What do you notice about the different birds?

What do you notice about the environments?

Darwin’s Explanation Darwin proposed that animals evolved to fit their environments.

Darwin’s Explanation Darwin realized that animals have many offspring and some don’t survive. The survivors are better suited to their environment.

He called this process…. Natural Selection

Theory of Natural Selection 1. Overproduction Organisms have many offspring, but not all of these offspring will survive. Example: A female rabbit can produce up to seven kittens in a litter, but they don’t all survive to become adults.

Theory of Natural Selection 2. Genetic Variation Every individual is slightly different Some traits make it easier to survive. When these individuals survive, they pass their traits on to their offspring. Example: Below are three different colourings and skin patterns found in the giraffe.

Theory of Natural Selection 3. Struggle to Survive there are limited resources (water, food and space), so some organisms won’t survive.

Theory of Natural Selection 4. Decent with Modification Those who are well adapted (good traits) survive and reproduce to pass on their traits.

Survival of the Fittest The individuals that are best adapted to their environment are most likely to survive and reproduce Those individuals that are the least well adapted do not survive long enough to breed.