1. Evolution Mincer/Scully

2. Evolution Evolution-The process by which species change over time, or become extinct. Species-All the organisms that can interbreed and produce fertile offspring, and look roughly alike. Extinction-When all members of a species have died and that species no longer exists.

3. Charles Darwin Lived in England When he was young, he took a voyage on the H.M.S. Beagle They sailed into the Pacific Ocean, to the Galapagos, and Darwin discovered several new species, including species of finches that were found nowhere else. This led him to think about why the finches on the Galapagos would be different than those in England.

4. Darwin Basically, Darwin said that living populations change over time because of changes in their environment. Certain individuals are ‘selected’ to breed because they are better adapted to the change in the environment. He called this process, ‘natural selection’

5. Evolution-Some terms Adaptation-A trait that an organism has which helps it to survive its environment. Natural Selection- The natural change in environment which will determine which traits are useful and which are not; those traits will be passed on to succeeding generations.

6. Peppered Moth The peppered moth comes in two colors: white and black The white color is favored by natural selection, because the bark of the trees that the moth rests on is white. This makes it hard to be spotted by birds.

7. Pepper Moth However, when the factories in England started up, the bark of the trees often was covered in soot. This made the bark of the trees black. Scientists started seeing the moth population change from almost all white to almost all black.

8. Peppered Moth If this had happened long enough, the moth would have become a new species that was all black.

9. Evidence-Observations Fossils-Fossils are the petrified bones of animals and plants that lived thousands to millions of year ago, e.g. the dinosaurs Fossils take a really really long time to form. There have to be exactly the right conditions when the animal dies

10. Evidence-Observation Vestigial organs-The appendix is an organ which is not used for anything in humans, but is used in many other mammals, like rabbits to help in the digestion of food.

11. Evidence of Evolution Homologous Body Structures- Body structures of different species which look very similar, if not the same.

12. Evidence DNA! Scientists have compared the DNA of many organisms, and organisms that have similar structures often have very similar DNA. Humans and Chimpanzees have 98% the same DNA

13. How does Evolution Work? Genetics! Each species has a natural variation, because of different alleles. When something in the environment changes, some traits may provide an advantage, those traits, and therefore genes, are passed on to the next generation.

14. So… The genes which code for traits which help the organism survive are going to be passed on. Those that are not helpful are not going to be passed on, but eliminated from the gene pool. Over many generations, a new species can form.

15. Hardy-Weinberg Principle States that gene frequencies will remain constant unless something causes them to change There are five main conditions that need to remain stable for gene frequencies to remain stable: 1. Random mating must occur 2. Population must be large 3. No immigration or emigration 4. No mutations 5. No environmental changes

16. Speciation Behavioral isolation: Occurs when two populations are capable of reproduction, but their behaviors force them to not to mate with each other. Geographic Isolation: Two populations are separated by geographic barriers, like mountains or rivers, preventing interbreeding. Temporal Isolation: When two or more species reproduce at different times.

17. Behavioral Isolation

18. Geographic Isolation

19. Temporal Isolation

20. History of Life on Earth The pattern seems to be from simpler forms to more complex forms Several mass extinctions of large numbers of species have caused rapid evolution to occur, –eg. 65 million years ago, and the Permian Mass Extinction

21. Patterns Extinction- 99% of all species who ever lived are now extinct Adaptive Radiation- One species (Or a small grouping of species) evolves into many different diverse forms Convergent Evolution- When two species evolve along similar lines, look similar, but evolved from very different ancestors E.g. bird and bats

22. Patterns of Evolution Coevolution- When two species, or groups of species, evolve together in an ecosystem. E.g. flowers and insects Punctuated Equilibrium- Long stable periods of no speciation, with short rapid changes. Changes in developmental genes-Hox genes (Master control genes) change slightly (mutation), changing how other genes are expressed.

23. Adaptive Radiation Co evolution Convergent Evolution Extinction