Lab 3 pre-lab (spring)

This is the final lab in our introductory unit. You will participate in peer review of your scientific poster drafts and plan for your revisions before final submission. The skills and conceptual knowledge of the scientific method that you have developed in this unit will be utilized throughout the rest of our course. Many of the links and information in this unit are foundational and are also listed in our 123 Library so you can re-visit them throughout the semester. And do not worry...you will see the isopods again soon enough!
This lab will also transition us to our next unit on Evolution by exposing you to the scale of geological time.

• Introduction
• Do you know enough?
• What will we do in lab?
• LABridge

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What is Peer-Review?

We have learned about the iterative process of scientific exploration, relying on past knowledge as ​a "jumping off point" for new research questions. This type of deductive reasoning requires a large body of scientific work to be made public and available, and that the work is both valid and reliable. That often entails the process of peer review by which scientists review and critique the work of other scientists and deem it acceptable or not. You have already done some research using peer-reviewed literature. Now we are asking what that process actually entails.

Researchers write up their work as a scientific paper or manuscript which they send off to an appropriate journal. Journals range from regional (like the Journal of the Kentucky Academy of Science) to global and highly regarded (like the journal Nature or Science). Once submitted, the manuscript is sent to 3-4 anonymous colleagues to serve as "reviewers." These scientists are usually working in the same field and have proven themselves to be quality researchers. Reviewers go through the manuscript, line by line, criticizing each decision and assertion. They then decide, along with the journal's editor, if the article is valid, credible, and relevant. The final decision can be one three:

• Rejected: This article has too many flaws for publication.
• Accept with revisions: There are significant flaws, but if they can be fixed it might be publishable.
• Accepted: This article is valid and has merit, and will be published.

Most submissions are rejected; 70-95% depending on the journal. The figure in the sidebar shows some acceptance rates for popular ecology journals. Once rejected, projects are either revised and submitted to other journals or re-framed and organized into totally new questions and tests. With rejection rates this high, we can feel fairly certain that the papers that do get published are reliable and of high quality.
Instead of submitting your work to scientific journals, you will present it to your peers in class.

Peer Review form

Acceptance rates (right y-axis) for popular ecology journals. Click to enlarge.

Top reasons papers are rejected from Khadilkar (2018), in "Rejection Blues."

Watch the TedTalk. Be sure you understand how peer review works.

Read over the peer review form you will use in lab. Be sure you know what to expect.

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Important!!! You need to bring one color copy of your poster to class with you next week to participate in peer review.

How to print a slide in PowerPoint

Do you know enough about geological time?

Following peer review, we will transition to our next unit.
This is a peak into to Unit 3: Evolution.

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The formation of our planet occurred 4.56 billion years ago. That's billion...with a B. Humans have an exceptionally difficult "time" understanding time at that large a scale. You may have seen some of these weird timeline facts floating around on the internet. They are great examples of how bad we are at time.

• The gap in time between Stegosaurus and Tyrannosaurus rex was bigger than between Tyrannosaurus rex and you.
• The first pyramids where built while the woolly mammoth (Mammuthus primigenius) was still walking the Earth.
• The universe is 13.8 billion years old: If we compressed that into a year, then the dinosaurs would be wiped out on 29 December, and modern humans would appear at 11:54pm on December 31st.
• We have ve only existed as a species for 0.004% of the Earth's history.

That fact that these facts are shocking, highlights just how bad we are at understanding long expanses of time; our lives are simply too short to comprehend 1000s of years, much less billions.

Image from Australian Environmental Education. Click to enlarge.

Geological time is the expansive time scale since the creation of Earth. To make it easier to conceptualize, scientists have divided it into hierarchical sections and sub sections. Eons are the largest, which contain various eras (e.g., Paleozoic and Mesozoic), which are comprised of periods (e.g., Triassic, Jurassic) of time. Those periods can be further divided into early, middle, or late, or into specific epochs (e.g., our current Holocene epoch). Throughout geologic time, there have been several mass extinction events where 70-95% of taxa went extinct. These periods were essentially like hitting the "restart button" on all life on Earth. Some argue that we are currently in a mass extinction period, termed the Holocene or Anthropocene Extinction, because our current flora and fauna are going extinct at such an alarming rate.
We will discuss biodiversity loss more in later units. In this lab you will construct a timeline of life on Earth, to scale, by converting time to linear measurements in the metric system. Without this sense of the grand scale of geologic time, it is impossible to understand evolution...our next unit.

-Weird timeline facts from: Blaze Press and Tom Chivers at Buzzfeed UK

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Watch the YouTube videos on geological time.

Know the categories of geological time and examples.

Review extinction events including the Holocene.

what will we do in lab and how will we do it?

