Name: ___________________________
Per.: _______
Date: _____
Mass Extinctions on Earth over Time
Objective: Identify the timing of mass extinctions and research their causes.
Procedure: Use the data below to create line graph that illustrates the number of
families (groups of related organisms) on Earth over the past 525 million years.
Data
Millions of years ago
Number of Families (Related groups of species)
(x axis)
(y axis)
525
100
510
180
500
160
475
300
450
410
440
405
435
325
415
425
410
430
400
425
380
440
370
440
350
367
333
395
325
435
240
375
235
210
220
380
205
240
100
550
80
600
65
530
0
760
Name: ___________________________
Per.: _______
Date: _____
Mass Extinctions on Earth over Time
Objective:
 Identify the timing of mass extinctions and the causes of mass
extinctions.
Part 1: Identifying Mass Extinctions on a Graph
Directions: IDENTIFY and LABEL each mass extinction you see on your
graph.

Write the approximate time of each mass extinction on the graph where
it occurs.

Write the name of each mass extinction on the graph (“PermianTriassic” for example). You will determine the names through your
research.
Part 2: Internet Research
BBC's NATURE: The Big 5 Extinctions: http://www.bbc.co.uk/nature/extinction_events
Use this article to research the possible causes of specific mass extinctions.
BBC's NATURE: Mass Extinction Causes http://www.bbc.co.uk/nature/extinction_causes
Use this article to research HOW methane release, flood basalts, climate change, and impact events cause
extinctions.
Select ONE of the mass extinctions you identified to research. Your
research should include the following details:
1. Name of extinction and when it happened
2. What percentage of species went extinct (Overall, Marine, and/or
Terrestrial).
3. Identify the types of species that were most negatively affected.
4. What was the cause or causes of each mass extinction? Provide
details on how these causes actually caused species to go
extinct (Ex: How do flood basalts cause extinctions?)

Summarize your research in paragraph form (Topic sentence,
details, closing sentence). Summaries should incorporate
researched facts and details.
Part 3: Sixth Mass Extinction?
Today many biologists think we are going through ANOTHER extinction event
that HUMANS are causing. Research the possibility of a human-caused mass
extinction.
Links:
Video
PBS 6th Mass Extinction (9 min)
https://www.youtube.com/watch?v=z9gHuAwxwAs
Egghead’s: Are We Facing a Sixth Mass Extinction? (3 mins)
https://www.youtube.com/watch?v=INWqAABweTg
Articles
BBC’s: A Looming Mass Extinction Caused by Humans
http://www.bbc.com/future/story/20121101-a-looming-mass-extinction
Discovery News: World’s Sixth Mass Extinction May Be Under Way
http://news.discovery.com/earth/weather-extreme-events/mass-extinction-humans-animals110303.htm
In paragraph form address the following questions.
1.
How can humans be causing a possible mass extinction? What human
activities are causing extinctions? Explain.
2. What organisms are on the losing end of this hypothesized mass
extinction?
3. Even if humans are not the cause of a mass extinction, do you think
another mass extinction is possible? Probable? Why or why not? Defend
your answer with reasons.
Mass Extinction Activity
Graph
 Mass extinctions labeled with estimated time
Points
5
and name.
Research Paragraphs (2 Total)
 1 on Historical Mass Extinction
 1 on the current Sixth Mass Extinction




Total
30
Paragraphs have topic sentence and have been proofread for
grammar and sense.
Paragraphs have accurate facts.
Paragraphs include all required details.
Paragraphs incorporate explanations or summaries in your own
words.
35 points