What is Evolution? Chapter 4.1 and 4.4

What conditions in the environment cause these 2 examples to survive and develop over thousands of years?

Locate the animal

Evolution Genes control the inherited traits of organisms. Genes control the inherited traits of organisms. Evolution can only occur when the gene pool of the population changes. Evolution can only occur when the gene pool of the population changes.

Evolution The 1st organisms were very simple and have become complex over billions of years. The 1st organisms were very simple and have become complex over billions of years. Species  group of organisms that look Species  group of organisms that look alike & can reproduce among themselves.

Evolution Many species have become extinct, while others have taken their place. Many species have become extinct, while others have taken their place. Japanese Wolf Wolf Japanese Wolf Wolf

Evolution Evolution -process by which species change over time.

Adaptations All organisms have adaptations which are traits that help them live in a certain environment. All organisms have adaptations which are traits that help them live in a certain environment.

Adaptations help organisms get food, avoid predators, reproduce, move from place to place, etc. Structural Adaptations Appearing camouflaged Appearing camouflaged Webbed feet of a duck Webbed feet of a duck Long trunk of an elephant Long trunk of an elephant Behavioral Adaptations Opossums play dead Opossums play dead A spider’s web spinning A spider’s web spinning Bird’s courting dance Bird’s courting dance

Mutation A sudden change in a gene is called mutation. A sudden change in a gene is called mutation. If the mutation is helpful, it will be kept and passed onto future generations and the species will change. **A NEW SPECIES** If the mutation is helpful, it will be kept and passed onto future generations and the species will change. **A NEW SPECIES** If the mutation is harmful, the individual organism will die without passing on the trait. If the mutation is harmful, the individual organism will die without passing on the trait.

Charles Darwin’s Theory of Evolution Natural Selection Natural Selection Nature favors the survival of organisms that are best suited/adapted for survival in their environment. Nature favors the survival of organisms that are best suited/adapted for survival in their environment.

Parts of Natural Selection Overproduction Overproduction Not all offspring will survive due to food supply, living space, or predators. Not all offspring will survive due to food supply, living space, or predators.

Parts of Natural Selection Struggle for Existence Struggle for Existence Competition among a species to survive. Only a few will reproduce and others will die. Competition among a species to survive. Only a few will reproduce and others will die.

Parts of Natural Selection Variation Variation Offspring are not alike. They have different traits. With traits favorable to their environment, they are the ones who will survive. Offspring are not alike. They have different traits. With traits favorable to their environment, they are the ones who will survive. Faster Faster Stronger Stronger Colors Colors

Parts of Natural Selection Survival of the Fittest Survival of the Fittest Some variations of an organism make them better suited for the environment and they will survive. Some variations of an organism make them better suited for the environment and they will survive.

Parts of Natural Selection Evolution of New species Evolution of New species Organisms with favorable traits will continue to survive and pass on these traits to their offspring. The organism with the unfavorable traits will die. Over many generations, the changes can result in the appearance of a Organisms with favorable traits will continue to survive and pass on these traits to their offspring. The organism with the unfavorable traits will die. Over many generations, the changes can result in the appearance of a new species. new species.