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“… 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. Patterns in Time. DEEP TIME. Experience DEEP TIME… with its….

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## “… it is highly important for us to gain some notion, however imperfect, of the lapse of years.”

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**“… it is highly important for us to gain some notion,**however imperfect, of the lapse of years.” Charles Darwin: On the Origin of Species 1859Chapter 9: On the Imperfection of the Geological Record**Experience DEEP TIME…with its…**PATTERNS of FOSSIL AGES and its PATTERNS of staggered ORIGINS**FOSSILS...**Trilobites Ferns Brachiopods**Ammonites**Achaeopteryx Seymouria**When did they live?**Long ago? How long? All at once? When?**Animals of the Past: Patterns in the Fossil Record**Notice the origins… Notice the time…**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….**If each day is one inch long…**1” … how long is a week? … a month? … a year?**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!**IF… 1 day = 1 inch, 10 years = 1 football**field! And a million years would be… 5,700 miles! Can you VISUALIZE THAT?**So, let’s try a different scale…**Not easily… Let’s take 10years of your life,and reduce it to 1 millimeter!**If you do this, 1 football field would equal 1**million years!**…and hundreds of millions of yearsare much easier to**visualize Let’s try this…**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**…or plot billions of years within your state**the past 500 million years the past 4.6 billion years**All of this in fairly familiar territory…**When you shrink 10 years of your lifeinto one tiny millimeter…**So 500 million years would be about 30 miles away…**And 50 million years would be about 3 miles away**LET’S DO IT!Calculating distances for mya:**• If 1 mm = 10 yrs, then 1 fbf = 1 mya • x1000: 1000 mm (= 1 meter) = 10,000 yrs • x100:100meters = 1,000,000 yrs = 1 mya • 1 meter ≈ 1 yard, so… • 100m ≈ 100 yards = 1 football field = 1 mya • x10:10 fbf = 1000 meters = 1 km = 10 mya • 10 mya= 1 km = 0.6 mile**Calculating distances for mya…Continued…**• 10 mya= 1 km = 0.6 mile • So100 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 0.06DD = 3.9 miles • OR… Use the table provided!**Geolgical Time Scale**FBF km mi mya mi cm**5 mi**1.9 cm Finding MAP Distance on Map Find the map scale: Measure its length: So, on this map, 1.9 cm = 5 miles Map Distance=1.9 cmDesired 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**Or… Check the Geolgical Time Scale**This Map Scale: 5 mi = 1.9 cm FBF km mi mya mi cm**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) ordistance from SJSUto Cupertino!**Now, when you see the 10s of millions of years that separate**the originsof the different classes of vertebrates,**you will have a much better sense of the vastness of that**time.**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” Your Own Vertebrate Timeline**You will use this chart showing basic vertebrate traits for**all the groups… PLUS a set of distinctnew modificationsNew Traits, added when each new group appears…**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…**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…**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.**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**Notice, by the way, that each class has the same traits as**the previous class… PLUS a set of distinctnew modificationsthat are unique to each new class…**We ALSO find many fossils showing gradual transitions from**class to class… fish to amphibian… X X X Tiktaalik - fishwith wrist bones!**Transitions from pre-mammal to mammal…**Early Mammals Early Pre-Mammals**Transitions from pre-whales to whales…**with hippos astheir closestliving cousins!**And what is this biological connectedness called?**Right….EVOLUTION!**Did this experience give you a better sense of geological**time? Did this experience reveal patterns of fossilsthat you didn’t realize before?**I hope you enjoyed these…**Patterns in Time**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…**Geological Time - Over Time (since 1937)**PALEOZOIC MESOZOIC 1990

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