1. Evolution
To see where we might be going, we must understand where we have been
Robert Tamarkin, 1993

2. Definition? Theory supported by evidence
Biological evolution concerns changes in living organisms during the history of life on earth.
Sharing of common ancestors
Darwin term: descent with modification

3. Branched Tree of Life
with a common
ancestor

4. Evidence of Evolution

5. Formation of the Earth
4.6 billion years old (dated from radiometric dating)
Complex: but woven out of 30ish main molecules – oxygen, hydrogen, carbon, nitrogen, Sulphur and phosphorus. (evidence #1)- present in early Earth- amino acids, RNA, DNA, Phosphorus, ATP

6. 1. Earth is Old: Fossils
Fossils: the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.

7. Generally older fossils are lower in the strata
Changes begin from simple to more complex
First Life Form – simple cells – fossil evidence 3.4 billion years ago
Generally older fossils are lower in the strata

8. Fossil Record Supports Evolution
Millions of fossils have been discovered
Fossil record shows changes of organisms through time from simple to more complex.
Documents the order of appearance of groups and types of organisms
Transitional Species show transitions from fish to tetrapods (fish to salamanders, salamanders to reptiles), dinosaurs to birds, proto-horses to horses , apes to human, synapsid to mammals.
Document major crises in Earth’s history and the recovery from events.

9. From Land to Water Tiktaalik
- transition between fish and tetrapods (four-legged)
-marks the appearance of limbs in fish –
- lived about 12 million years before the fist tetrapod- 363 million years old
Has gills, scales, no neck (like fish)
But – head is crocodile-like and strong hind limbs

10. From Land to Air – Archaeopteryx
Transition between bird and dinosaur
Bird Like features- feathers – tail feathers, evidence of flight
Dinosaur like features – sharp teeth, long bony tail, claws.

11. Oxygen Environment An increase in oxygen levels
Shown by red beds – iron “rusts” or turns red in the presence of oxygen
Luckily- happened slowly 2.7 to 2.0 bya
What type of organism was responsible for an increase in oxygen?

12. Radiometric Dating

13. Radiometric Dating
*Fossils show relative dating by comparing data in the rock strata – relationship to each other in the layers.
*Radiometric Dating ability to use absolute dating - done by comparing proportions of radioactive isotopes in the sample.
* Radiometric Elements are unstable (called parents) and they decay into different elements (daughter elements). Uranium to lead.
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14. Earth’s oldest crustal rocks – 4.03 billion years old.
Oldest metamorphosed sediment – zircon crystals found in Canada billion years old.

15. Radiometric Dating Supports Evolution
many naturally-occurring elements are radioactive and they break down, or decay, at known predictable rates.
isotope pairs are useful in dating the Earth such as rubidium/strontium, thorium/lead, potassium/argon, argon/argon, or uranium/lead, all of which have very long half-lives, ranging from 0.7 to 48.6 billion years.
Subtle differences in the relative proportions of the two isotopes can give good dates for rocks of any age.
Dates are often cross-tested using different isotope pairs.
Results from different techniques, often measured in rival labs, continually confirm each other.
Repeatable results

16. Natural Selection

17. Charles Darwin
Not exactly a star student, but he revolutionized the scientific view of the natural world with his Theory of Natural Selection
Traveled on the Beagle where his journey began in for a 5 year voyage
The Beagle traveled from Europe to the Galapagos Islands then to Australia around the Cape of Good Hope and back to Europe

18. Observations aboard the Beagle
Species vary globally
a. Two similar species live in different areas of the world
Species vary locally
a. Differences among tortoises in the Galapagos islands
Species vary overtime
Fossils of extinct animals looked similar to living animals

19. Natural Selection
Natural Selection: Organisms best suited to their environment survive and are able to produce offspring
Fitness-How well an organism can survive
Adaptation- Any heritable characteristic that increases an organisms ability to survive

20. Conditions Necessary for Natural Selection
Overpopulation- individuals in a population have a capacity to produce more offspring than the environment can support – leads to completion and a….
Struggle for existence
Variations – size, form, speed, camouflage, strength, horns, etc. -
Those best suited (fitness of traits) to the environment will survive and pass along their characteristics to their offspring.

