Evolution only occurs when there is a change in gene frequency within a population over time.

1. The central ideas of evolution are that life has a history. It has changed over time and that different species share common ancestors.

2. Evolution only occurs when there is a change in gene frequency within a population over time. 1st generation of Beetle population Many generations later of the same population

3. Gene Pool Any change made in the gene pool over time contributes to evolution

4. What can cause these changes? Mutations- Any change (error) made in DNA during replication

5. Mutation • Mutations are important in how populations change over time because they result in genetic changes to the gene pool.

6. Mutations can cause changes over time, if they cause an inheritable beneficial trait.

7. What can cause these changes? Migration (Gene Flow)- An individual travels to a new population and introduces a new trait.

8. What can cause these changes? Genetic Drift- Random event that changes the allele frequency in a population

9. What can cause these changes? Natural Selection- process of evolution in which traits that result in better fitness of an individual survives to the next generation.

10. The evolution of insecticide resistance is an example of natural selection in action Chromosome with geneconferring resistanceto insecticide Additionalapplications of thesame insecticide willbe less effective, andthe frequency ofresistant insects inthe populationwill grow Insecticideapplication Survivor

11. Natural Selection • the survival and reproduction of the individuals in a population that exhibit the traits that best enable them to survive in their environment. • The Survival of the Fittest

12. What can cause these changes? Mutation Migration/ Gene Flow Genetic Drift Natural Selection

13. Charles Darwin’s Theory of Evolution: 1. Members of a population have inheritable variations.(Inheritance of traits)

14. Why Genetic Variation? If a population was 100% the same… natural selection and genetic drift would have NO effect because the genetic make-up would never change.

15. Sexual Reproduction- brings together a new combination of genes. Introduces new combinations of genes every generation.

16. 2. In a population, more individuals are produced than the environment can support. They compete for food and shelter. (overproduction- struggle for survival).

17. 3. Some individuals have adaptive characteristics that enable them to survive and reproduce better than other individuals (survival of the fittest).

18. 4. An increasing number of individuals in succeeding generations have these adaptive characteristics (natural selection)

20. Evolution takes place through a set of processes that include: • mutation, • adaptation, • natural selection, • extinction.

21. When humans choose organisms with specific characteristics as breeding stock, they are performing the role of the environment • This is called “selective breeding” Example of selective breeding in plants: five vegetables derived from wild mustard

22. Selective breeding in Animals: Dog Breeding German shepherd Yorkshire terrier English springerspaniel Mini-dachshund Golden retriever Hundreds tothousands of yearsof breeding(artificial selection) Ancestral dog

23. Evidence of Evolution How do we know there has been changes?

24. The study of fossils provides strong evidence for evolution. Petrified Trees Hominid skulls

25. Younger Older Relative Dating Relative Dating

26. Fossilized organic matter in a leaf Ammonite casts

27. “Ice Man” Scorpion in amber

28. Homologous Structures provide evidence of evolution Human Cat Whale Bat

29. Vestigial Structures EX.: appendix in humans, whale pelvis, tiny snake pelvic and limb bones, and the eyes in cave-dwelling salamanders and fish that are completely blind.

30. Provide evidence that organisms evolved from a common ancestor

31. The central ideas of evolution are that life has a history. It has changed over time and that different species share common ancestors.