1. Unit B Chapter1 History of Life on Earth

2. Geological Evolution
The Earth’s surface is always changing and evolving.
What is that word we use to describe that the Earth is always changing?

4. Technological Evolution
Technology is always evolving and changing over time.
How have cell phones changed in the last ten years, 5 years, or even 2 years?
Technology is always evolving or changing, just like life.

7. Biological Evolution Life on the planet is always in a state of change
Fossils
Fossil evidence helps to support this
How do you think fossil evidence helps to support that species change over time?

10. Video of Evolution of Whales

11. Evidence for change in life
Mass extinctions:
Huge numbers of organisms go extinct at around the same time period
Many theories to why
New species always develop afterwards
Dinosaurs died out, leaving room for hairy mammals to adapt to the cold of the ice age

13. Mass Extinctions Cretaceous extinction
65 million years ago again 90% of life died out
Scientists think meteor hit somewhere in Mexico, turn to pg. B15 in book.

15. Evidence to support change in life
Evolution-theory that species change over time
Traits passed from one generation to the next
Slowly can change over time

16. Early Ideas Jean-Baptiste de Lamarck
First to say species can adapt during their life and pass traits onto their offspring
Giraffes neck was his evidence
Each generation was reaching to higher leaves and thus pass that on to babies
- He had no real evidence to support his ideas

18. Charles Darwin
Took a 5 year voyage around the world to develop his theory of
Natural Selection: members of a species best suited to an environment reproduce more at a higher rate than other members of a species.
This leads to changes over time
Most of his evidence taken from turtles and finches on islands

19. Natural Selection through adaptation example
You and I are running from a bear. If you run faster than me, who is the bear going to catch? Who will be able to produce more fast runners?
You were able to adapt faster then me. Your natural born speed enabled you to produce more offspring with your similar speed.

20. Darwin's Evidence
He visited the Galapagos Islands and saw the same type of turtles and finches (type of birds) who developed on different islands.
The turtles and finches adapted through natural selection.
This supported his theory of evolution.

21. Different Islands had different climates
Finches
Adapted with the size of their beaks depending on their food source.

22. Each bird developed on a different island

23. Speciation on different islands

25. Turtles adapted by their body structure

26. These are turtles found on different islands

27. Artificial Selection When humans selectively breed animals and plants.
This is true of some dog and plant species

28. Artificial evolution of peppers and dogs is an a example

29. Let’s Practice Figuring out natural selection of some finches and turtles

30. 4 main driving forces of evolution by natural selection
Overproduction
Variation
Adaptation
Selection

31. Overproduction
If an animal produces enough offspring some will survive
Can you even think of things that ONLY have the ability to produce ONLY 1 offspring? NO
Salmon
Lay several thousand eggs, only a few hundred will survive the disease and predators in the streams
Only a few dozen will make it long enough to breed

32. Overproduction of Pinecones

33. Variation Natural differences that help things to survive
Predators-ability to catch their meals vs. Prey- ability to elude the predators
Most of the time these are mutations
Curved tail in a salmon allows it to swim faster

34. Different variations in colors of shellfish

36. Adaptation An inherited trait that gives an organism an advantage
The curved tail allows the salmon to swim faster and a bear can’t catch it.

37. Same species of fish with different mouths to eat different things.

38. Selection Those animals born with a selective advantage survive longer
Those salmon with tails that allow it to swim faster, live longer, will have more babies just like them.

39. Video of 4 driving forces.

40. Review: Ask your partner the questions. BUT SWITCH EACH TIME
Review: Ask your partner the questions. BUT SWITCH EACH TIME. Record their responses
What do you know about overproduction and how it helps evolution?
What could you predict about adaptation of animals leads to evolution?
What is the relationship between variation and selection?
What is an example of adaptation?

41. Whole picture of biological evolution
Overproduction + Variation + Adaptation+ Selection= Natural Selection driving Evolution.

42. Speciation
Evolution of a new species from an existing one

43. What causes it?
Usually physical isolation from each other and their ability to adapt to a new location
Again think of the Galapagos Islands turtles and finches

44. Separated by mountains

46. Separated by a canyon

47. Evidence to support evolution
Fossils
Biological Structure
Genetics

48. Fossil Evidence Supports Evolution
Comparing fossils over time shows that there is a connection. The geologic time scale helps to show this

49. Elephant fossil timeline leads to one original ancestor

50. Dog fossils and structures lead back to one original species

51. Biological Structures
Comparing today’s animals and plants to those in the fossil record help to provide evidence
Vestigial Organs-are physical structures that were fully developed and functioning in an earlier group of organisms but are reduced and unused in later species.

52. Similar arm (wing) structure=similar ancestor

53. Vestigial organ: leg bones in whales

55. Vestigial Organ: Appendix in humans

56. Vestigial Organs: Wisdom teeth humans

57. Vestigial Organs: Wings of flightless birds

58. Evidence of hind legs on dolphins

59. Genetic Evidence
Scientists can now examine the DNA of organisms and have also notices similarities in animals from the past and today.
Same “stuff” in different animals=common ancestor

60. DNA comparisons

61. Write a paragraph at least 7 sentences long describing how fossils, biological evidence, and genetics support the theory of evolution. Be sure to talk about vestigial organs