“… it is highly important for us to gain some
notion, however imperfect, of the lapse of
years.”
Charles Darwin: On the Origin of Species 1859
Chapter 9: On the Imperfection of the Geological Record
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Experience DEEP TIME…
with its…
PATTERNS of
FOSSIL AGES
and its PATTERNS of
staggered ORIGINS
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Trilobites
Ferns
Brachiopods
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Ammonites
Achaeopteryx
Seymouria
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When did they live?
Long
ago?
How long?
All at once?
When?
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Animals of the Past:
Patterns in the Fossil Record
Notice the origins…
Notice the time…
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What’s “65 mya” ?
65 millions of years ago
How much is 65 mya?
How much is ONE mya?
How many human lifetimes is this?
LET’S WORK IT OUT….
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Here’s One Month…
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If each day is one inch long…
1”
… how long is a week?
…a
month?
… a year?
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If ONE YEAR is 365 inches,
how many feet is that?
365/12 = ~30 feet - or 10 YARDS
10 x 10 Yards = ? 100 Yards
So… What’s 100 yards?
Right! A FOOTBALL FIELD!
Therefore, if 1 day = 1 inch,
10 years = 1 football field!
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Looking 10 years - Back in Time!
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IF… 1 day = 1 inch,
10 years = 1 football field!
And a million
years would be…
5,700 miles!
Can you
VISUALIZE THAT?
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Not easily…
So, let’s try a different scale…
Let’s take 10 years of your life,
and reduce it to 1 millimeter!
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If you do this, 1 football field
would equal 1 million years!
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…and hundreds of millions of
years
are much easier to visualize
Let’s try this…
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You can plot 100s of millions of years on
a map of your local area…
For example, 500 mya
would only be about
30 miles away
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…or plot billions of years
within your state
the past 500 million years
the past 4.6 billion years
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All of this in
fairly familiar territory…
When you shrink 10 years of your life
into one tiny millimeter…
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a million years equals
a football field!
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So 500 million years
would be about
30 miles away…
And 50 million years
would be about
3 miles away
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LET’S DO IT!
Calculating distances for mya:
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•
•
•
•
•
•
If 1 mm = 10 yrs, then 1 fbf = 1 mya
x1000: 1000 mm (= 1 meter) = 10,000 yrs
x100: 100 meters = 1,000,000 yrs = 1 mya
1 meter ≈ 1 yard, so…
100 m ≈ 100 yards = 1 football field = 1 mya
x10: 10 fbf = 1000 meters = 1 km = 10 mya
10 mya = 1 km = 0.6 mile
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Calculating distances for mya…
Continued…
• 10 mya = 1 km = 0.6 mile
• So 100 mya = 6 miles
so… 6 miles = 1
100 mya
• So… Desired Distance = 6 miles
for Desired Time 100 mya
• SO… DD = DT x 0.06
• Example: If DT is 65 mya: DD = 65 x 0.06
DD = 3.9 miles
• OR… Use the table provided!
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Geolgical Time Scale
FBF km mi
mya mi cm
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Finding MAP Distance on Map
Find the map scale:
Measure its length:
5 mi
1.9
cm
So, on this map, 1.9 cm = 5 miles
Map Distance = 1.9 cm
Desired Dist. 5 mi
OR… MD = DD x 0.38
Example: If Desired Distance is 13.2 mi.,
MD = 13.2 x 0.38 = 5.02 cm
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Or… Check the Geolgical Time Scale
This Map Scale: 5 mi = 1.9 cm
FBF km mi
mya mi cm
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And plot that Map
Distance as the
radius of a circle
or arc centered
from your school…
13.2 miles ≈ 5 cm
(for 220 mya) or
distance from SJSU
to Cupertino!
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Now, when you see the
10s of millions of years
that separate the origins
of the different
classes of vertebrates,
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you will have a much better sense
of the vastness of that time.
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Your Own Vertebrate Timeline
In order to get more familiar with
those vertebrate classes, and
when their first fossils appeared,
You may be asked to make your
very own
“Chronology of Fossil Vertebrates”
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You will use this chart showing basic
vertebrate traits for all the groups…
PLUS a set of distinct
new modifications
New Traits, added when each
new group appears…
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Chronology of
Fossil Vertebrates
On this timeline
grid, mark when
the first fossils for
each class
appeared, starting
at the lower left,
and shifting to the
right with each
class as shown here…
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Chronology of
Fossil Vertebrates
Now label each of
those first fossils,
along with their
additional traits
Notice how
many millions of
years between
the beginnings
of each group…
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Chronology of
Fossil Vertebrates
Then draw vertical
lines from each
“first fossil” up to
the top line that
represents “NOW”
(except for the
Pre-mammals, that
became extinct
about 60 mya),
and LABEL EACH.
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ADDED
FEATURES:
You could vary the
thickness of each
line to show
relative diversity
in each group
through time,
and/or, you could
find and add
pictures of typical
members of each
group.
Or, make a larger version - for the wall
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Notice, by the way, that each class has the
same traits as the previous class…
PLUS a set of distinct
new modifications
that are unique to each
new class…
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We ALSO find many fossils showing
gradual transitions from class to class…
fish to amphibian…
X
X
X Tiktaalik - fish
with wrist bones!
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Transitions from pre-mammal to mammal…
Early Mammals
Early Pre-Mammals
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Transitions from pre-whales to whales…
with hippos as
their closest
living cousins!
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Transitions from pre-humans to humans…
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THIS all suggests a
biological connectedness…
LIKE THIS…
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And what is this
biological connectedness called?
Right….EVOLUTION!
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Did this experience
give you a better sense of
geological time?
Did this experience
reveal patterns of fossils
that you didn’t realize before?
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I hope you enjoyed these…
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Appendix: Geological Time Scales
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Geological Ages - 2004
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Geological Time - Over Time (since 1937)
The next 2 slides show how the
increased precision of radiometric
dating over the years has stabalized
the timing for the major geological
periods - with little change since
1990…
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Geological Time - Over Time (since 1937)
PALEOZOIC
MESOZOIC
1990
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Geological Time - Over Time (since 1937)
CENOZOIC
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LOOKING FOR TEACHERS TO
BETA-TEST
PATTERNS IN TIME
on the ENSI website
All levels - 5th through college
Try it, and please send me
your feedback
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