Last visit was: 18 Nov 2025, 16:12 It is currently 18 Nov 2025, 16:12
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
705-805 Level|   Method of Reasoning|   Weaken|         
User avatar
noboru
User avatar
Joined: 16 Jul 2009
Last visit: 15 Jan 2020
Posts: 539
Own Kudos:
9,464
 [49]
Given Kudos: 2
Schools:CBS
WE 1: 4 years (Consulting)
Posts: 539
Kudos: 9,464
 [49]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 15 May 2010, 06:35
6
Kudos
Add Kudos
43
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

85% (hard)

Question Stats:

54% (02:28) correct 46% (02:35) wrong based on 1547 sessions

History

Date
Time
Result
Not Attempted Yet
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpretation of certain footprints that were left among other footprints in hardened volcanic ash at site G. Dr. Tyson claims they are clearly early hominid footprints since they show human characteristics: a squarish heel and a big toe immediately adjacent to the next toe. However, since the footprints indicate that if hominids made those prints they would have had to walk in an unexpected cross-stepping manner, by placing the left foot to the right of the right foot. Dr. Rees rejects Dr. Tyson’s conclusion.

Which one of the following, if true, most seriously undermines Dr. Tyson’s conclusion?

(A) The foot prints showing human characteristics were clearly those of at least two distinct individuals.

(B) Certain species of bears had feet very like human feet, except that the outside toe on each foot was the biggest toe and the innermost toe was the smallest toe.

(C) Footprints shaped like a human’s that do not show a cross-stepping pattern exist at site M, which is a mile away from site G, and the two sets of footprints are contemporaneous.

(D) When the moist volcanic ash became sealed under additional layers of ash before hardening, some details of some of the footprints were erased.

(E) Most of the other footprints at site G were of animals with hooves.

Source: LSAT
ShowHide Answer
Official Answer
B
Most Helpful Reply
User avatar
TehJay
User avatar
Joined: 06 Aug 2010
Last visit: 19 Jun 2013
Posts: 123
Own Kudos:
810
 [15]
Given Kudos: 5
Location: Boston
Posts: 123
Kudos: 810
 [15]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 08 Oct 2010, 07:49
13
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Going with A for the first one and B for the second one.

noboru
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpretation of certain footprints that were left among other footprints in hardened volcanic ash at site G. Dr. Tyson claims they are clearly early hominid footprints since they show human characteristics: a squarish heel and a big toe immediately adjacent to the next toe. However, since the footprints indicate that if hominids made those prints they would have had to walk in an unexpected cross-stepping manner, by placing the left foot to the right of the right foot. Dr. Rees rejects Dr. Tyson’s conclusion.

The disagreement between the two paleontologists is over which one of the following?

Dr. Tyson thinks that the evidence shows the footprints belong to early hominids due to the shape of the footprints, while Dr. Rees believes they can't belong to early hominids because of the walking pattern. Sounds like they're disagreeing over interpretations of different aspects of the evidence.

(A) the relative significance of various aspects of the evidence Bingo
(B) the assumption that early hominid footprints are distinguishable from other footprints Clearly they agree with that, or this disagreement wouldn't happen to begin with
(C) the possibility of using the evidence of footprints to determine the gait of the creature that made those footprints The gait has been determined and is the evidence that Dr. Rees is using, so this is not a point of dissention
(D) the assumption that evidence from one paleontologic site is enough to support a conclusion They're both drawing conclusions, neither one is arguing that no conclusion can be drawn
(E) the likelihood that early hominids would have walked upright on two feet Dr. Rees didn't say anything about this possibility

Which one of the following, if true, most seriously undermines Dr. Tyson’s conclusion?

(A) The foot prints showing human characteristics were clearly those of at least two distinct individuals. This would strengthen Dr. Tyson's conclusion by weakening Dr. Rees's, because it would open the possibility of the strange pattern of footprints being caused by two people walking in a particular fashion, causing the overlap of footprints
(B) Certain species of bears had feet very like human feet, except that the outside toe on each foot was the biggest toe and the innermost toe was the smallest toe. This would explain the "cross-stepping pattern" - because the bear's feet look the same as a human's, except they're essentially reversed. So the footprint from the left foot would look like the right foot, and vice versa. This strengthen's Dr. Rees's position, by giving a reason to believe the footprints might belong to the bear, and thereby weakens Dr. Tyson's conclusion.
(C) Footprints shaped like a human’s that do not show a cross-stepping pattern exist at site M, which is a mile away from site G, and the two sets of footprints are contemporaneous. Strengthen's Dr. Tyson's argument by showing that the cross-stepping pattern might be an anomaly
(D) When the moist volcanic ash became sealed under additional layers of ash before hardening, some details of some of the footprints were erased. I originally answered this by POE until I started typing this post and realized that B is a much better answer. This doesn't really affect either argument, since both conclusions are being made from the same set of prints.
(E) Most of the other footprints at site G were of animals with hooves. Totally irrelevant.
Show more
General Discussion
User avatar
VeritasPrepMimi
User avatar
Veritas Prep GMAT Instructor
Joined: 28 Jul 2010
Last visit: 19 Nov 2010
Posts: 11
Own Kudos:
14
 [1]
Affiliations: Veritas Prep
Posts: 11
Kudos: 14
 [1]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 08 Oct 2010, 09:53
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This explanation is very clear and thorough! I would just add one thing for those trying to decide between answers A) and B) on the second question. It's important to keep track of what conclusion the scientists are arguing over: whether or not the tracks are evidence of humans. Answer A) in the second question does not call that conclusion into question. It just says that there might be some disagreement about HOW MANY humans there are, without questioning the conclusion that humans were present.
avatar
sheolokesh
avatar
Joined: 04 Jan 2014
Last visit: 06 Jun 2015
Posts: 51
Own Kudos:
56
 [1]
Given Kudos: 20
Posts: 51
Kudos: 56
 [1]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 08 Apr 2015, 05:55
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Tyson claims they are clearly early hominid footprints since they show human characteristics: "a squarish heel and a big toe immediately adjacent to the next toe."

