1. Concept Map Evolution of Life Section 17-2
Early Earth was hot; atmosphere contained poisonous gases.
Earth cooled and oceans condensed.
Simple organic molecules may have formed in the oceans..
Small sequences of RNA may have formed and replicated.
First prokaryotes may have formed when RNA or DNA was enclosed in microspheres.
Later prokaryotes were photosynthetic and produced oxygen.
An oxygenated atmosphere capped by the ozone layer protected Earth.
First eukaryotes may have been communities of prokaryotes.
Multicellular eukaryotes evolved.
Sexual reproduction increased genetic variability, hastening evolution.

2. Figure 17-8 Miller-Urey Experiment
Section 17-2
Mixture of gases simulating atmospheres of early Earth
Spark simulating lightning storms
Cold water cools chamber, causing droplets to form
Condensation chamber
Water vapor
Liquid containing amino acids and other organic compounds

3. Figure 17-12 Endosymbiotic Theory
Section 17-2
Chloroplast
Plants and plantlike protists
Aerobic bacteria
Ancient Prokaryotes
Nuclear envelope evolving
Photosynthetic bacteria
Mitochondrion
Primitive Photosynthetic Eukaryote
Animals, fungi, and non-plantlike protists
Ancient Anaerobic Prokaryote
Primitive Aerobic Eukaryote

4. Geologic Time Scale with Key Events
Section 17-3
Era
Period
Time
(millions of years ago)
Key Events
Cenozoic
Mesozoic
Paleozoic
Precambrian
Time
Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
1.8–present
65–1.8
145–65
208–145
245–208
290–245
363–290
410–363
440–410
505–440
544–505
650–544
Glaciations; mammals increased; humans
Mammals diversified; grasses
Aquatic reptiles diversified; flowering plants; mass extinction
Dinosaurs diversified; birds
Dinosaurs; small mammals; cone-bearing plants
Reptiles diversified; seed plants; mass extinction
Reptiles; winged insects diversified; coal swamps
Fishes diversified; land vertebrates (primitive amphibians)
Land plants; land animals (arthropods)
Aquatic arthropods; mollusks; vertebrates (jawless fishes)
Marine invertebrates diversified; most animal phyla evolved
Anaerobic, then photosynthetic prokaryotes; eukaryotes, then multicellular life

5. Patterns of Evolution
Section 17-4
Macroevolution refers to large-scale evolutionary patterns and processes that occur over long periods of time. Includes extinction, adaptive radiation, convergent evolution, coevolution, punctuated equilibrium, and changes in developmental genes.

6. Extinction
More than 99% of all species that have every lived are now extinct.
Occur because species compete for resources and environments change (natural selection).
Mass extinctions wiped out entire ecosytems. Food webs collapsed and disrupted energy flow through the biosphere.
Most mass extinctions caused by several factors.
Large volcanoes erupting, continents moving, sea levels changing.
Leads to burst of evolution as species fill niches.

7. Adaptive Radiation
A single species or a small group of species has evolved, through natural selection and other processes, into diverse forms that live in different ways.
Darwin’s finches – more that a dozen species evolved from a single species.
Dinosaurs – ruled earth for about 150 million years.
Mammals – disappearance of dinosaurs lead to adaptive radiation of mammals.

8. Convergent Evolution
Process in which unrelated organisms come to resemble one another.
Groups of different organisms, such as mammals and dinosaurs, undergo adaptive radiation in different places or at different times but in ecologically similar environments. Face similar environmental pressures. Natural selection molds different body structures into modified forms (arms and legs into wings and flippers).
Analogous structures – look and function similarly but are made up of parts that do not share a common evolutionary history.

9. Coevolution
Organisms that are closely connected to one another by ecological interactions evolve together.
Flowers and pollinators
As evolutionary change in one organism may also be followed by a corresponding change in another organism.
Analogous structures – look and function similarly but are made up of parts that do not share a common evolutionary history.

10. Punctuated Equilibrium
Fossil records show that some organisms evolved gradually over time.
Others are in equilibrium – have changed little over time.
Long, stable periods are interrupted by brief periods of more rapid change – punctuated equilibrium. May occur when
a small population becomes isolated from the main part of the population or a small group migrates to a new environment.
a mass extinction occurs.
Organisms evolve rapidly to fill available niches.

11. Flowchart Section 17-4 Species that are Unrelated Related form in
under
under in in
Inter-relationshiops
Similar environments
Intense environmental pressure
Small populations
Different environments
can undergo
can undergo
can undergo
can undergo
can undergo
Coevolution
Convergent evolution
Extinction
Punctuated equilibrium
Adaptive radiation

12. Click a hyperlink to choose a video. Geologic Time Evolution of Cells
Videos
Click a hyperlink to choose a video.
Geologic Time
Evolution of Cells
Video Contents

13. Go Online Career links on fossil preparators Interactive test
For links on the fossil record, go to and enter the Web Code as follows: cbn-5171.
For links on eukaryotic cells, go to and enter the Web Code as follows: cbn-5172.
For links on extinction, go to and enter the Web Code as follows: cbn-5174.
Internet