On February 12, 1809, Charles Robert Darwin was born in Shrewsbury, England. Darwin was a naturalist who in 1820 traveled around the world on the ship Beagle. On his trip, Darwin saw evidence for the theory of natural selection. Natural selection explains that throughout time, plants and animals adapt to their environments as individuals. Better-adapted individuals overtake the whole of the species, because they are more likely to survive.
 
Darwin's theory changed the way we look at life on Earth. Before his time, the world and the things in it were viewed as static, always having been the way they are now. His theory opened people up to the idea that plants and animals had changed in the past, and will continue to change in the future.
adapt
Verb

to adjust to new surroundings or a new situation.

environment
Noun

conditions that surround and influence an organism or community.

evidence
Noun

data that can be measured, observed, examined, and analyzed to support a conclusion.

naturalist
Noun

person who studies the natural history or natural development of organisms and the environment.

natural selection
Noun

process by which organisms that are better -adapted to their environments produce more offspring to transmit their genetic characteristics.