Download Biological Time Line

Biological Time Line
How long is a million years? How long is a billion years? The vast amount of time that has passed since the origin of
Earth is difficult for most people to imagine. However, when events in time are considered in relationship to one another,
the concept of time is easier to grasp. It also becomes easier to understand how the changes in the Earth’s environment
or one the evolution of one group of creatures affects the evolution of another species. Changes in the environment can
cause the extinction of large group of creatures. When a large group of creatures goes extinct in a short period of time,
called a mass extinction, allows the rapid evolution of a new group of surviving species. These events aren’t easily
noticed until all the events are organized in chronological order.
Using the list of organisms and events provided, list these significant events in Earth’s history and evolution in order, from
oldest to youngest. Then, using this list answer the following questions to help explain how and why some species
evolved when they did.
Events in Earth’s History
1. Earth’s formation - 4.6 billion years ago
2. First Homo sapiens- 200,000 years ago
3. First reptiles- 360 million years ago
4. Single eukaryotic cells (cells with nucleus) evolve- 2.2 billion years ago
5. First dinosaurs- 248 million years ago
6. First Birds evolve- 110 million years ago
7. Formation of Pangaea (Supergiant land mass) - 225 million years ago
8. Oxygen gas builds up in the atmosphere- 2.7 billion years ago
9. First animals ( jellyfish, sponges, aquatic worms)- 700 million years ago
10. Modern mammals evolve- 60 million years ago
11. Ozone layer surrounds Earth, protection from UV radiation from the sun- (600 million years ago
12. Oldest known fossils (Bacteria) – 3.5 billion years ago
13. Plants evolve onto land- 438 million years ago
14. First oceans (liquid water on Earth’s surface)- 4.4 billion years ago
15. Hominids (humanlike primates) walk the Earth- 5.8 million years ago
16. First flowers- 144 million years ago
17. First insects- 416 million years ago
18. Evolution of vertebrates/ fish - 500 million years ago
19. Breaking apart of Pangaea - 200 million years ago
20. Dinosaurs go extinct (50% plant and animal species go
extinct)- 65 million years ago
21. First mammals evolve – 251 million years ago
22. First Amphibians- 408 million years ago
23. Permian Mass Extinction (95% marine species, 70%
terrestrial creatures go extinct)- 248 Million years ago
24. First Primates take to the trees- 55 million
Place the events in order from oldest to most recent. All event years should be written out in numeric form.
Event Year
Event Title
1
Earth’s Formation
4,600,000,000 = 4.6 Billion years
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
1.
2.
Place the following creatures in order from when they first appeared on the planet, from oldest to youngest: reptiles,
eukaryotic cells, birds, fish, mammals, dinosaurs, amphibians, bacteria
a.
e.
b.
f.
c.
g.
d.
h.
What was the first living organism on the planet?
3.
For how many years were bacteria the only type of life on the planet?
4.
What creatures evolved from bacteria?
5.
For how many years was there no life on the planet?
6.
How long were there dinosaurs on the planet?
7.
When did Homo sapiens (modern humans) evolve?
8.
Someone suggests that the first reptiles would eat the fruits that came from flowers. Is this possible? Why or why
not?
9.
Many TV shows and cartoons show ancient humans being attacked by or hunting dinosaurs. According to the events
of Earth’s history, is this possible? Explain why or why not.
10.
The fossil record suggests that the first forms of life evolved in the oceans. What evidence do you see that shows life
evolved in the oceans?
11.
For a new group of creatures to take over an area, there usually has to be a mass extinction of the existing creatures
that are already in that area. Before mammals were able to take over the land, what group of creatures had to go
extinct first?
12.
Which types of creatures first began to produce oxygen and release it into the air?
13.
Why was it important for plants to evolve onto land first, before insects and animals could evolve onto land?
14.
Why is mass extinction, when many different species die off in a short period of time, important for evolution?
15.
Which types of creatures benefitted from the Permian mass extinction? What creatures were able to evolve from the
loss of so many species on Earth?
16.
Birds evolved from dinosaur ancestors. Why didn’t birds go extinct when the dinosaurs went extinct?
17.
Cockroaches first evolved about 200 million years ago, and have had very little changes since then. Why have
cockroaches not evolved further in 200 million years?
18.
When the supercontinent Pangaea started to break apart into the smaller continents we have today, the fossil record
shows there was a mass extinction. Why would a mass extinction have resulted from the breakup of Pangaea?
19.
Did life evolve onto land before or after the Ozone layer formed? Why?
Scientists have found the fossil remains of several different groups of organisms. The diagram below represents the
number and age of the fossils the scientists found. The width of each shaded area in the diagram below indicates the
relative number of fossils found.
20.
Using the chart above, which group went extinct?
21.
Which group evolved first?
22.
What order did the groups evolve?
23.
Which group appears to have the greatest fitness?
24.
10 million years ago, the environment begins to change do to the growth of a new mountain range. Which group
begins to lose its fitness due to this change?
25.
If all of the groups are related to each other through history,
26.
Did the disappearance of Group 2 seem to have an impact on any of the other groups? Which one?
27.
Which two groups seem to be competing with each other for resources? Explain your answer?
28.
One of these groups is a producer. Which one is the producer and why do you think so.