assignment

Read the prompt below.  Click on the document link if you'd like to see the prompt in a Word document with alternative text, opens in a new window.  GeologicTimeScaleADA 

Concept      

To better understand the concept of geologic time, your assignment is to produce a time-scale illustration that is true to scale and reflects some of the important events in the history of the earth (see list below, you only have to put the events in boldface on your illustration). The exercise requires that you produce an illustration to share with the class on our discussion board and that you write a short essay that: (1) discusses why you chose the metaphor you used; (2) shows an example of one of your math calculations; and (3) discusses what you learned from this exercise including your perspective of where humans fit in the grand scheme of things. Have fun! Be creative! No Illustration is too silly, as long as your math is correct, and your choice has meaning to you. Your instructor appreciates unusual and distinctive efforts.  However, if you’re not feeling very creative on this one, just pick a simple approach and do a neat, accurate job.  Don’t get hung up obsessing over your approach, pick something that works for you and do it.  Remember that you are trying to convey a sense of Earth’s entire history with an illustration so neatness counts, color coding is helpful, pictures are also useful.  Email me with any questions that you have.

Posting your Work

You can produce your illustration in any way that you choose.  It can be a Word document, scan of a hand drawn picture, graphic design, video, photograph…. Whatever best shows your work.  It does need to be easily visible and clear so that your fellow students and your instructor can clearly see your work.  You can attach it to your thread or embed it in your essay.

How To The method used to determine a true-to-scale illustration will be similar for all choices.  Units in the illustration can be in time, distance, volume, mass, etc. depending upon what type of illustration you choose to work with. The general equation used to generate numbers in your illustration which will be true to scale is:

 For example, suppose your illustration uses distance as its "guiding light." Remember, the use of time, volume, or mass in an illustration would be just dandy. Since we are using a distance illustration as an example here, a football field with a length of 100 yds will do just fine. To find where on the football field, let's say, the "first oxygen" yard mark would be, you would set up the ratio shown below and solve for X:

HINT:  Divide 2,700,000,000 by 4,600,000,000 then multiply by 100 to solve for X.

The "build-up of oxygen" location on the football field would be (X) yards away from the goal line of your choice!  (The example above assumes that the zero-yard line is the present day and the 100 yd line is the beginning of earth history.)

Example

Here is a great example of this concept from the University of Saskatchewan.  Your illustration will have more dates than this simplified one. 

Citation:  University of Saskatchewan  (citationforillustration)

Resources

I don’t usually cite Wikipedia, but I found their article on the geologic timescale to be very good.  They also have some illustration examples that might help you get started.  Here is the citation:  GeologicTimescale

Below is a very condensed table of events in our long Earth history.  There is a lot more to our history that is covered in your textbook.  You only have to use the events in bold on your illustration! 

Event	Years before present
Present	0
Modern man	10,000
Neanderthal man	100,000
First use of fire	500,000
Homo erectus	1,300,000
Linking of North and South America	1,500,000
Oldest stone tools	1,600,000
Beginning of Quaternary period (end Tertiary/Neogene)	1,800,000
Australopithecus (early hominids)	3,000,000
Beginning of Antarctic ice caps	10,000,000
First evidence of ice at the poles	25,000,000
Collision of India with Asia	40,000,000
Start of global cooling (to present day)	40,000,000
Early horses	50,000,000
Separation of Australia and Antarctica	50,000,000
Early primates	57,000,000
Alps form	60,000,000
Beginning of Tertiary/Paleogene period (recent life)	65,000,000
Dinosaurs became extinct	65,000,000
Rocky Mountains form	80,000,000
Cretaceous Period begins (Jurassic ends)	140,000,000
Early flowering plants	150,000,000
Early birds and mammals	180,000,000
Opening of Atlantic Ocean	200,000,000
Jurassic Period begins (end Triassic)	208,000,000
First dinosaurs	215,000,000
Triassic Period begins	245,000,000
Final assembly of Pangaea	280,000,000
Early trees, formation of coal deposits	318,000,000
First reptiles	340,000,000
Beginning of Carboniferous/Mississippian period (end Devonian)	360,000,000
First insects	400,000,000
Early land plants	450,000,000
Early fish	490,000,000
Beginning of Ordovician period (end Cambrian)	510,000,000
Early shelled organisms	544,000,000
Beginning of Cambrian period (end of Precambrian time) - rise of multicellular organisms	544,000,000
Beginning of Paleozoic (ancient life) Era	544,000,000
Early multi-celled organisms	700,000,000
Breakup of early supercontinent	800,000,000
First known animals	1,200,000,000
Formation of early supercontinent (Rodinia)	1,400,000,000
Buildup of free oxygen in atmosphere	2,700,000,000
Early bacteria & algae	3,400,000,000
Oldest known Earth rocks	3,960,000,000
Formation of Earth's atmosphere	4,200,000,000
Formation of the Moon	4,500,000,000
Precambrian time begins	4,600,000,000
Origin of earth	4,600,000,000

 

Grading

30% Essay:  Well written, correct grammar and punctuation.  Covers all three of the prompt questions in interesting, accurate detail.  Shows time spent reflecting on Earth’s history, an understanding of geologic time, and thoughtful response to this lab as a personal experience.  Is not overly brief.

70% Geologic Time Illustration:  Illustration is clear, dates are readable, math is correct.  Appropriate use of color, pictures, symbols etc… to enhance understanding of presentation.  Illustration shows creativity in approach and neatness in execution.