1. Shaping Darwin’s Ideas Review Chapter 16 Sections 1, 2, and 3.

2. Evolution The process of change over time Darwin developed a theory of biological evolution that explains how organisms evolved over long periods of time through descent from common ancestors.

3. Darwin’s Adventures Darwin observed that: 1.Different, yet similar, animal species inhabited separated, but similar, habitats around the globe. 2.Different, yet related, animal species often occupied different habitats within a local area. 3.Some fossils of extinct animals were similar to living species.

4. Hutton and Lyell Concluded that Earth is extremely old and that the processes that changed Earth in the past are the same processes that operate in the present.

5. Hutton Concluded that Earth must be much older than a few thousand years. Deep time: our planet is so old that we cannot imagine that length of time.

6. Lyell Uniformitarianism: geological processes we see today must be the same ones from the past that shaped Earth Earth was much, much older than a few thousand years So, how old is Earth? About 4.5 billion years old!

7. Malthus Economist that noted humans were reproducing faster than dying If humans population grew unchecked, there wouldn’t be enough food or space for everyone. This would cause war, famine, disease, etc.

8. Malthus’ Graph

9. Chunk N Chew

10. Lamarck Organisms could change during their lifetimes by selectively using or not using various parts of their bodies. Individuals could pass these acquired traits on to their offspring, enabling species to change over time. Acquired Characteristics: traits changed by an individual organism during its lifetime Inheritance of Acquired Characteristics: traits changed during an individual’s lifetime can be passed on to offspring

11. Lamarck’s Giraffe

12. Artificial Selection Darwin studied farmers breeding plants and animals and selecting for specific traits that would increase their products In artificial selection, nature provides the variations, and humans select those they find useful.

13. Artificial Selection Darwin studied farmers breeding plants and animals and selecting for specific traits that would increase their products In artificial selection, nature provides the variations, and humans select those they find useful.

14. Variation and Adaptation Variation: different versions of something (traits) There is natural variation in the world some variants are better suited for the environment than others……Examples? Adaptation: an inherited characteristic that increases and an organism’s ability to survive and reproduce in its environment Examples?

15. Survival of the Fittest Fitness: how well an organisms can survive and reproduce in its environment. Well suited organisms that survive and reproduce are said to have a high fitness Not well suited organisms either die without reproducing or leave few offspring are said to have a low fitness NOTE: Survival is more than just staying alive. What else does it include

16. Natural Selection Natural Selection: the process by which organisms with variations most suited to their local environment survive and leave more offspring. Occurs in any situation in which there is: 1.A struggle for existence 2.Variation and adaptation 3.Survival of the fittest Turn and Talk: Examples

17. Common Descent – Descent with Modification “Tree thinking” All species – living and extinct – are descended from ancient common ancestors Deep time gave enough time for natural selection to act and create descent with modification

18. Common Descent – Descent with Modification

19. Evidence of Evolution Supporting Darwin’s Theory

20. Biogeography The study of where organisms live now and where they and their ancestors lived in the past. Patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors.

21. Biogeography Closely Related but Different: The Galapagos Islands – likely came from mainland population Distantly Related but Similar: Populations around the world have similar characteristics – likely because of similar environmental pressures

22. Fossils How old is Earth? 4.5 billion years old Indicated by radioactive dating Fossil Record There are many gaps Many recent discoveries fill in some of those gaps and help make connections to evolution EX: Dinosaurs to birds What is one of the most recent fossil discoveries? Wooly Mammoth Homo Naledi

23. Comparative Anatomy Homologous Structures: structures that are shared by related species and that have been inherited from a common ancestor Help determine how recent a species shared a common ancestor Analogous Structures: Body parts that carry a common function, but not structure THE KEY TO COMMON DESCENT IS SIMILAR STRUCTURE Vestigial Structures: Structures inherited by ancestors, but have lost much or all of their original function due to selection pressures

24. Comparative Anatomy

27. Embryology The same groups of embryonic cells develop in the same order and in similar patterns of development. Recall What Darwin Never Knew Switches Similar patterns of embryological development provide further evidence that organisms have descended form a common ancestor.

28. Molecular Biology The universal genetic code and homologous molecules provide evidence of common descent The genetic code is almost identical in all organisms. Can also have homologous proteins, genes Recall What Darwin Never Knew HOX genes

29. Natural Selection Today The Grants research of the Galapagos Island Finches The Grants Did the real life research that we did during our bird beak lab Data shows that variation within a species increases the likelihood of the species’ adapting to and surviving environmental change. Can you think of any natural selection that is happening today? Turn and Talk with a partner