Harvard University Dentition Analysis for Mammalians Biology Question

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pnyv1285

Science

Harvard University

Description

Hey guys, I really need help with these 2 assignments. They go together so its technically one assignment. Below is just some of the info you will need so you can complete the assignments. You can get a good idea of what you will be doing, but I will give my info so you can go in and complete the assignment yourself and see all the study materials.


You will conduct an analysis of dentition for a subset of mammalian skulls. You will compile and analyze a dataset, focusing on the proportion of each tooth type (e.g., incisors out of total teeth).

REQUIRED SOFTWARE

  • Microsoft Excel - Download and save the student skull datasheet (DentitionSkull_StudentDatasheet.xlsx) from Canvas BEFORE getting started. You will need this datasheet to complete the activity.
  • Download the Mammal Skull Images from Canvas (Files - Mammal Skull Images)
    • There are skull images for 16 mammals with six image files for each:
      1. Full skull lateral
      2. Upper skull lateral
      3. Upper skull dorsal
      4. Upper skull ventral
      5. Lower skull lateral
      6. Lower skull dorsal
  • If you have difficulties locating or downloading the mammal skull images please contact the course instructor

Begin by explaining why comparing the proportion of each tooth type provides a better understanding of the relationship between diet type and dentition than just comparing the total number of each tooth type. Write your explanation in the datasheet.

Counting teeth:

Quantify the number of canines, incisors, and premolars/molars for four herbivores, four carnivores, and four omnivores. In some species it is challenging to distinguish between premolars and molars, so we will count these two tooth types together.

The jaws and teeth of mammals are bilaterally symmetrical, so each side of the jaw should contain the same number and type of teeth (Figure 1). Rather than counting every tooth, you can count the teeth on half the jaw due to the bilateral symmetry.

JawSymmetry.png

Figure 1. Bilateral symmetry of mammalian jaw results in near carbon-copy right and left sides. The number, and placement, of teeth on the left side of the jaw mirror those on the right side.

  1. Before getting started with this activity, you should have downloaded and saved the student skull Excel datasheet and mammal skull images. Formulas have been entered into the Excel datasheet to automatically calculate the proportion of each tooth type. Record your data in this datasheet as you count teeth.
  2. Classify the diet type for each skull you use to collect your data by viewing the teeth and doing some online research. Remember, this diet type classification can be subjective so you may say a species is an omnivore while someone else may consider them a carnivore. Make sure your dataset includes four species from each diet type (herbivore, carnivore, and omnivore).
  3. Count all the teeth on the right side of the upper jaw.
  4. Count the number of teeth for each tooth type (canine, incisor, premolar/molar) on the right side of the upper jaw.
  5. Count all the teeth on the right side of the lower jaw.
  6. Count the number of teeth for each tooth type (canine, incisor, premolar/molar) on the right side of the lower jaw.

ORGANIZING AND VISUALIZING DATA

Now that you have your data, you will create properly formatted plots using R and determine key trends based on these plots. Specifically, you will produce three plots:

  • Plot one should show the canine teeth proportions for the mammal skulls you selected for each diet type.
  • Plot two should show the incisor teeth proportions for the mammal skulls you selected for each diet type.
  • Plot three should show the premolar/molar teeth proportions for the mammal skulls you selected for each diet type.

Once your plots are complete, copy them into a single Microsoft Word file and add captions to each plot. Then, summarize the key trends you see in your plots in one paragraph (3 - 5 sentences). The formatting of Microsoft Word files is sometimes unpredictable during Canvas submission, so save your save plots and key trend summary to the questions as a SINGLE PDF file (e.g., SmithJoeL5BYS120). Upload this PDF file to the assignment on Canvas.

User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Explanation & Answer

First assignment

Species

Diet Type

Canines
(Upper)

Beaver
Eastern
Cotton tail
Fruit bat
White tailed
deer
Coyote
Bobcat
Cougar
Harbor seals
Badger
Gray fox
Wolverine
Opossum

Herbivore

0

0

0

2

Pre-molars
and Molars
(Upper)
8

Herbivore

0

0

0

2

10

10

Herbivore

2

2

2

4

8

12

Herbivore

0

0

0

8

12

12

Carniovre
Carniovre
Carniovre
Carniovre
Omnivore
Omnivore
Omnivore
Omnivore

2
2
2
2
2
2
2
2

2
2
2
2
2
2
2
2

6
2
6
8
6
6
6
10

6
6
6
4
6
6
4
8

12
6
8
10
8
12
12
14

14
6
6
10
10
14
12
14

Canines
(Lower)

Incisors
(Upper)

Incisors
(Lower)

Pre-molars
and Molars
(Lower)
8

Total Teeth Total Teeth
(Upper)
(Lower)

Total
Canines

Total
Incisors

Total PreMolars and Total Teeth
Molars
16
18

Proportion
Canines

Proportion
Incisors

0

0,111

8

10

0

2

10

12

0

2

20

22

0

0,091

12

18

4

6

20

30

0,133

0,2

12

20

0

8

24

32

0

0,25

20
10
16
20
16
20
20
26

22
14
14
16
18
22
18
24

4
4
4
4
4
4
4
4

12
8
12
12
12
12
10
18

26...


Anonymous
Goes above and beyond expectations!

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