1. Evidence of Evolution
This PowerPoint was revised Jan 1, 2010 for Unique
TEACHER NOTES
This PowerPoint was revised June 8, 2004

2. GENETIC CHANGE IN A POPULATION THROUGH TIME.
EVOLUTION IS
GENETIC CHANGE IN A POPULATION THROUGH TIME.
Population Dynamics
POPULATIONS IN ECOSYSTEMS

3. EVIDENCES OF EVOLUTION
Population Dynamics
POPULATIONS IN ECOSYSTEMS

4. Charles Darwin
On his journey around the world, Darwin found evidence of gradual change (evolution).
Darwin cited evidences he found in fossil records, geographic distribution and homologous structures.

5. Evidences of Evolution
Today most evidences for evolution are grouped into five main categories:
Biochemical
Fossil Record
Comparative Anatomy
Biogeography
Observable Events

6. FOSSIL RECORD Paleontology
Fossil – remains or traces of an organism that lived long ago
Remains: ex. bone, tooth, or shell
Traces: ex. burrow, footprint, or imprint
Photos by cbray

7. FOSSIL RECORD Most fossils are found in layered sedimentary rock
Oldest fossils are on the lowest layer
Layers diagram by cbray

8. FOSSIL RECORD Comparing fossils from different layers shows:
Life on Earth has changed
Increased number of life forms

9. BIOCHEMICAL THE GENETIC CODE
Triplets of DNA nitrogen-base sequences that code for specific amino acids
The amino acid triplet is the same in almost all organisms.
Genetic code table by cbray

10. BIOCHEMICAL
The similarity of triplet DNA codes making-up amino acids shows:
A probable common ancestor for all life on Earth

11. BIOCHEMICAL “Universal” GENETIC CODE Similar genes
Over the ages, the genetic code
has passed unchanged (or nearly so) from parent to offspring.

12. Number of differences from human hemoglobin
BIOCHEMICAL
AMINO ACID SEQUENCING
The amino acid sequence in a particular protein is compared between organisms. 8
125 45 27
Amino acid differences designed by cbray (with PPT clip art) 67 1
Number of differences from human hemoglobin

13. Amino Acid Difference in Hemoglobin Compared with Human
BIOCHEMICAL
Comparing amino acid sequence shows:
Closeness of relationship
A probable common ancestor
Amino Acid Sequencing is probably the STRONGEST evidence for relationships among organisms.
Amino Acid Difference in Hemoglobin Compared with Human
Species
Difference
Gorilla 1
Rhesus Monkey 8
Mouse 27
Chicken 45
Frog 67
Lamprey
125
Amino acid differences chart by lpriddy
Human hemoglobin has 146 amino acids

14. Number of Amino Acid Differences
Amino Acid Difference in Hemoglobin Compared with Human
BIOCHEMICAL
Species
Difference
Gorilla 1
Monkey 8
Mouse 27
Chicken 45
Frog 67
Lamprey
125
CLADOGRAM: diagram that shows the evolutionary relationship among a group of organisms. B A C D
Number of Amino Acid Differences
150
100 50 40 20 30 10
Where would the common ancestor be?
What organism belongs at each branch? E F
Amino acid differences chart by lpriddy G
Common ancestor

15. COMPARATIVE ANATOMY HOMOLOGOUS STRUCTURES
structures with similar structure but different function
(ex: turtle, alligator, bird, mammal)
Turtle
Alligator
Bird
Mammal

16. COMPARATIVE ANATOMY Homologous structures show Similar genes
Descent from a common ancestor
Turtle
Alligator
Bird
Mammal
Ancient lobe-finned fish

17. COMPARATIVE ANATOMY VESTIGIAL STRUCTURES
organs so reduced in size that they are nonfunctioning remnants of similar organs in other species
ex: human tailbone, appendix, whale pelvis
Whale pelvis diagram by cbray

18. COMPARATIVE ANATOMY Vestigial structures show:
an organism’s evolutionary past
a common ancestor with species that have similar structures that are still functioning

19. COMPARATIVE ANATOMY Analogous Structures
Unrelated species have evolved to have similar adaptations

20. COMPARATIVE ANATOMY EMBRYOLOGY
Embryos of different species may appear similar in early stages of development
Embryo drawings by cbray
ex: vertebrate development

21. COMPARATIVE ANATOMY Comparison of similarities in embryos can show:
Relationship to a common ancestor
Embryo drawings by cbray

22. BIOGEOGRAPHY GEOGRAPHIC DISTRIBUTION OF ORGANISMS
organisms living widely apart (even different continents) may be similar because they share a common ancestor
Beaver
Muskrat
Beaver and Muskrat
Coypu
Capybara
Coypu and Capybara
Shows common ancestor

23. OBSERVABLE EVENTS
Some changes in species have been observed and studied:
Peter & Rosemary Grant’s Study of Beak Size Shift in Darwin’s Finches
H. Kettlewell’s Study of Peppered Moth Color Shifts

24. OBSERVABLE EVENTS
Observable events show that evolution is an ongoing process
Peter & Rosemary Grant’s Study of Beak Size Shift in Darwin’s Finches
H. Kettlewell’s Study of Peppered Moth Color Shifts

25. Works Cited
Miller, Kenneth and Levine, Joseph. (2004). Biology. Prentice Hall.