(B) Certain species of bears had feet very like human feet, except that the "outside toe on each foot was the biggest toe and the innermost toe was the smallest toe."
Even Bear has what Tyson explained. But Tyson's explanation dint have the other char of bear foot print.. Weakens the conclusion. Hence the answer..
User avatar
Skywalker18
User avatar
Retired Moderator
Joined: 08 Dec 2013
Last visit: 15 Nov 2023
Posts: 2,039
Own Kudos:
9,960
 [4]
Given Kudos: 171
Status:Greatness begins beyond your comfort zone
Location: India
Concentration: General Management, Strategy
GPA: 3.2
WE:Information Technology (Consulting)
Products:
My Reviews
Posts: 2,039
Kudos: 9,960
 [4]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 15 Dec 2017, 00:56
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
noboru
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpretation of certain footprints that were left among other footprints in hardened volcanic ash at site G. Dr. Tyson claims they are clearly early hominid footprints since they show human characteristics: a squarish heel and a big toe immediately adjacent to the next toe. However, since the footprints indicate that if hominids made those prints they would have had to walk in an unexpected cross-stepping manner, by placing the left foot to the right of the right foot. Dr. Rees rejects Dr. Tyson’s conclusion.

Which one of the following, if true, most seriously undermines Dr. Tyson’s conclusion?

(A) The foot prints showing human characteristics were clearly those of at least two distinct individuals.

(B) Certain species of bears had feet very like human feet, except that the outside toe on each foot was the biggest toe and the innermost toe was the smallest toe.

(C) Footprints shaped like a human’s that do not show a cross-stepping pattern exist at site M, which is a mile away from site G, and the two sets of footprints are contemporaneous.

(D) When the moist volcanic ash became sealed under additional layers of ash before hardening, some details of some of the footprints were erased.

(E) Most of the other footprints at site G were of animals with hooves.

Source: LSAT
Show more

the reason (D) is incorrect is that neither paleontologist weighs in on the issue of how much evidence you need to support a conclusion. That is, the disagreement is about what can be inferred from the evidence, not about whether there is enough evidence to draw any conclusion.

B-->, we have to make sure we understand the evidence brought up in the stimulus. It appears that the footprints discovered, though similar in shape to humans', differs in an important way: the "left" foot is on the right, and the "right" foot is on the left. As Dr. Rees says, for hominids to make those footprints, they would have to walk in a bizarre cross-stepping pattern.

Now if it turns out that a certain species of bear has footprints very similar to humans', except the order of the toes is reversed, then those bears would leave footprints just like the ones in question. (Look at your feet. If your big toe and little toe switched places, your right foot would look more like a left foot, and vice versa.) So if (B) is true, then it's much more likely that the footprints were left by bears than by early hominids, so Dr. Tyson's conclusion is weakened.
User avatar
gmatexam439
User avatar
Moderator
Joined: 28 Mar 2017
Last visit: 18 Oct 2024
Posts: 1,064
Own Kudos:
2,159
 [1]
Given Kudos: 200
Location: India
Concentration: Finance, Technology
Schools: McDonough '21 (A$) Jones '21 (A$) Kelley '23 (A)
GMAT 1: 730 Q49 V41
GPA: 4
Products:
My Reviews
Schools: McDonough '21 (A$) Jones '21 (A$) Kelley '23 (A)
GMAT 1: 730 Q49 V41
Posts: 1,064
Kudos: 2,159
 [1]
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 15 Dec 2017, 14:37
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpretation of certain footprints that were left among other footprints in hardened volcanic ash at site G. Dr. Tyson claims they are clearly early hominid footprints since they show human characteristics: a squarish heel and a big toe immediately adjacent to the next toe. However, since the footprints indicate that if hominids made those prints they would have had to walk in an unexpected cross-stepping manner, by placing the left foot to the right of the right foot. Dr. Rees rejects Dr. Tyson’s conclusion.

Which one of the following, if true, most seriously undermines Dr. Tyson’s conclusion?

(A) The foot prints showing human characteristics were clearly those of at least two distinct individuals. -This strengthens the argument on Tyson.

(B) Certain species of bears had feet very like human feet, except that the outside toe on each foot was the biggest toe and the innermost toe was the smallest toe. -Correct

(C) Footprints shaped like a human’s that do not show a cross-stepping pattern exist at site M, which is a mile away from site G, and the two sets of footprints are contemporaneous. -This slightly strengthens the argument

(D) When the moist volcanic ash became sealed under additional layers of ash before hardening, some details of some of the footprints were erased. -But, still from the pattern we can end up stating that the prints were of human. This doesn't exactly weaken the argument. B is better than this option

(E) Most of the other footprints at site G were of animals with hooves. -So?
User avatar
VerbalBot
User avatar
Non-Human User
Joined: 01 Oct 2013
Last visit: 04 Jan 2021
Posts: 18,835
Own Kudos:
986
Posts: 18,835
Kudos: 986
Two paleontologists, Dr Tyson and Dr. Rees, disagree over the interpre 30 Aug 2025, 09:53
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderators:
GMATNinja
GMAT Club Verbal Expert
7445 posts
GMATNinjaTwo
GMAT Club Verbal Expert
234 posts
miag
188 posts