EVOLUTIONARY TIMELINE                                                                                                                     

Exercise. Understanding Earth’s Changes Over Time

Introduction
Comparing the magnitude of geologic time with spans of time in a person’s lifetime is difficult for many people. In this activity, you will use a long paper strip and a reasonable scale to represent virtually all of geologic time, including significant events in the development of life on earth as well as recent human events.

Materials and Equipment
The following materials will be needed by each group of two students:
• A paper strip, such as adding machine or cash register tape • A meter stick
• A calculator • Colored pencils • Evolutionary/Geologic Timeline

Directions
Use the materials described above to plot a model of earth’s changes over time. Be sure to perform the following tasks:
• Calculate a scale that can be used to display the events on the timeline (make sure your scale is used in a legend on the model); limit your scale to NO MORE than 16 meters long
• Have a title for your model;
• Use colored pencils to plot the events and use an icon of some sort to visually depict the events on your model (e.g., a lizard drawing to represent the rise of the reptiles) NOTE: you will diagram only some of the events----see Evolutionary/Geologic Timeline sheet below

EVOLUTIONARY/GEOLOGICAL TIMELINE
Time (Millions of years ago) Event
DO THESE ABOVE LINE_____
4600 Formation of the approximately homogeneous solid Earth by planetesimal accretion
4300 Atmospheric water is photodissociated by ultraviolet light to give oxygen atoms which are incorporated into an ozone layer and hydrogen molecules which escape into space
3800 The Earth's crust solidifies---formation of the oldest rocks found on Earth
3800 Condensation of atmospheric water into oceans
3500--2800 Prokaryotic cell organisms develop
3500--2800 Beginning of photosynthesis by blue-green algae which releases oxygen molecules into the atmosphere and steadily works to strengthen the ozone layer and change the Earth's chemically reducing atmosphere into a chemically oxidizing one
1500 Eukaryotic cell organisms develop
1500--600 Rise of multicellular organisms (Cambian explosion)
545 Cambrian explosion of hard-bodied organisms

DO EVERY OTHER OF THESE EVENTS BELOW LINE
500--450 Rise of the fish---first vertebrates
430 Waxy coated algae begin to live on land
420 Millipedes have evolved---first land animals
375 The Appalachian mountains are formed via a plate tectonic collision between North America, Africa, and Europe
375 Appearance of primitive sharks
350--300 Rise of the amphibians
350 Primitive insects have evolved
350 Primitive ferns evolve---first plants with roots
300--200 Rise of the reptiles
300 Winged insects have evolved
280 Beetles and weevils have evolved
250 Permian period mass extinction
230 Roaches and termites have evolved
225 Modern ferns have evolved
225 Bees have evolved
200 Pangaea starts to break apart
200 Primitive crocodiles have evolved
200 Appearance of mammals
145 Archaeopteryx walks the Earth
136 Primitive kangaroos have evolved
100 Primitive cranes have evolved
90 Modern sharks have evolved
65 The Chicxulub impact occurs
65 K-T Boundary---extinction of the dinosaurs and beginning of the reign of mammals
60 Rats, mice, and squirrels have evolved
60 Herons and storks have evolved
55 Rabbits and hares have evolved
50 Primitive monkeys have evolved
28 Koalas have evolved
20 Parrots and pigeons have evolved
20--12 The chimpanzee and hominid lines evolve
4 Development of hominid bipedalism
4--1 Australopithecus exist
3.5 The Australopithecus Lucy walks the Earth
2 Widespread use of stone tools
2--0.01 Most recent ice age
1.6--0.2 Homo erectus exist
1--0.5 Homo erectus tames fire
0.2--0.03 Homo sapiens neanderthalensis exist
0.05--0 Homo sapiens sapiens exist
0.04--0.012Homo sapiens sapiens enter Australia from southeastern Asia and North America from northeastern Asia
0.025--0.01 Most recent glaciation---an ice sheet covers much of the northern United States
0.017 Homo sapiens sapiens paint the Lascaux cave
0.01 First permanent homo sapiens sapiens settlements
0.01 Homo sapiens sapiens learn to use fire to cast copper and harden pottery
0.006 Writing is developed in Sumeria
0.0046 Oldest known Pine tree starts to grow

DO ALL BELOW LINE

Mount Vesuvius eruption destroys Pompeii, A.D. 79
First U.S. satellite orbited, 1958
First man on moon, 1969
The year you began high school.
Today.