Lab 3 contains two exercises:

1. Peer Review- The final activity of our Introduction: You will trade your poster drafts with another group. Each group will use the poster peer review form to critique the poster and give the feedback back to the authors.
2. Geologic Timeline of Life on Earth- Transition to Unit 1 on Evolution: You will create a timeline of important events in the development of Earth, to scale, using geological time. You will convert years into linear measurements using the metric system.

Important!!!
You need to bring one color copy of your poster (8.5 x 11") to class with you next week to participate in peer review. Printing help on campus.

How to print a slide in PowerPoint

Cartoon by Nick D Kim, strange-matter.net.

If you feel confident with this material, click the bridge icon below and navigate to Blackboard to take the LABridge for this week. Be ready to be tested on this material before you go to the quiz, and make sure you have your Lab Notebook Guide ready to submit as well.

Click here to get to WKU's blackboard to take your LABridge for this week.

Lab 3 Protocol (spring)

Overview. In today's lab you will participate in peer review of your scientific poster drafts and plan for your revisions before final submission.

1. ​Exercise I. Peer review
2. Exercise II. Construction of the geological timeline of life on Earth
   

Following this lab you should be able to...

• Provide useful feedback on scientific research.
  
• Properly revise your work based on peer review.
  
• Covert measurements within the metric system.
  
• Conceptualize the scale of geological time.
  

• Exercise I
• Exercise II

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Exercise i. Peer review of poster draft

Procedure.

1. Partner up with another group and trade handouts of your poster draft.
2. Once you have another group's poster to review, open the Peer Review Form.
3. You might also want someone to open the Poster Template. You can follow it along almost like a checklist of what should be included.
4. Both the Peer Review Form and Poster Template are also available as handouts up front if you prefer to work on paper.
5. Carefully review the other group's poster draft following the form.
6. Return the form (via email if electronic) and poster handout back to the author's once you completed the peer review.
7. Open your Lab Notebook Guide for Lab 3.
8. Go over your peer review results on your group's poster.
9. Discuss how you will deal with the critiques and questions from the peer review and complete the Notebook Guide.

Peer Review form

poster template

Click to download.

Exercise II. Geological Timeline of Life on Earth

The Earth has changed dramatically and repeatedly over a history that spans nearly 5 billion years. Such immense spans of time are difficult for most of us to comprehend, so it is important for biologists to expand their sense of time. Evolutionary processes are typically very slow, in reference to our short lifetimes, and therefore impossible to comprehend without a larger temporal perspective.

To appreciate the magnitude of geologic time and the history of evolution on Earth, you will be creating a timeline of important events, scaled to a size more tangible and familiar. Our timeline is similar to the clock in the side bar. Both are intended to help you understand the scale. This exercise will introduce you to many of the topics we will cover in BIOL 123 and give you some practice using the metric system. Read over all these directions, carefully, as a group, before you start. You will construct your timeline in the hallway.
Procedure.

1. First, obtain a handout of important events in geological time.
2. You need to convert each event from TIME (i.e., “years ago” in billions, millions, thousands, etc.) to DISTANCE (i.e., meters, centimeters, mm, etc.).
3. Set one billion years = one meter for these calculations (*hint 1 year = 1 nanometer). You will use meters, centimeters, and millimeters.
4. A conversion table is located at the bottom of this page to help.
5. Complete the event table on your handout with the correct distance. The transitions, like from billions of years ago to millions of years ago (km to meters), will be the hardest parts.
6. Have your TA check your conversions.
7. Select 12 events you want to place on your timeline. Discuss these choices as a group.
8. Create an index card (or paper strip) for each event including the date in “years ago” (e.g., COMPLEX SINGLE-CELLS ORGANISMS EVOLVED: 1.6 BILLION YEARS AGO).
9. Order them from oldest to most recent in a stack (the most recent should be on top).
10. Measure out a strip of masking tape 4.56 meters long in the hallway.
11. Select one end of the tape to represent the present. This would essentially be "0 years ago." Find your first event and place it closet to you on your time line, using your converted liner measurement. For example, if your most recent event = 0.5 cm, measure 0.5 cm from the current end, make a mark on your timeline, and place the event label.
12. Place all the events in their corresponding location on your timeline.
13. Have your TA come out and check your timeline.
14. Before you leave, clean up your timeline and complete Exercise II in your Lab Notebook Guide, and check out with your TA.

You will not be able to accurately measure um and nm today but your conversions should be accurate.

Clock representation of geological time.

Calendar representation of geologic time.

Timeline of Events. You'll get this handout in lab.

Review this figure from the pre-lab as needed. Image from Australian Environmental Education. Click to enlarge.