1. Evolution Chapters 15/16

2. Intro Video https://youtu.be/FpfAZaVhx3k?list =PLISBHwlJXpn2bmLjfiShKcIHpBP cov24Ohttps://youtu.be/FpfAZaVhx3k?list =PLISBHwlJXpn2bmLjfiShKcIHpBP cov24O https://youtu.be/FpfAZaVhx3k?list =PLISBHwlJXpn2bmLjfiShKcIHpBP cov24Ohttps://youtu.be/FpfAZaVhx3k?list =PLISBHwlJXpn2bmLjfiShKcIHpBP cov24O

3. Evolution A change over time A process by which modern organisms have descended from ancient organisms Theory- a broad, well tested explanation that unifies a broad range of observations A change over time A process by which modern organisms have descended from ancient organisms Theory- a broad, well tested explanation that unifies a broad range of observations

4. Earth’s History More than 4 Billion years old Fossils- preserved remains of ancient organisms Many modern life forms appear to be modifications of fossil forms More than 4 Billion years old Fossils- preserved remains of ancient organisms Many modern life forms appear to be modifications of fossil forms

5. Theories of Evolution Three Scientists Lamarck Malthus Darwin Three Scientists Lamarck Malthus Darwin

6. Lamarck French Scientist Proposed that acquired traits were passed on to offspring

7. Acquired Trait- one that is not determined by genes, instead arises over time by experience or behavior –Example- developing large muscles Disproved by current knowledge of genetics Acquired Trait- one that is not determined by genes, instead arises over time by experience or behavior –Example- developing large muscles Disproved by current knowledge of genetics

8. Malthus Stated that if the human population continued to grow unchecked, sooner or later there would be insufficient living space and food for everyone

9. Charles Darwin British Scientist Sailed on ship HMS Beagle on trip to explore S. America Was the Naturalist on board, collecting plant and animal samples British Scientist Sailed on ship HMS Beagle on trip to explore S. America Was the Naturalist on board, collecting plant and animal samples

10. Darwin’s Work While on the Beagle, Darwin collected and recorded information about all types of living species Back in Britain he analyzed his observation and published The Origin of Species While on the Beagle, Darwin collected and recorded information about all types of living species Back in Britain he analyzed his observation and published The Origin of Species

11. Darwin’s Theories Descent with Modification- newer forms of life are modified descendents of older species Modification by Natural Selection- states how evolution is occurring Descent with Modification- newer forms of life are modified descendents of older species Modification by Natural Selection- states how evolution is occurring

12. Theory Part 2 Concepts Natural Selection- organisms best suited to their environment will reproduce more successfully Adapt- a change in a population in response to the environment Natural Selection- organisms best suited to their environment will reproduce more successfully Adapt- a change in a population in response to the environment

13. Fitness- an individual’s genetic contribution to the next generation –High fitness= more offspring Survival of the fittest- competition for food and living space will only allow for those best suited to environment to reproduce Fitness- an individual’s genetic contribution to the next generation –High fitness= more offspring Survival of the fittest- competition for food and living space will only allow for those best suited to environment to reproduce

14. Evidence of Evolution Homologous Features Analogous Features Vestigial Structures Conserved Genes Similarities in Embryos Macromolecules Homologous Features Analogous Features Vestigial Structures Conserved Genes Similarities in Embryos Macromolecules

15. Homologous Features Similar features that have slightly different mature forms but originated from a common ancestor –Example- forearm of mammals Similar features that have slightly different mature forms but originated from a common ancestor –Example- forearm of mammals

16. Analogous Feature Have same function, but have different development –Example: Wings on bird and insect

17. Vestigial Structures Organ that serves no current purpose in organism, but is believed to have one in ancestor –Examples: Tailbone in humans Appendix in humans Pelvic bones in whales Organ that serves no current purpose in organism, but is believed to have one in ancestor –Examples: Tailbone in humans Appendix in humans Pelvic bones in whales

18. Conserved Genes A gene that remains unchanged within DNA, but is turned off and not used –Example: hind legs in whales

19. Similar Embryos During early fetal development, vertebrates all appear the same

20. Macromolecules All have DNA as basis Similar amino acid sequence that make up proteins –More similarities the closer related the two organisms are

21. Patterns of Evolution Co-evolution Convergent Divergent Co-evolution Convergent Divergent

22. Coevolution Changes in two or more species in close association with each other –Example- plant and animal pollinators Changes in two or more species in close association with each other –Example- plant and animal pollinators

23. Convergent Occurs when the environment selects for similar phenotype, even though ancestry is very different –Example- body shape of dolphins and sharks

24. Divergent Two related species becoming different from one another Two Types –Adaptive –Artificial Two related species becoming different from one another Two Types –Adaptive –Artificial

25. Divergent Adaptive- change is in response to habitat –Example: Galapagos finches Divergent Adaptive- change is in response to habitat –Example: Galapagos finches Divergent Artificial- other interference speeds up differences (breeding) –Example: Dog breeding

26. Genetic Equilibrium Population Genetics- looking at evolution from a genetic point of view Population- members of a species that live in the same area and make up a breeding group Population Genetics- looking at evolution from a genetic point of view Population- members of a species that live in the same area and make up a breeding group

27. In normal circumstances the percentages of a particular trait remain constant –Equilibrium In normal circumstances the percentages of a particular trait remain constant –Equilibrium

28. Disruption of Equilibrium Mutation Genetic Drift Migration Non-random Mating Natural Selection Mutation Genetic Drift Migration Non-random Mating Natural Selection

29. Mutation- any change to DNA –Can affect the protein made which can affect the individual and their offspring Mutation- any change to DNA –Can affect the protein made which can affect the individual and their offspring Genetic Drift- allele frequencies (%) change due to chance or random events –Example- Natural disasters

30. Migration- net movement in or out of a population –Immigration- moving into a population –Emigration- movement out of a population Migration- net movement in or out of a population –Immigration- moving into a population –Emigration- movement out of a population Migration creates gene flow Gene Flow- movement of genes from one population to another

31. Non-random Mating- mating in small populations –Leads to higher occurrences of disorders –Example- Amish Non-random Mating- mating in small populations –Leads to higher occurrences of disorders –Example- Amish

32. Natural Selection Traits being selected for or against Three Types –Stabilization –Directional –Disruptive Traits being selected for or against Three Types –Stabilization –Directional –Disruptive

33. Stabilization Selection Type of natural selection in which the average form is being selected for

34. Directional Selection Type of natural selection in which one extreme is being selected for, creating movement in one direction

35. Disruptive Selection Type of natural selection in which the average is being selected against and both extremes are being selected for

36. Formation of Species Speciation- process of forming new species Morphology- internal and external structure and appearance –Scientists use this as basis for classifying species Speciation- process of forming new species Morphology- internal and external structure and appearance –Scientists use this as basis for classifying species

37. Biological Species Concept- A species is a population that can interbreed, but not breed with other groups

38. Isolating Mechanisms Mechanisms that can cause new species to form Two Types –Geographic –Reproductive

39. Geographic Isolation- having a physical barrier between groups –Example: river, canyon, mountain

40. Reproductive Isolation- barrier to successful breeding Examples: different mating calls, different mating seasons Reproductive Isolation- barrier to successful breeding Examples: different mating calls, different mating seasons

41. Rates of Speciation Gradual- slow change over time –Lots of intermediates in fossil record Punctuated- sudden shift in fossil record –Could be caused by natural disaster or other sudden change to environment Gradual- slow change over time –Lots of intermediates in fossil record Punctuated- sudden shift in fossil record –Could be caused by natural disaster or other sudden change to environment