Bones Of Contention Lab Questions Analysis Questions for Part A: 1. What is the
ID: 39667 • Letter: B
Question
Bones Of Contention Lab Questions
Analysis Questions for Part A:
1. What is the difference between cranial and post-cranial fossils?
2. Based on the available evidence, what creature do you think was the earliest biped?
3. What is the earliest sign of large leg bone? Next after that?
4. In addition to femur orientation, which features proved useful in helping you narrow your group(s)?
5. Are there any fossil records in your groups of cranial and post-cranial bipeds that might be the same species? Why?
Analysis Questions for Part B:
6. Describe what/how cranial features can tell us about a hominins diet.
7. Why is diet significant? What can it tell us about a species?
8. Looking over the groups you created, what are the differences in cranial capacity between groups with hard diets vs. those with a less robust chewing complex/features related to a softer diet? (You may need to show the column for Cranial Capacity.) Describe this relationship.
9. Compare the dates of the groups you created based on diet particularly those with a hard diet and the earlier species with a soft diet. Do you notice any overlap in when they lived? What does this tell you about the possible relationship between these species?
Analysis Questions for Part C:
10. What role do cresting and post-orbital constriction have in determining brain size?
11. According to this database, what is the earliest species to use tools? What makes this fossil similar or different from others like it?
12. Who were the earliest users of symmetrical tools? What else do you notice about species that used symmetrical tools?
13. Why is cranial capacity a deceptive indicator of evolutionary advancement?
14. Provide an explanation for the rapid growth in brain size in the most recent human ancestors.
15. Taking it Further: Though the purpose of the nasal margin is unclear, it is a clear species differentiator. Examine fossils according to Nasal Margin and describe how that characteristic helps differentiate species.
16.
Mystery ID
Date
Descriptive name or species classification
Key evidence
1
6-7 mya
2
2.9-3.3 mya
3
3 mya
4
2.5 mya
5
1.8 mya
6
1.7 mya
7
1.51-1.56 mya
8
220,000-580,000 ya
9
150,000-250,000 ya
10
40,000 ya
Mystery ID
Date
Descriptive name or species classification
Key evidence
1
6-7 mya
2
2.9-3.3 mya
3
3 mya
4
2.5 mya
5
1.8 mya
6
1.7 mya
7
1.51-1.56 mya
8
220,000-580,000 ya
9
150,000-250,000 ya
10
40,000 ya
Explanation / Answer
1. What is the difference between cranial and post-cranial fossils?
The main difference between cranial and postcranial fossils are
Cranial fossils only gives you information about the skull
Post-cranial fossils will give you information about all or part of the skeleton leaving skull alone.
Through cranial fossils, we can get information regarding the positioning of the Foramen Magnum (the place where spine enters the skull).
Through post-cranial fossils, we can know the shape and position of the pelvis, shinbones, femur and also finger bones, in addition to this, it also provides information regarding relative lengths of the limbs.
2. Based on the available evidence, what creature do you think was the earliest biped?
By using the position of Foramen Magnum, scientists were able to identify the earliest biped as Sahelanthropus tchadensis. While observing, they found that even though at the back of the skull, its foramen magnum is located, the slightly forward position indicates that it was bipedal, and it is the earliest bipedal.
3.What is the earliest sign of large leg bone? Which is the next earliest?
It is the Australopithecus afarensis (2.9 - 3.3 mya), which is the earliest sign of large leg bone and the next earliest is Australopithecus afarensis (2.5 mya).
4. In addition to femur orientation, which features proved useful in helping you narrow your group(s)?
Largest limb and pelvis shape are the features which actually were very useful in helping us to narrow wth group. Regarding bipedalism, the other postcranial data which as useful was shinbones and fingers, but they have provided little data.
5. Are there any fossil records in your groups of cranial and post-cranial bipeds that might be the same species? Why?
Based on the bipedalism and close dates, we can keep both AL 288-1/Lucy: 2.9–3.3 mya from the post-cranial bipeds with AL 444-2 in the same species and evidence suggest that they might be both A.afarensis. A.garhi: 2.5 mya is considered as the next closest mystery relative.