Note that the illustrations that accompanied these questions have not been posted.
Note also that I will add further instructor comments to clarify the reasons for answers.
Grading:
· I assume that questions in which the class on average scored only slightly better than random (or worse) means that the topic was not taught in class, it wasn’t taught well, or something about the teaching or question was misleading.
· I therefore compiled all answers to all questions in a spreadsheet, and calculated % correct for each problem.
· Problems for which the class as a whole scored poorly are treated as follows: anyone who got the problem correct receives credit for question and this is tallied in the final score; for students with an incorrect answer either the problem is not counted at all (weighting = 0) or the weighting of the problem is decreased to between 0 and 1).
Theoretical example [this example problem 1 and 2 do not correspond to your exam]:
Problem 1: question = 2 points, weighting = 1.0
Problem 2: question = 1 point, weighting = 1.0 if correct, 0.33 if incorrect
Say you got problem 1 correct and problem 2 wrong. You would receive [(1.0 x 2) + (0.33 x 0)]/[(1.0 x 2)+(0.33 x 1)] = 2/2.33.
Say you got both problems right. You would receive [(1.0 x 2) + (1.0 x 1)]/[(1.0 x 2)+(1.0 x 1)] = 3/3.
· This means that each person has a unique point total. For example, someone with a perfect score on this exam would score 47.5 out of 47.5, + 2 points extra credit. Another person might score 31.8 of 42.6 + 2 points extra credit.
· The average class score using this system was 38.6 of 43.8 (88%) + 1.7 points average extra credit = 92%.
· A more literal average class score (without deleting and low weighting of problems with unusually low success rates) was be 36.9/47.5 = 78%; this plus 1.7 average points extra credit = 38.6/47.5 = 81%. Thus, deleting problems with low class success rates raises the average grade by about 10%. Another way of saying this is that 10% of the problems were too hard or were somehow misleading.
1. Roy Chapman Andrews led famous fossil hunting expeditions to Mongolia in the 1920’s; some have claimed he was the model for Indiana Jones. Andrews found the first extensively preserved dinosaur egg nests, and many well known dinosaur and mammal skeletons. Which of the following do you think is true? Write T if it is fully true, otherwise write F for false.
__F___ Great fossil finds are all made in remote places like Siberia, East Africa, and Mongolia, because that’s where ancient animals lived. (99% of class got this correct; question = 1 point, weighting = 1.0)
__T___ There are still a large amount of field work today for vertebrate skeletons, and the rate of new finds is faster than at any previous time. (86% of class got this correct; question = 1 point, weighting = 1.0)
__F___ Good research demands specializing in one particular kind of fossil collecting per expedition, or the research may become distracted with irrelevant information. (80% of class got this correct; question = 1 point, weighting = 1.0)
Instructor comment: It is true that expeditions do not collect every conceivable kind of information, but in our discussions in class we frequently made reference to the fact that multiple kinds of fossil evidence are used to reconstruct ancient environments, even when one sort of fossil (say, a mastodon or mammoth) is the focus of the expedition.
__F___ Most expeditions today use special machines that find the bones in the ground before anyone begins to dig. (55% of class got this correct; question = 1 point, weighting = 1.0 if correct, 0 if incorrect)
Instructor comment: Perhaps it was confusing that there were class discussions about ground penetrating radar being used experimentally in looking for mastodon skeletons, and of course there is the scene in the first Jurassic Park; we did, however, spend some time discussing the fact that finding bones by radar or other sensing techniques is only at the most exploratory stages.
__T___ Some valuable finds are first made by land owners or native peoples. (97% of class got this correct; question = 1 point, weighting = 1.0)
2) These men are putting together a model of a Triceratops skull, which is one of the largest known land animal skulls. The photograph is from the American Museum of Natural History in NY City. Evaluate the following in confidence we might have in these men’s reconstruction: use “1” for well-known, “2” for some possibility of knowledge, and “3” for speculation without fossil evidence
__3___ position and size of skin folds
(39% of class got this correct [most thought it was 2]; question = 1 point, weighting = 1.0 if correct, 0 if incorrect)
__1___ shape and size of frill
(51% of class got this correct [most others thought it was 2]; question = 1 point, weighting = 1.0 if correct, 0.33 if incorrect)
__1___ shape and size of horns
(97% of class got this correct; question = 1 point, weighting = 1.0)
__3___ skin color
(98% of class got this correct; question = 1 point, weighting = 1.0)
__2___ skin texture
(18% of class got this correct [most all thought it was 3]; question = 1 point, weighting = 1.0 if correct, 0 if incorrect)
3. In 1999 a group led by Frenchman Bernard Buigues excavated a woolly mammoth preserved in ice that hadn’t melted since the last ice age. Find all the statements that are true.
