1. Evolution Part I:

2. Charles Darwin is known as the Father of Evolution. What we know now seems like common sense but in Darwin’s day, it wasn’t. So…..How did Darwin come up with his new and radical ideas that eventually led to the (controversial) Theory of Evolution?

3. After studying at Cambridge, Charles was recommended for a surveying trip on the HMS Beagle. He sailed around the world on the Beagle for 5 years, working as a naturalist.

4. On the voyage, Darwin noticed that everywhere he went, the animals and plants differed vastly. Yet, there were similarities Patterns in the species suggested that the species had changed over time and had given rise to new and different species.

5. The Galapagos Islands lie 500 miles west of Ecuador in the Pacific Ocean, directly on the equator. Many of Darwin’s conclusions were based on observations of wildlife in the Galapagos Islands. “Galapagos” means turtle.

6. Were the animals and plants created to match their environment? Then, why didn’t the Galapagos finches look like the birds of the African continent, since the environments of both the Galapagos and Africa were similar.

7. Darwin guessed that some of the birds from South America migrated to the Galapagos. Once on the islands, the birds must have changed over the years because Once on the islands, the birds must have changed over the years because each island was different from the others….landscape and flora.

8. Darwin called this… or (change in species over time) Darwin concluded: Each species had descended, with changes, from other species over time. Descent With Modifications

9. …or Survival of the Fittest. The mechanism by which evolution takes place. Five basic components:

10. 1. All species have genetic variation. Nature has to have some variety in order to choose. Look around you…are you all the same?

11. 2. Organisms produce more offspring than can survive. Many that survive do not produce offspring. The female green sea turtle lays a clutch of about 110 eggs. She may lay several clutches. It is likely that less than 1% of the hatchlings will ever reach sexual maturity.

13. 3. Since more organisms are produced than can survive, there is competition (struggle for existence). Competition exists WITHIN and AMONG species. food Within and Among Species for And Within a Species for water mates shelterspace

15. Short-term natural disasters can have large impacts on competion. (drought, fires, floods, snowstorms, hurricanes, and tornadoes) Long-term changes in the environment also affect survival. (ice ages, biome shifts, global warming etc)

16. 4. Survival of the fittest Some organisms are more suited to their environment as a result of variations in the species. the ability of an individual to survive and reproduce in its specific environment. Fitness is a result of adaptations. Fitness: the ability of an individual to survive and reproduce in its specific environment. Fitness is a result of adaptations. He who spreads the most genes wins! 1st Individuals that are fit to their environment survive and leave more offspring than those who aren’t.

17. 5. Descent with modification: Living species today are descended with modifications from common ancestral species that lived in the past. Over time, genes for less favored characteristics will be eliminated from the gene pool. Example: giraffes and their increasingly longer necks. Characteristics of fit individuals increase in a population over time.

18. Natural Selection: Survival of the Fittest the variation has to already exist. An adaptation is any inherited characteristic (a genetic variation) that can increase an organism’s chance of survival. If the environment changes. the variation may give an advantage to survive environmental change. An organism does not change because of the need or desire to survive. The organism is either born with the variation that enables it to survive or it dies.

19. Darwin published his theory in the book November 24, 1859 And that is why Darwin is the father of Evolution

20. Camouflage (Cryptic coloration)

21. Mullerian Mimicry –untasty imitates untasty ….both benefit by making sure their predators gets the point. Monarch and Viceroy Butterfly

22. Batesian Mimicry – palatable (tasty) mimics unpalatable (untasty) Coral vs. King Snakes: Red on yellow, kill a fellow, red on black friend of Jack

23. Warning Coloration (Aposematic coloration)

24. Disruptive Coloration

25. Counter Shading

26. Eye spots

27. Things to remember: a. Populations evolve, not individuals. b. Natural selection is the mechanism of evolution. c. Evolution occurs by chance (NOT GOAL ORIENTED). d. Organisms are born with adaptations, they can’t adapt because they need or want to

28. Part II Speciation Causes of evolution Rates of evolution

29. –An organism that has the potential to interbreed in nature and produce viable, fertile offspring that looks like their parents. Speciation is the creation of a new species

30. results from which include produced by which result in Reproductive Isolation Isolating mechanisms Behavioral isolationTemporal isolation Geographic isolation Behavioral differencesDifferent mating times Physical separation Independently evolving populations Formation of new species Occurs when 2 pop. are capable of interbreeding but have different courtship rituals or other reproductive strategies that involve behavior Two or more species reproduce at different times Two pop. Are separated by geographic barriers such as rivers, mountains, or bodies of water Speciation results from

31. A reproductive barrier is any factor that prevents two species from producing fertile hybrids, thus contributing to reproductive isolation. Habitat/Geographical Isolation Temporal Isolation Behavioral Isolation Mechanical Isolation Gametic Isolation

33. Causes of Evolution 1.Mutations - random changes in genetic material at the level of the DNA nucleotides or entire chromosomes 2.Natural Selection - most important cause of evolution; measured in terms of an organism's fitness – The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals…the more fit, the more they contribute.

