1. Tracing Evolutionary History
Chapter 15
Tracing Evolutionary History

2. Day 1: Do Now: 295, HW Define words from 15. 1-15. 6, Notes 15. 7-15
Day 1: Do Now: 295, HW Define words from , Notes , Video on Early Earth Formation (united streaming) Day 2: Do Now: 15.6 Explain how bird feathers are a exaptation, Notes: , Simple classification lab Day 3: Caminalcules Lab Day 4 and 5: Biodiversity Lab Day 6 Test on chapter

3. Do Now: Read pg 294-295 Green Book
What evidence did experts use to conclude that birds were dinosaurs with feathers?
What piece of evidence was found recently that disagrees with this hypothesis?
HW: Read and define the following words
Macroevolution, Geologic time scale, Radiometric dating, continental drift, Pangea, plate techtonics, exaptation

4. Are Birds Really Dinosaurs with Feathers?
For decades, evolutionary biologists debated whether birds evolved from dinosaurs
Fossil Archaeopteryx supported this view
Conflicting view posited birds evolving from a very different reptile group
Bird-dinosaur link was supported by cladistics and corroborated in the 1990s by fossil evidence
Debate continues on how birds learned to fly

7. MACROEVOLUTION AND EARTH'S HISTORY
15.1 The fossil record chronicles macroevolution
Macroevolution is the main event in the evolutionary history of life on Earth
Documented in the fossil record
The geologic record is based on the sequence of fossils
Earth's history divided into three eons
Within the most recent eon, eras and periods marked by mass or lesser extinctions

8. Animation: The Geologic Record
Some major events in the history of life
Precambrian period: oldest known fossils- prokaryotes from 3.5 billion years ago
Paleozoic era: lineages that gave rise to modern life forms
Mesozoic era: age of reptiles, including dinosaurs
Cenozoic era: Explosive evolution of mammals, birds, and flowering plants
Animation: The Geologic Record

10. 15.2 The actual ages of rocks and fossils mark geologic time
Radiometric dating can gauge the actual ages of fossils and the rocks in which they are found
Based on the decay time of radioactive isotopes relative to other isotopes
Carbon-14 for relatively young fossils
Isotopes with longer half-lives for older fossils

11. 15.3 Continental drift has played a major role in macroevolution
Continental drift is the slow, incessant movement of Earth's crustal plates on the hot mantle
World geography changes constantly

12. LE 15-03a Eurasian Plate North American Plate Arabian Plate Indian
Pacific
Plate
African
Plate
Split
developing
South
American
Plate
Nazca
Plate
Australian
Plate
Antarctic Plate
Edge of one plate being pushed over edge of
neighboring plate (zones of violent geologic events)

13. Continental movements have greatly influenced the distribution of organisms around the world
Formation of Pangaea 250 million years ago altered habitats and triggered extinctions
Breakup of Pangea beginning 180 million years ago created a number of separate evolutionary arenas
Explains the geographical distribution of diverse life forms
Examples: marsupials, lungfishes

14. LE 15-03b 65 135 251 Cenozoic Millions of years ago Mesozoic Paleozoic
Cenozoic
North America
Eurasia 65
Africa
South
America
India
Australia
Antarctica
Laurasia
135
Millions of years ago
Mesozoic
Gondwana
251
Pangaea
Paleozoic

16. LE 15-03d North America Asia Europe Africa South America Australia=
Living lungfishes =
Fossilized lungfishes

17. Video: Galápagos Islands Overview
CONNECTION
15.4 Tectonic trauma imperils local life
Plate tectonics are the forces involved in movements of Earth's crustal plates
The geologic processes that result include volcanoes and earthquakes
Can create devastation or opportunities for organisms
The boundaries of plates are hot spots of such geologic activity
Video: Galápagos Islands Overview

18. LE 15-04a
San Andreas Fault
North
American
Plate
San Francisco
Santa Cruz
Pacific
Plate
Los Angeles
California

20. 15.5 Mass extinctions were followed by diversification of life-forms
Extinctions occur all the time, but extinction rates have not been steady
Over the last 600 million years, at least six periods of mass extinctions have occurred, including
Permian extinction (250 million years ago); claimed 96% of aquatic life
Cretaceous extinction (65 million years ago); eliminated dinosaurs

21. Cause of mass extinctions is unclear
Permian extinction occurred at a time of enormous volcanic explosions
Cretaceous extinction may have been caused by an asteroid
Mass extinctions have been followed by an explosive increase in diversity
Provide surviving organisms with new environmental opportunities
Example: rise of mammals after extinction of dinosaurs

22. LE 15-05 North America Chicxulub crater Yucatan Peninsula Yucatan
Yucatan
Peninsula

23. 15.6 Key adaptations may enable species to proliferate after mass extinctions
Exaptation is a structure that evolved in one context and later was adapted for another function
Example: birds had feathers and light bones before the benefit of flight

24. 15.7 Genes that control development are important in evolution
"Evo-devo" combines evolutionary and developmental biology
Studies how slight genetic changes can be magnified into significant phenotypic changes
Many striking evolutionary transformations are the result of a change in the rate or timing of developmental changes
Paedamorphosis: retention in adult of features that were juvenile in its ancestors

25. LE 14-12b
Chimpanzee fetus
Chimpanzee adult
Human fetus
Human adult

26. Important in human evolution
Large skull and long childhood provide humans with more space for brain and more opportunity to learn from adults
Juvenile physical traits may make adults more caring and protective
Example: "evolution" of Mickey Mouse

27. 15.8 Evolutionary trends do not mean that evolution is goal directed
Evolutionary trends reflect the unequal speciation or unequal survival of species on a branching evolutionary tree
Example: lineages of horses that died out
Evolutionary trends do not imply an intrinsic drive toward a goal
If environmental conditions change, an apparent trend may cease or reverse

