1. Evidence for Evolution
Chapter 18
BioH Ch 18

2. Petrified tree sap = “amber” (Basis for Jurassic Park movies)
Fossils are not always “bone-like”
Petrified tree sap = “amber”
(Basis for Jurassic Park movies)

3. Let’s examine five important cases.
Fossil Evidence
In 2004, scientists digging in the Canadian Arctic unearthed fossils of a half-fish, half-amphibian that all but confirmed paleontologists' theories about how land-dwelling tetrapods–four-limbed animals, including us–evolved from fish.
It is a classic example of a transitional form, one that bridges a so-called evolutionary gap between different types of animal.
Let’s examine five important cases.

4. Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)

5. Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)

6. Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)

7. Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)

8. Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)

9. Fossilization
Just an example – no need to memorize, but interesting (SKIP for 2013 Evolution test)
“Lucy”

10. Stratification
The lower in the stratification that a fossil is found, the older it is assumed to be. Good for comparisons only – not always a good determinant of age.

11. Evidence of evolution can lead to the formation of a timeline of development of life on Earth…
Fossil records
Relative Dating
Radioactive dating
Geologic Time Table

12. Click on picture to go to the web page. Zoom in & out to see details
Click on picture to go to the web page. Zoom in & out to see details. When do humans appear?

13. ERA’s correspond with major extinction events
Current Era & Period – modern man (Cenozoic, Quaternary)

14. Comparative Morphology
Common ancestors?
Comparative Morphology
18.2 – Similarities in bone structure have led scientists to believe that there may have been a common ancestor
Morphological divergence
Homology

15. Morphological divergence
Organisms diverge in appearance due to environmental differences. Also – Darwin’s finches

16. Morphological Convergence
Organisms develop similar appearances due to environmental similarities.
Fish
Mammal
Bird

17. “Ontogeny recapitulates phylogeny”
18.3 Examining embryo development led scientists to believe that these organisms may have had similar ancestors. Do not memorize the sentence at the top!
Embryological Evidence

18. Comparative Biochemistry Evidence
DNA, RNA, proteins comparisons between species
18.4 – nucleic acid hybridization. Neutral vs. adaptive mutations can lead to predictable “molecular clock”

19. Systems of Classification
Based on SIMILARITIES
Visual
Location
Anatomical
Physiological
Genetic
???
Easiest to identify?
MOST important/ BEST relationships?
Other forms of classification? Which makes MOST sense? (SKIP for 2013 Evolution test)

20. Linnaeus’s System Hierarchy Seven levels - Taxons Kingdom Phylum Class
Order
Family
Genus
Species
(SKIP for 2013 Evolution test)

21. King Philip? King Philip Came Over For Good Soup Kingdom Phylum Class
Order
Family
Genus
Species
(SKIP for 2013 Evolution test)

22. Binomial Nomenclature
Genus and Species name
Polar bear – Ursus maritimus
Grizzly Bear – Ursus arctos
What are the reasons to use a binomial system?
Giant Panda – Ailuropoda melanoleuca

23. Old vs. Modern Systems
Derived characteristics rely on genetic/evolutionary information. Be able to construct a cladogram (see next slide)
Evolutionary classification (descent characteristics):
Segmented bodies
Jointed limbs
Exoskeleton that is shed
Derived characteristics = CLADOGRAM

24. Exercise
Be able to construct & read a cladogram.

25. Taxonomy Identifying, classifying species Classification schemes
Binomial system
Phylogeny
K-P-C-O-F-G-S
18.5 (SKIP for 2013 Evolution test)

26. Kingdoms
Archaebacteria – Ancient bacteria, unicellular, prokaryote. Found in extremely harsh environments.
Eubacteria - More modern bacteria, uniclelluar, prokaryote. “Common bacteria”
Protista – Eukaryote, unicelluar or multicellular. Autotroph or heterotroph. Pathogens and parasites.
Fungi – Multicellular, eukaryote. Heterotroph. Decomposers, pathogens, parasites.
Plantae - Multicellular, eukaryote. Autotrophs
Animalia - Multicellular, eukaryote. Heterotroph.
Summarize in table (SKIP for 2013 Evolution test)

27. Radiometric Dating
Radioactive decay
in everyday life
18.7 (skip 18.6)

30. A Changing Earth
18.6 – Pangea, continental drift, texctonics

31. Evidence of Change Life Fossil evidence Stratification
Radiometric dating
Geology
Sedimentary layers
Similar mineralization
Aging of mountain ranges

32. What’s in the future?