Name: _________________________________________
Period: ________
History of Life Webquest –Chapters 4.1, 25
First Organic Molecules: http://www.windows2universe.org/earth/Life/miller_urey.html
The Miller-Urey Experiment
1. What was the purpose of their experiment?
2. What did they find in the liquid pool?
3. Their experiment lends support for what theory?
Miller-Urey Experiment Animation:
http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter26/animation_-_millerurey_experiment.html
1. The early atmosphere contained what gases?
2. On the diagram to the right, label the water reservoir, electrodes and
condenser.
3. Put a star where they added the gases present in the early Earth.
4. Why was the water heated?
5. What did the electric sparks mimic?
6. What did formaldehyde and hydrogen cyanide combine to form?
7. What did their experiments show? IMPORTANT!
How did Life Originate? http://evolution.berkeley.edu/evolibrary/article/side_0_0/origsoflife_01
1. How old is the Earth? __________________________ (you should know this!)
2. Evidence suggests that life first evolved around __________________________ (you should know this!)
3. Where do scientists believe life originated?
FYI: The first genetic material was most likely RNA, not DNA.
4. List the 5 steps that led to multicellular life.
Important Events in the History of Life: http://evolution.berkeley.edu/evolibrary/article/evo_13
Using the timeline put the date of each significant event.
Years
ago
Event
_________
Anatomically modern humans evolve. Seventy thousand years later, their descendents create cave
paintings — early expressions of consciousness.
__________
In Africa, an early hominid, affectionately named “Lucy” by scientists, lives. The ice ages begin, and
many large mammals go extinct.
__________
A massive asteroid hits the Yucatan Peninsula, and ammonites and non-avian dinosaurs go extinct.
Birds and mammals are among the survivors.
__________
As the continents drift toward their present positions, the earliest flowers evolve, and dinosaurs
dominate the landscape. In the sea, bony fish diversify.
__________ Dinosaurs and mammals evolve. Pangaea has begun to break apart.
_________
Over 90% of marine life and 70% of terrestrial life go extinct during the Earth’s largest mass extinction.
Ammonites are among the survivors.
__________
The supercontinent called Pangaea forms. Conifer-like forests, reptiles, and synapsids (the ancestors of
mammals) are common.
__________
Four-limbed vertebrates move onto the land as seed plants and large forests appear. The Earth’s oceans
support vast reef systems.
__________ Land plants evolve, drastically changing Earth’s landscape and creating new habitats.
__________ Arthropods move onto the land. Their descendants evolve into scorpions, spiders, mites, and millipedes.
__________
Fish-like vertebrates evolve. Invertebrates, such as trilobites, crinoids, brachiopids, and cephalopods,
are common in the oceans.
__________
Multi-cellular marine organisms are common. The diverse assortment of life includes bizarre-looking
animals like Wiwaxia.
__________ Unicellular life evolves. Photosynthetic bacteria begin to release oxygen into the atmosphere.
__________ Replicating molecules (the precursors of DNA) form.
__________ The Earth forms and is bombarded by meteorites and comets.
*Using a highlighter, highlight these important events: Oxygen in atmosphere, which led to Plants evolve, which
allowed 4-limbed vertebrates on land
Endosymbiosis: http://evolution.berkeley.edu/evolibrary/article/endosymbiosis_01
1. What did Kwang Jeon discover when researching Amoeba infected by bacteria?
2. What is endosymbiosis?
3. How does the meaning of the root words “endo-“ and “-symbiosis” help you understand the meaning of
endosymbiosis?
4. How does endosymbiosis play a role in the evolution of prokaryotes to eukaryotes, and how are mitochondria
important to this evolution?
5. What is the evidence scientists have to support endosymbiosis and the evolution of prokaryotes to eukaryotes?
6. What is another cell organelle that is thought to have originated through endosymbiosis?
7. Could you find free-living mitochondrion today? Why or why not?
8. What are some questions scientists still have about endosymbiosis?
Mass Extinctions: http://www.bbc.co.uk/nature/extinction_events
Click on each of the major extinctions to fill-in the graphic organizer.
Major
Extinction
Time
Organisms affected/
% life lost
Cause of extinction
OrdovicianSilurian
Late Devonian
Permian
*Largest Mass
Extinction in
History
Triassic Jurassic
CretaceousTertiary
Using your textbook (pg. 523-524), answer this question: how have mass extinctions affected evolution (think about the
(obvious) negatives AND positives)?
Fossil Record: http://www.ucmp.berkeley.edu/education/explorations/tours/fossil/index.html (select student level 2)
1. Name five kinds of trace fossils.
2. Find the walnut. How did it become a fossil?
3. What happened to the mammoth?
4. Why are the mouse and the jellyfish being compared?
5. Why is it difficult for an organism living in the rainforest to become a fossil?
6. What are two reasons why many organisms never become part of the fossil record?
7. What are two ways that geologic processes can destroy a fossil?
8. Why isn't igneous rock a good place to look for fossils?
9. Find the map of Montana. What are two things to keep in mind when you are looking for a fossil like T. rex?
What do the colors and letters represent?
10. You are a paleontologist at a fossil dig site in the Gobi Desert. You find a site filled with many fossilized leaves,
teeth, bones, eggs and even footprints from a variety of creatures. BUT you find no trace of insects. One possible
explanation is that no insects lived in the Gobi at that time. What is another possible explanation for the lack of
insects?