34. Modes of Selection (types of natural selection) a. Stabilizing Selection - average phenotypes have a higher fitness over the extreme phenotypes b. Directional Selection - phenotype at one extreme has a higher fitness over the average and the other extreme c. Disruptive Selection - both extreme phenotypes have a higher fitness than the intermediate phenotypes

35. In this case, darker mice are favored because they live among dark rocks and a darker fur color conceals Them from predators. These mice have colonized a patchy habitat made up of light and dark rocks, with the result that mice of an intermediate color are at a disadvantage. If the environment consists of rocks of an intermediate color, both light and dark mice will be selected against. Phenotypes (fur color) Original population Original population Evolved population Frequency of individuals Modes of Selection Directional Disruptive Stabilizing

36. Causes of Evolution 3. Mating Preferences - Organisms usually do not choose their mates at random, thus the selection process can cause evolution 4. Gene Flow - Transfer of genes between different populations of organisms. This situation leads to increased similarity between the two populations (Tends to reduce differences between populations over time) 5. Genetic Drift (Founder Effect & Bottleneck) - Situation that results in changes to a population's gene pool caused by random events, not natural selection. This situation can have drastic effects on small populations of individuals. Common on islands.

37. Gene Flow

38. Genetic Drift

39. Founder Effect

40. Bottleneck Effect

42. Part III: Types of Evolution Extinction

43. 1. Divergent Evolution - Multiple species of organisms descended from the same common ancestor at some point in the past. –Method of evolution accounting for the presence of homologous structures. –Adaptive Radiation. Ex. Darwin’s finches

45. 2. Convergent Evolution - Because certain adaptations are more advantageous in different environments, unrelated organisms that live in similar environments will have similar features that perform similar functions. –Method of evolution accounting for the presence of analogous structures. – Ex. Dolphins and shark

47. 3. Coevolution –Organisms that are closely connected evolve together. –Method of evolution accounting for specialists. Ex. Monarch butterfly and milkweed plants Insects and flowers

49. As the environment changes, organisms must have variations (adaptations) that will determine whether they can survive with the changes or they can’t and they die. If an entire species cannot adapt, that species will then become extinct. No More, Finished, Bye- Bye!

50. There have been at least 5 MASS extinctions during Earth’s history where a huge % of the living species were destroyed

51. At least one of these mass extinctions has been attributed to meteor impact and it’s consequences.

52. It is estimated that 1/5 or more of the world’s species will become extinct if the rainforests are destroyed. Many scientists say that the earth is currently experiencing a mass extinction crisis.

53. Part IV: Evidence of Evolution

54. 1. Fossil Evidence: –Paleontology - Study of Fossils Fossil - preserved evidence of past life –Fossil record: shows organisms that are no longer living and how they changed over time. a. Relative dating –Which rock layer is the fossil found…If you know the age of one, the rest of them are about the same age. –Index fossils: wide range, short time period b. Radioactive dating –Measuring radioactive isotope vs. stable atom content »Carbon 14

56. MORPHOLOGICAL HOMOLOGY (similarities) 2. HOMOLOGOUS STRUCTURES –Structures that are similar because they are derived from a common ancestral structure

60. A structure that serves the same function in two taxa, but is NOT derived from a common ancestral structure is said to be an ANALOGOUS STRUCTURE

62. 3. Embryology (ontogenic) Homology As organisms develop, they go through many stages that are similar to other organisms. –The longer two organisms share developmental stages, the more closely related they are to each other.

65. 4. Molecular Homology -The comparison of different proteins (amino acids) can show how closely related species are to each other. -The fewer differences in the genetic make-up, the closer related they are.

66. Hybridization of DNA can also show evolutionary relationships.

67. 5. Vestigial Structures Structures that have marginal, if any, use to the organisms in which they occur. –Reduced in size. –Derived from an earlier ancestor that did use/need this structure.

69. 6. Biogeography The study of the geographical distribution of organisms. –Species that are related to each other tend to live near each other. (fossils of ancestors are present too) –As geography changes, populations are separated or combined with new populations. Continent movement (collide and separate), rivers, mountains, lakes, etc. separate populations

72. Evolutionary biologists can use all evidence to create a cladogram. A chart that shows the development of particular traits and the evolutionary relationships between different species. Cladograms