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The survey

❖ Linked from course homepage

❖ The more, the merrier. Seriously--too few responses makes it hard to draw ANY conclusions

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The exam❖ Study guide posted. It’s questions, not answers.

❖ bc that’s how you should study--ask if you can answer questions, not whether you ‘are familiar with’ or ‘have read’ answers

❖ It will focus on 1-sentence answers to directed questions

❖ These will be in a logical sequence, creating explanations & arguments

❖ Today’s lecture contains practice examples

❖ Office hours posted on homepage

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Coal. When. How.Coal. When. How.Why’d it stop?Why’d it stop?

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Da Paper

“The Paleozoic Origin of Enzymatic Lignin Decomposition Reconstructed from 31 Fungal Genomes”D. Floudas et al.Science 336 (2012): 1715-1719

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Ideas happen“...the hypothesis being tested had its origins in a flight over the Amazon Basin after being immersed in discussion of Paleozoic biogeochemistry and Bob Berner's model results suggesting that atmospheric O2 levels approached, if not exceeded 30% in the Permian. Looking down over the great forest basin, I asked: "Why isn't this a coal swamp?" The question lead to years of rummaging around and tromping across disciplines, ending with the hypothesis that biodegradation processes have gotten better through the eons.”

--Jennifer Robinson, whose work culminated in a 1990 paper cited in the

one we are perusing

http://www.scientificamerican.com/article.cfm?id=mushroom-evolution-breaks-down-lignin-slows-coal-formation

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the Carboniferous period

❖ 350 => 300 MY ago

❖ Yeah--carboniferous = essentially “it’s about the carbon”

❖ This is WHEN most coal comes from

❖ In 2009, 45% of US electricity was coal-generated

8Why isn’t it still the

Carboniferous?Several hypotheses*

❖ Climate change (colder; ice formation locks up water; sea levels drop)

❖ Coastline changes (Pangea forms, decreasing global coastline)

❖ ==> Wood started to disappear! <==

*Not mutually exclusive!!!

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What’s fiber?

❖ Why isn’t it ‘food’?

❖ 1 sentence; discuss!

10How to eat?

Source: Fig. 3-16, Sadava et al., Life, the Science of Biology, 8th ed.

Lignin: impossible to eat--even if you can digest cellulose!

Structure matters.HOW the glucoses are put together determines edible (starch) vs. not (cellulose).

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One sentence

❖ How are starch and cellulose alike?

❖ Why can we digest only one?

12Diamonds from Rust

http://www.uky.edu/KGS/coal/coalform.htm

KY Geological Survey, UK

13Making coal

❖ Peat: 55% carbon; pretty much soggy plants

❖ Lignite: 65-75% carbon

❖ Lean to rich coal: 88-92% carbon

❖ Anthracite: 95% carbonhttp://www.planete-energies.com/en/energy-sources-/coal/the-formation-of-coal-56.html

14Coalification

Lignin: hard to eatlots of O, H

Lignite: pressure, time, heatmostly C

http://www.wou.edu/las/physci/GS361/Fossil%20fuels/Coal.htm

15One sentence

What is coal?How does coal happen?

16FYI*: Where’s it at

http://www.wou.edu/las/physci/GS361/Fossil%20fuels/Coal.htm

* = “because you’re curious”, not “memorize this minutiae”

17Whoopsipedia

“Much of the carbon in the peat deposits produced by coal forests came from the photosynthetic splitting of existing carbon dioxide, which released the accompanying split-off oxygen went into the atmosphere. This process may have greatly increased the oxygen level, possibly as high as about 35 percent, making the air more breathable for animals...”

What is wrong here?

http://en.wikipedia.org/wiki/Coal_forest

18WARNING

❖ We’ve talked about this before: the following is NOT going to suddenly cause you to understand everything

❖ YOU will need to

❖ curl up with your notes

❖ perhaps replay this

❖ have the original paper

❖ Think, outline, seek mastery

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1 sentence: How do we take extant SEQUENCES and create a tree-of-history?

Which sequences are most recently derived from common ancestor?

Of many trees, how to judge which tree is correct?

Don’t worry about details yet!!!

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Resources

❖ http://www.youtube.com/watch?feature=player_embedded&v=MBeXRRTGjNE

❖ http://www.wou.edu/las/physci/GS361/Fossil%20fuels/Coal.htm