a) A mammoth had never been found in ice before. (92% of class got this correct; question = 1 point, weighting = 1.0)
b) Mammoths are occasionally found in ice (a few per century), but this was the first one to be unfrozen a little at a time for study of a variety of features. (82% of class got this correct; question = 1 point, weighting = 1.0)
c) Frozen mammoths potentially inform us what exactly mammoths ate. (77% of class got this correct; question = 1 point, weighting = 1.0)
d) Frozen mammoths reveal for the first time the social behavior of ancient mammals. (95% of class got this correct; question = 1 point, weighting = 1.0)
4. The Hyde Park mastodon apparently died in the pond in which it was buried and became a fossil. Therefore the skeleton was essentially complete (except for a few bones lost when the pond was being dredged, before the mastodon was excavated) and extremely well preserved. Mammoths are also known from such settings and from finds in Ice Age ice. Based on this information, for which type of animal is the reconstruction better known?
a) They are the same.
b) Mastodons
c) Mammoths (31% of class got this correct; question = 1.5 points, weighting = 1.0 if correct, otherwise 0)
Extra credit
5. One of these animals is an American mastodon and one is a woolly mammoth. Which is the mastodon?
A (93% of class got this correct; question = 1.0 extra credit points)
B
6. This scene is from the Late Cretaceous Period, which we haven’t studied yet, but you can use your knowledge of fossilization to figure out the potential that the animals in the picture will become fossils. . Using the numbers 1 to 4, rank from best to worst the quality of the fossil record you’d expect from the organisms in the picture:
_1____ A- bones of large carnivorous dinosaur in pond in the background
(93% of class got this correct; question = 0.67 points, weighting = 1.0)
_3____ B- bones of Triceratops on land in the foreground
(90% of class got this correct; question = 0.67 points, weighting = 1.0)
_2____ C- bones of small mammal in the foreground
(93% of class got this correct; question = 0.67 points, weighting = 1.0)
7. This scene is a reconstruction of an ancient habitat. It is based on a wide variety of fossil evidence. Use your knowledge of what kinds of things are most likely to be preserved. Using the numbers 1 to 4, rank from best to worst the quality of the fossil record you’d expect from the organisms in the picture:
_4____ A- butterflies
(73% of class got this correct; question = 0.5 points, weighting = 1.0)
_1____ B- tree pollen [responses were evenly divided among 2, 3, and 4]
(11% of class got this correct; question = 0.5 points, weighting = 1.0 if correct, otherwise 0)
_3____ C- bird bones
(44% of class got this correct; question = 0.5 points, weighting = 1.0 if correct, otherwise 0.33)
_2____ D- elephant bones [most thought this was 1]
(10% of class got this correct; question = 0.5 points, weighting = 1.0 if correct, otherwise 0)
8. These are famous skeletons collected around the turn of the 20th century and housed by the American Museum of Natural History. “A” is a so-called “dire wolf,” a very large wolf that lived during the Pleistocene. “B” is an unusual large horned herbivorous mammal (Brontops) from about 50 million years ago. “C” is the so-called “sail-back reptile,” Dimetrodon, which is a mammal-like reptile from about 270 million years ago.
Assuming that there is no fossil evidence other than these kinds of fossil skeletons, which do you suppose could be reconstructed in a life-like 3-D animation with the most confidence of accuracy?
a) A, because it is most similar to an animal that is alive today that can provide the basis for soft parts and behavior
(85% of class got this correct; question = 2.0 points, weighting = 1.0)
b) A, because it is not as old and so the bones are probably better preserved
c) B, because it is largest, so the muscle scars are larger and thus the muscles are easier to reconstruct
d) C, because it more interesting to paleontologists, and so has been better studied
9. Which of these three lived during the Cenozoic Era?
A (80% of class got this correct; question = 1 point, weighting = 1.0)
B (63% of class got this correct; question = 1 point, weighting = 1.0 if correct, otherwise 0.17)
C (98% of class got this correct; question = 1 point, weighting = 1.0)
10. Which of these 3 lived during the Ice Ages?
A (86% of class got this correct; question = 2.0 points, weighting = 1.0)
B (76% of class got this correct; question = 2.0 points, weighting = 1.0)
C (93% of class got this correct; question = 2.0 points, weighting = 1.0)
11. Indricotherium, a hornless rhinoceros, is perhaps the largest land mammal known. There was a general trend toward larger size in Cenozoic mammals, a trend seen in various other kinds of animals as well. Which of the following might have been advantages to greater size in Indricotherium?
