Hominid Skull Lab - Central Bucks School District



Name: ________________________________________________________ Period: ________ Date: __________________

Hominid Skull Lab

Part 1: Gathering your data

Purpose: This lab will allow you to investigate and evaluate evolutionary relationships by examining skulls of living and extinct human relatives. You will:

1. Become familiar with the different tools and techniques used in paleo-anthropological studies.

2. Analyze important morphological features and determine their importance in predicting evolutionary relationships.

3. Use data collected to create a phylogenetic tree (family tree).

Materials: Primate skulls, ruler, calipers, protractor, human evolution chart, computer with Microsoft Word and Excel

Procedure:

1. Review Descriptions and Basis for Measurement handout (on back of data chart).

2. Complete Human Evolution Data Chart.

a. Take notes in your science journal of the exact methods you used to take your measurements for each feature.

Be consistent! You will be required to include these procedures in your final lab write-up!

b. Write “N/A” for any measurement that cannot be taken, e.g. if a jaw bone is missing teeth, etc.

Part 2: Analyzing your data

Graphing your data in Excel:

*You will be creating 4 different bar graphs to represent your data. Select a group leader to create an Office 365 excel document to share with your lab group Please remember to label the x and y axis and title your graphs. Assign a specific color to each skull specimen (ie. Alex=blue, Ann = red, etc…)

Cranial Area data

1. Select your first set of data (cranial area and specimen name). Sort from least to greatest.

2. Use Excel to make a “column graph” for this trait.

3. Format your graph so that all data is organized, colorful, and presentable, i.e. all labels must be visible.

4. Immediately after creating this graph, copy and paste it onto a Word document titled hominid skull graphs.

Facial Slope data

1. Using the second set of data, repeat the above steps 1 – 3 for facial slope.

2. Resize the two graphs so that they both fit on a single page of your Word document.

3. RE-SAVE THIS WORD DOCUMENT, ALONG WITH YOUR EXCEL SPREADSHEET.

* Follow the same procedures from above for 2 other characteristics

At this point, in your student folder, you should have saved:

• Word document, which includes your data chart along with your four graphs.

• Excel spreadsheet, which contains copies of the data.

Assign Graphing Responsibility: Determine which student will construct each graph.

|Student Name |Skull Feature to Graph |

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CONGRATULATIONS: You have now completed the second part of the lab write-up! Please make sure each member of your group has their own copy of the document and spreadsheet from Parts 1 and 2.

Part 3: Interpreting and drawing conclusions

Phylogenetic Tree (Family Tree):

There are many different hypotheses about hominid evolution. Therefore, there are different ways to explain their evolution in a phylogenetic tree (also known as a family tree). Paleontologist use age and skeletal similarities to create phylogenic tress. Your job is to illustrate the evolutionary path of hominids based on your observations during this lab. Try to use the information depicted on your graphs, showing changes from more primitive hominids to more modern. Also, try to use some (or all) of the other characteristics that you did not graph to help you decide on the “correct” evolutionary relationships.

1. On the next page of your write-up document, design a phylogenetic tree (family tree).

a. The tree must include each hominid skull you observed during this lab, arranged from more primitive to more modern.

b. The tree should NOT be linear (a single straight line); it SHOULD include different branches to show common ancestry.

c. Species must be arranged by age and connections are based on skeletal similarities.

Analysis:

You will now open a new Word document to complete Part 3 of the lab. You should discuss these questions with your peers; however, your typed responses must be completely original. This means you may NOT COPY any part of another student’s work.

Compose an Essay: This is your analysis of the data you have collected in the lab; therefore, each response should be a detailed and accurate discussion of the data. Your essay should contain a detailed analysis of the question below:

How do paleontologist construct phylogenetic (family) trees? Write a 1-2 page response that focuses on how you arranged the hominid species on your family tree. Your response should include the following:

1. Introduction: Purpose of the lab/How you constructed your tree.

2. An example of 2 species that are directly related (ancestor/descendent).

a. Based on your data/characteristics provide 2 examples that support your reasoning.

3. An example of a species that is an evolutionary dead end.

a. Based on your data/characteristics provide 2 examples that support your reasoning.

4. Conclusion: What did you learn from this lab? Cite examples.

Due Date: ______________________ Student Signature: ____________________________________

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* Part 1 and 2 will be completed with your group, and your work may be identical. The remaining written portion of this lab (Part 3) MUST be done individually. *

Format of your final lab write-up:

Your entire Word document must be formatted in 12-point Times New Roman font with 1-inch margins and 1.5 spacing. Your write-up will not be accepted if it is not formatted correctly.

Your write-up will include the following parts, in this order:

• Title page (Includes your name and group members)

• Data table

• 4 Graphs (2 on one page)

• Family Tree

• Analysis (1-2 pages)

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Remember, the data table and graphs are the only parts of your write-up that may be identical to your lab partners’.

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