28. Hippidion and other genera
LE 14-13
RECENT
Equus
Hippidion and other genera
PLEISTOCENE
Nannippus
Pliohippus
Hipparion
Neohipparion
PLIOCENE
Sinohippus
Megahippus
Callippus
Archaeohippus
Merychippus
MIOCENE
Anchitherium
Hypohippus
Parahippus
Miohippus
OLIGOCENE
Mesohippus
Paleotherium
Epihippus
Propalaeotherium
Pachynolophus
Orohippus
EOCENE
Grazers
Hyracotherium
Browsers

29. 15.9 Phylogenetic trees strive to represent evolutionary history - Easy with living organisms, hard with extinct - Still a hypothesis

30. 15.10 Systematists classify organisms by phylogeny
A phylogenetic tree is a hypothetical hierarchy of evolutionary relationships
A binomial gives each species a two-part name
Genus (a group of related species)
Species within the genus
Genera are grouped into progressively more inclusive categories (taxa)
Family, order, class, phylum, kingdom, domain

31. LE 15-07a Felis catus Species Felis Genus Felidae Family Carnivora
Order
Mammalia
Class
Chordata
Phylum
Animalia
Kingdom
Eukarya
Domain

32. LE 15-07b Genus Felis Mephitis Lutra Canis Family Felidae Mustelidae
catus
Mephitis
mephitis
Lutra
lutra
Canis
familiaris
Canis
lupus
Species
(domestic
cat)
(striped skunk)
(European
otter)
(domestic dog)
(wolf)
Genus
Felis
Mephitis
Lutra
Canis
Family
Felidae
Mustelidae
Canidae
Order
Carnivora

33. PHYLOGENY AND SYSTEMATICS
15.11 Homology indicates common ancestry, but analogy does not
Phylogeny
Traced partly from the fossil record
Inferred from morphological and molecular homologies among living organisms
Not all likenesses are inherited from a common ancestor
Analogy: similarity due to convergent evolution
Species from different branches resemble each other if they live in similar environments

35. 15.12 Molecular biology is a powerful tool in systematics
Molecular systematics uses DNA and RNA to compare relatedness
The closer the nucleic acid sequences between two organisms, the more likely they are to share a common ancestor
Humans are more closely related to fungi than to plants

36. LE 15-09a Polar bear Asiatic black bear American black bear Sun bear
Sloth
bear
Spectacled
bear
Giant
panda
Lesser
panda
Brown bear
Raccoon
Pleistocene
Pliocene 10
Miocene 15 20
Millions of years ago
Ursidae 25 30
Procyonidae
Oligocene 35
Common ancestral
carnivorans 40

37. Types and indications
Proteins that change more rapidly are useful among closely related species
DNA (more direct)
Mt DNA changes faster, better for closely related organisms
rRNA changes slowly, relationships in early branches
Some sections of DNA changes at a constant rate
Changes are proportional to time
Genes can be used to calculate a molecular clock

38. LE 15-09c
Human
Chimpanzee
Gorilla
Orangutan
Common ancestor

39. 15.13 Cladograms are diagrams based on shared characters among species
Cladistics is concerned with the order of branching in phylogenetic lineages
Each branch (clade) on a cladogram represents an ancestral species and all its descendants
Each clade consists of taxa that are monophyletic (from a "single tribe")

40. All the taxa on a clade share one or more homologous features
Shared derived characters: New traits unique to each lineage
Shared primitive characters: Traits present in the ancestral groups
Comparison of ingroup and outgroup is important
Ingroup: Group of taxa being analyzed
Outgroup: Closely related to the ingroup but not a member of it

41. Parsimony seeks the simplest explanation of observed data
The simplest hypothesis of relationships creates the most likely phylogenetic tree

42. LE 15-08b
Lizards
Snakes
Crocodiles
Birds
Common reptilian ancestor

43. 15.14 Arranging life into kingdoms is a work in progress
Five-kingdom system (now six)
All prokaryotes are in kingdom Monera (Now two Archeabacteria and Eubacteria)
Eukaryotes are grouped into four kingdoms: Protista, Plantae, Fungi, Animalia
Molecular studies have found flaws in this system

44. Animation: Classification Schemes
The domain system
Prokaryotes are in two domains: Bacteria and Archaea
All eukaryotes are in domain Eukarya
All classification systems are human constructions, not facts of nature
Will always be refined by new data
Animation: Classification Schemes

45. Three Domains (Superkingdoms) Of Living Organisms I
Three Domains (Superkingdoms) Of Living Organisms I. Bacteria (19): Most of the Known Prokaryotes Kingdom (s): Not Available at This Time Division (Phylum) Proteobacteria: N-Fixing Bacteria Division (Phylum) Cyanobacteria: Blue-Green Bacteria Division (Phylum) Eubacteria: True Gram Posive Bacteria Division (Phylum) Spirochetes: Spiral Bacteria Division (Phylum) Chlamydiae: Intracellular Parasites II. Archaea (16): Prokaryotes of Extreme Environments Kingdom Crenarchaeota: Thermophiles Kingdom Euryarchaeota: Methanogens & Halophiles Kingdom Korarchaeota: Some Hot Springs Microbes III. Eukarya (35): Eukaryotic Cells Kingdom Protista (Protoctista) Kingdom Fungi Kingdom Plantae Kingdom Animalia

46. Monera Protista Plantae Fungi Animalia Earliest organisms Prokaryotes
LE 15-10a
Monera
Protista
Plantae
Fungi
Animalia
Earliest
organisms
Prokaryotes
Eukaryotes

47. LE 15-un311-1
Lizards
Birds
Mammals