Biodiversity over Time (Deep Time!) Name ________________ Hr ___
The x axis needs to be numbered from 550 Millions of Years Ago (M.a.) to the present (0) in
intervals of 50 million years. The y axis must be numbered from 0 to 6 Thousands of genera (plural form of
genus-which are subdivided into species), in intervals of 0.5.
1) Make a line graph with the data points below. Use a ruler to connect each point as you go. (0 ma is done)
2) Put a star ( * ) on the top of the data points that are starred in the table. (a star/dot)
These represent the 5 mass extinction events.
3) Extend a vertical line down from the data points to the X axis for every large dip in the line.
4) Referring to a geologic time scale (orange book, p. 152), label the suspected positions of each geologic
Period (in our current Eon) above the line. After teacher approval, color below the line to show the
position of each Period (a different color for each). **If correct done, there should be 12 divisions.
5) Label and lightly color above the line to separate and ID the start/end of the Eras. There are 3.
6) Answer the questions below.
Data pts. table
X
Think of a title for your graph here: ______________________________________
7.0
( Y, in
thousands
of
genera)
0.0
550
0
( X, time in millions of years ago, M.A. )
Questions:
1. What do you think the sudden downward drops in the line portray?
_______________________________________________________________
2. At 65 m.a., what happened?
_______________________________________________________________
3. What is the average number of years between downward drops?
Y
m.a.
Thousands
of Genera
0
14.5
38
40
50
65 *
67
100
117
148
153
175
205*
215
251*
286
300
325
330
350*
360
400
420
425
445*
460
488
517
520
542
5.25
5.1
3.9
4.1
3.6
1.8
2.8
2.0
1.7
1.3
1.5
0.8
0.6
0.9
0.5
1.3
1.2
0.9
1.5
1.2
0.8
1.6
1.2
1.5
0.8
1.5
0.6
0.3
0.6
0.01
_______________________________________________________________
4. What do you think will cause the next downward drop?
_____________________________________________________________________________