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 ross 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?
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.
When the moist volcanic ash became sealed under additional layers of ash before hardening, some details of some of the footprints were erased.
What's wrong with my answer? I understand that TCR opens up the possibility that the bears, rather than humans, left the prints, but doesn't my answer open up the possibility that the prints were damaged, and were originally created by something else?
No, it doesn't. Some details were ERASED, not altered. Accordingly, what is left in the imprints in the hardened ash is the original footprints sans some details. You are stretching that answer to bridge the gap from some details erased to your thought that that can show they were created by something else.
How did you rationalize that leap / unwarranted assumption?
I conjured up an image of a talon mark that had been left by the footprint's original owner as part of the footprint. Then I imagined that talon mark had been erased by the sealing of the footprints by the additional layers of ash.
What's to prevent this hypothetical scenario from weakening the argument? TCR may be stronger, because it suggests a specific alternative cause of the footprint, but wouldn't this hypothetical weaken the argument as well? Is my hypothetical too much of a stretch, given the information presented?
I didn't quite mentally process the part of TCR that dealt with difference in big toe position when I originally read TCR, and so I chose the other answer choice that seemed plausible.