1. EVIDENCE OF EVOLUTION

2. EVOLUTION - Evolution is when a population of organisms change over time. -Darwin proposed the idea that evolution happens through natural selection.

3. DARWIN’S EXPLANATION FOR EVOLUTION His careful studies of plants and animals led him to state that evolution by natural selection explained how populations of organisms evolve. Natural selection is a mechanism for changes in populations. This occurs when organisms with favorable variations for a particular environment survive, reproduce, and pass these variations on to the next generation.

4. Organisms with less-favorable variations are less likely to survive and pass on traits to the next generation. Natural selection is when organisms with good genes live and pass down their genes and organisms with bad genes die out.

5. II. NATURAL SELECTION - Natural selection is the way evolution happens. That is, natural selection is how organisms change over time. -Natural selection is when organisms with good genes live and pass down their genes and organisms with bad genes die out.

6. NATURAL SELECTION AND ADAPTATIONS Adaptation is any trait that helps the chances of survival and reproduction. 2 forms of adaptations 1.Structural Adaptations Some structural adaptations are used for defense against predators ex. Thorns in plants Spines in animals

7. STRUCTURAL ADAPTATIONS

9. Other forms of structural adaptations -- Mimicry – provides protection by an organism copying the appearance of another species. -- Camouflage – allows for organism to blend with its environment

10. MIMICRY

12. CAMOUFLAGE

15. 2. Physiological adaptations are changes in an organism’s metabolic processes. This type of adaptation can happen rapidly. ex. bacteria with penicillin, and also insects and weeds.

17. EVIDENCE FOR EVOLUTION 1. Fossils show changes over time. - Fossils provide a record for earlier life.

18. FOSSILS -Fossils are evidence for evolution because they give a record of how organisms have changed over a long period of time. Camel Evolution Age Organism Skull and Skull and teeth teeth Paleocene 65 million years ago Eocene 54 million years ago Oligocene 33 million years ago Limb Limb bones bones Miocene 23 million years ago Present

19. 2. Anatomical relationships – similarities in the structure of an organism. Evidence that organisms evolve from a common ancestor. Homologous structure are body parts that are similar in structure, in function, or in both structure and function.

20. HOMOLOGOUS STRUCTURES

22. Analogous structures are body parts that are similar in function, but different in structure. ex. Wings of a bird and a butterfly Vestigial structures any body structure that is reduced in function. May have been of use to an ancestor. ex. flightless birds (ostrich), appendix in humans

23. 3. Embyological Development shows evolution from a common ancestor. ex. The presence of gills and tails in the early stage of all vertebrate embryos. 4. Genetic Comparisons may also show relationship of different species. Can also helps us tell how closely related or how different species are ex. Order of DNA and RNA nucleotides