22. Challenge
Describe evolution through natural selection in any species using terms from last slide – pick an adaptation

23. Directional Selection
Favoring one phenotype over others –
Examples
Darker-colored Peppered Moths in England and the Industrial Revolution
mouse population- brown mice on the brown forest floor.
Antibiotic resistance in bacteria and the use of antibiotics
Pesticide resistance in insects

25. Antibiotic Resistance
Antibiotic-Resistant Mycobacterium tuberculosis (TB)
Methicillin-Resistant Staphylococcus aureus (MRSA)
Vancomycin-Resistant Enterococci
(VRE)
Neisseria gonorrhoeae (Gonorrhea)
Clostridium difficile.
Gram-negative Bacteria.

26. Allele Frequency Changes
Peppered Moths During the
Industrial Revolution in
England
Dark Color is Dominant
Show a change over time in
three generations following
darkening of the trees

27. Directional
Selection –
depends on the
Rainfall
Seed Size increases during drought- Favors larger beaks

28. Stabilizing
Stabilizing – intermediate phenotypes selected because of a higher fitness *Examples – Human birth weight Plant height

29. Robins-
typically
lay
Four
eggs

31. Disruptive Selection
Extreme phenotypes are selected for by the environment
Example: African Finches – Large and small beaked birds have a higher survival rate than intermediate (environmental force – food availability –large seeds and small seeds)

33. Think about a situation
that might result in
Disruptive selection –
what type of
environment

34. Artificial Selection

35. Artificial Selection
Breeding of organisms (plants, animals, bacteria, etc.) to produce desirable traits.
Manipulated by humans
Examples:
Dogs for specific purpose- herding, hunting, pets, etc.
Fruit and veggies- improved tastes, resistance to pests, etc.
Roses – most beautiful
Fruit Trees- ability to survive in northern climates

37. Comparing anatomy
Homologous Structure: structures that are shared by related species and that have been inherited from a common ancestor

40. Table Buddy Colaboration
Research for 5 minutes examples of homologous structures – list in your notes
Come up with a reason why homologous structures support the theory of evolution.- explain in your notes.

41. Analogous Structures
When the function is common but the structure is different and example of this is the wing of a bird and the wing of a butterfly.

43. Vestigial Structures
inherited from ancestors but have lost much or all of their original function due to different selection pressures acting on the descendent
“left-overs”

45. The Process of Speciation
Species – population-members can interbreed and produce fertile offspring
speciation-formation of new species

49. Green algae evolution to land plant draw a picture and explain process
Table Buddy Collaboration
Green algae evolution to land plant draw a picture and explain process

51. Molecular Evidence of Evolution

53. Other Supports
All organism are cellular – membranes filled with water – genetic material, proteins, lipids, carbs, salts, etc.
Most organisms use sugar for fuel in s similar process
-proteins as building blocks and messengers- same amino acids to make them

54. Only three differences in plants and animal cells

55. Amino Acid Differences in Cytochrome c (CR)
Organism
Number of amino acid differences
Human
Chimpanzee
Rhesus monkey 1
Rabbit 9
Pig 10
Dog
Horse 12
Moth 24
Yeast 38

57. DNA Similarities

58. Collaboration – One Minute Summary 
Discuss with your table buddy what you would like to summarize as evidence of evolution covered in this unit – must include examples, all evidence presented. I will have you summarize in a 30 second to one minute summary -

59. Descent with Modification
A shared character is one that two lineages have in common, and a derived character:  character the sets the group
Examples of derived characters
Amniotic egg, lungs, vertebral
Columns, etc.