a) more offspring
b) greater resistance to predation
(100% of class got this correct; question = 2.0 points, weighting = 1.0)
c) speed
d) better barbequed ribs
12. This depiction of Australopithecus afarensis draws on two sources of information: fossil bones and trackways. Using what you learned about study of ancient hominids, what do you suppose is intended to be the significance of this reconstruction? It is intended to show that....
a) ....pregnant A. afarensis looked not unlike pregnant Homo sapiens
b) ....A. afarensis lived in the shadow of volcanic eruptions, which undoubtedly played a role in their adaptation to their environment’
c) ....A. afarensis ears, hair, and other skin features were beginning to take on a modern human appearance
d) ....A. afarensis walked upright in a manner fairly similar to modern humans
(97% of class got this correct; question = 2.0 points, weighting = 1.0)
13. This diagram shows a hypothesis for the migration of Homo sapiens out of Africa and around the world, between about 100,000 and 15,000 years ago. It is perhaps the consensus view among paleoanthropologists today, and is called the “out of Africa” model. There are a number of other paleoanthropologists, however, who believe that:
a) ....the peoples of each continent are actually different species of Homo
b) ....Homo sapiens left Africa primarily by boat across the Atlantic, Indian, and Pacific Oceans, rather than across land
c) ....Homo sapiens evolved from Homo erectus independently on several different continents
(83% of class got this correct; question = 2.0 points, weighting = 1.0)
d) ....all of the above
14. Which of the following are true?
_(F)___ The fossil record of whales is fairly poor, because whale bones are too big to fossilize well.
(100% of class got this correct; question = 1 point, weighting = 1.0)
_(F)___ Extensive excavations of fossil whales have been made in the deep sea, several miles below the surface, where bones are not disturbed by weather or waves.
(73% of class got this correct; question = 1 point, weighting = 1.0 if correct, otherwise 0.85)
_T___ The fossil record of whales is fairly good along coastlines, where sedimentary rocks may be exposed above sea level, and in rocks from freshwater habitats.
(95% of class got this correct; question = 1 point, weighting = 1.0)
_(F)___ The fossil record of whales is now nearly complete; probably few fossil skeletons remain buried.
(93% of class got this correct; question = 1 point, weighting = 1.0)
15. Among these three fossil whales, which would you guess is most similar to the earliest known ancestors of whales?
A (65% of class got this correct [most of the rest thought it was C]; question = 1.5 points, weighting = 1.0 if correct, otherwise 0.92)
B
C
Extra credit:
16. In the Walking with Beasts video we watched about early whales, a new and complete skeleton of Basilosaurus was found that contained a feature not found on this older illustration or the accompanying reconstruction. What was this feature?
a) a significant nose horn
b) a large dorsal fin
c) small back legs (82% of class got this correct; question = 1 point extra credit)
d) large armor plates
17. In this diagram, the appearance of major groups of mammals is shown. Time runs vertically, with recent at the top. Which three epochs are missing from the top of the chart, at the letter “A”?
a) ___Holocene______________________ b) __Pleistocene___________________ c) __Pliocene_____________________
(in total for class, about 57% of potential credit was awarded for this question; question = 1 point for each of a, b, and c, weighting = 1.0)
Which era is represented in this figure? d) __Cenozoic _______________________
(in total for class, about 87% of credit was award for this question; question = 1 point, weighting = 1.0)
18. This chart represents is a general representing of many thousands of fossil skeletons found around the world. Why do you suppose it is presented like this, with modern animals on the top?
a) Modern animals are superior in adaptation, so metaphorically belong at the top.
(99% of class got this correct [that is, did not choose this answer]; question = 0.5 points, weighting = 1.0)
b) Evolution is sometimes depicted as a tree, and branches grow upward.
(68% of class got this “correct” [that is, did not choose this answer], but weighting = 0 because of ambiguity stemming from logical merit of this answer)
c) Younger sediments accumulate on top of older sediments.
(68% of class got this correct; question = 0.5 points, weighting = 1.0 if correct, 0.55 otherwise)
d) A 19th century printing mistake resulted in a long-standing tradition that we still follow today.
(100% of class got this correct [that is, did not choose this answer; question = 0.5 points, weighting = 1.0)
19. This diagram represents layers of rock, especially volcanic ash – little grains of volcanic rock that pile up rather like other sediments. Which rocks do you think are older?
a) at point A
b) at point B
(100% of class got this correct; question = 1 point, weighting = 1.0)
20. In this rock are petrified forests – forests that were buried by the ash, and became extremely well preserved. Overall, which do you suppose is the most common kind of preservation of fossils?
a) fossils in volcanic ash like these petrified forests
b) fossils in mud and sand (from weathering) in aquatic settings
(91% of class got this correct; question = 2 points, weighting = 1.0)
c) fossils in ice
d) fossils in caves