1. S&T: 3 pg. 310 give examples of types of evidence that Darwin gathered to develop the theory of evolution;
Structural similarities among organisms.
Geographic distribution of organisms.
The embryological similarities among organisms.
The pattern of organism groupings.
The direct observation of evolutionary changes in the laboratory and in the wild.
The molecular similarities among organisms- were found after Darwin (more to come ).
7.Transitional species found in fossil record.-bonus

2. Evidence for Evolution

4. Key Idea Evidence for evolution comes from many sources. Fossils
Vestigial structures
Biogeography
Homologous structures
Embryology
DNA/protein sequences

5. Fossils Fossils provide evidence of evolution.
Fossils in older layers are more primitive than those in the upper layers.
Extinct Fossils resemble modern animals. This shows a common ancestry.

7. Dating Fossils
Relative dating estimates the time during which an organism lived.
It compares the placement of fossils in layers of rock.
Scientists infer the order in which species existed.

8. Transitional species found in fossil record – fish-amphibian (Tiktaalik)
375 million years old
Discovered in Canada in 2004

9. Transitional fossil: bird/reptile Archaeopteryx 150 million yrs old
Transitional fossil: bird/reptile Archaeopteryx 150 million yrs old. 7 specimens found

10. Fossil Evidence for Whale Evolution
Whale Video

11. 2. Vestigial Structures
Vestigial structures are remnants of organs or structures that had a function in an early ancestor.
Examples include ostrich wings, human appendix, and wisdom teeth, whale and snake pelvis/hind legs.

13. Pythons have tiny femurs (leg bone)

14. 3. Biogeography
Biogeography: the study of past and present distribution of species.
The study of geography provides evidence of evolution.
island species most closely resemble nearest mainland species
populations can show variation from one island to another

15. 4. Homologous Structures
Homologous structures- Similar anatomical features that originated in a shared ancestor.
Homologous structures are similar in structure but may be different in function.

17. Homologous Structures vs. Analogous Structures
Analogous structures have a similar function.
Analogous structures are not evidence of a common ancestor.
Human hand
Bat wing
Mole foot
Fly wing

18. Analogous Structures look similar on the outside same function
different structure & development on the inside
different origin
no evolutionary relationship
Solving a similar problem with a similar solution

19. Homologies: at the cellular level
Review from IS 1: What cellular structures are shared by all eukaryotic organisms?

20. 5. Embryology
Embryology- studying the early stages of development of an organism (inside the womb or inside the egg)

21. all vertebrate embryos have a “gill pouch” at one stage of development

23. Hox genes control body development in many organisms
Hox genes control body development in many organisms. They help control head to tail organization.

24. 6. DNA/Protein Sequences
Two closely-related organisms will have similar DNA, RNA, and protein (amino acid) sequences.
This also gives evidence of a common ancestor.

25. Comparing DNA & protein structure
everyone uses the same genetic code!
DNA 10 20 30 40 50 60 70 80 90
100
110
120
Lamprey
Frog
Bird
Dog
Macaque
Human 32 8 45 67
125
compare common genes
compare common proteins
number of amino acids different from human hemoglobin

26. DNA (cont)
DNA code itself is a homology that links all life on Earth to a common ancestor.
In some cases, if we were to transfer genetic material from the cell of one living thing to the cell of another, the recipient would follow the new instructions as if they were its own.
Useful in genetic engineering

27. GFP traditionally refers to the protein first isolated from a gene found in the jellyfish Aequorea victoria which glows in the dark.
This gene can be transferred to other organisms which will express this same trait

28. GloFish, the first genetically modified animal to be sold as a pet

29. Building “family” trees - Phylogenies
Closely related species are branches on the tree — coming from a common ancestor

31. Cladograms
diagram that depicts evolutionary relationships among groups.
based on PHYLOGENY, which is the study of evolutionary relationships.
Uses traits/characteristics that are common between organisms to organize them

33. You try: Match each point on the cladogram with the trait.
1. ______ Wings 2. ______ 6 Legs 3. ___ Segmented Body 4. ___ Double set of wings 5. ____ Jumping Legs 6. __ Crushing mouthparts 7. ____ Legs 8. ______ Curly Antennae

34. Phylogenetic trees Very similar to a cladogram
Tends to use genetic information and physical traits to construct
Root of the tree represents the ancestral lineage, and the tips of the branches represent the descendants of that ancestor.
As you move from the root to the tips, you are moving forward in time.

35. Speciation Species: a group of organisms that can interbreed in nature
Speciation: When two groups of organisms can no longer interbreed – they have become too different through evolution

36. When a lineage splits (speciation – forming a new species), it is represented as branching on a phylogeny. When a speciation event occurs, a single ancestral lineage gives rise to two or more daughter lineages.

37. Phylogenies trace patterns of shared ancestry between lineages
Phylogenies trace patterns of shared ancestry between lineages. Each lineage has a part of its history that is unique to it alone and parts that are shared with other lineages.

38. Each lineage also has ancestors that are unique to that lineage and ancestors that are shared with other lineages — common ancestors
Nodes represent common ancestors