• Adaptation - How living things are specialised to suit their environment.
• Evolution - The process by which living things can gradually change over time.
• Inheritance - The process of passing on features from parents to offspring.
• Species - A group of living things with very similar characteristics. They can breed together to make more living things of the same type.
• Variation - The differences between living things in a species.

• It took Charles Darwin, an English naturalist, 20 years to write and publish his original book On the Origin of Species that explained the process of evolution.
• Humans share the same five-fingered bone structure in their hands with lots of other animals that have paws, wings or flippers, such as lemurs and bats.

• Instinct is another important part of natural selection. For example, most birds know they must travel to warmer places to survive during winter.
• There are over 340 breeds of dog, yet they all come from one kind of wild wolf that existed many years ago.