead to the formation of a new species.

One example is the Galápagos finches. Charles Darwin visited the Galápagos Islands in 1835. He was surprised by the number of different finch species that existed in such a small area. Each group of finches was adapted to different regions, sources of food, and lifestyles.

Map by Dave Smith, © UCMP; Finch photos by Gerald and Buff Corsi, © 2003 (Geospiza fortis and Geospiza fuliginosa) and 2005 (Geospiza scandens) California Academy of Sciences.