A recent study has provided clues to predator-prey dynamics in the late Pleistocene era.
Researchers compared the number of tooth fractures in present-day carnivores with tooth fractures
in carnivores that lived 36,000 to 10,000 years ago and that were preserved in the Rancho La Brea
tar pits in Los Angeles. The breakage frequencies in the extinct species were strikingly higher than
those in the present-day species.
In considering possible explanations for this finding, the researchers dismissed demographic bias
because older individuals were not overrepresented in the fossil samples. They rejected
preservational bias because a total absence of breakage in two extinct species demonstrated that
the fractures were not the result of abrasion within the pits. They ruled out local bias because
breakage data obtained from other Pleistocene sites were similar to the La Brea data. The
explanation they consider most plausible is behavioral differences between extinct and present-day
carnivores-in particular, more contact between the teeth of predators and the bones of prey due to
more thorough consumption of carcasses by the extinct species. Such thorough carcass
consumption implies to the researchers either that prey availability was low, at least seasonally, or
that there was intense competition over kills and a high rate of carcass theft due to relatively high
predator densities.
231. The primary purpose of the passage is to
(A) present several explanations for a well-known fact
(B) suggest alternative method of resolving a debate
(C) argue in favor of a controversial theory
(D) question the methodology used in a study
(E) discuss the implications of a research finding
I chose the answer (A) considering the several possible explanations studied by the researcher, however there was only one plausible explanation.
OA is (E). Can someone explain why the OA is (E)?![]()
Researchers compared the number of tooth fractures in present-day carnivores with tooth fractures
in carnivores that lived 36,000 to 10,000 years ago and that were preserved in the Rancho La Brea
tar pits in Los Angeles. The breakage frequencies in the extinct species were strikingly higher than
those in the present-day species.
In considering possible explanations for this finding, the researchers dismissed demographic bias
because older individuals were not overrepresented in the fossil samples. They rejected
preservational bias because a total absence of breakage in two extinct species demonstrated that
the fractures were not the result of abrasion within the pits. They ruled out local bias because
breakage data obtained from other Pleistocene sites were similar to the La Brea data. The
explanation they consider most plausible is behavioral differences between extinct and present-day
carnivores-in particular, more contact between the teeth of predators and the bones of prey due to
more thorough consumption of carcasses by the extinct species. Such thorough carcass
consumption implies to the researchers either that prey availability was low, at least seasonally, or
that there was intense competition over kills and a high rate of carcass theft due to relatively high
predator densities.
231. The primary purpose of the passage is to
(A) present several explanations for a well-known fact
(B) suggest alternative method of resolving a debate
(C) argue in favor of a controversial theory
(D) question the methodology used in a study
(E) discuss the implications of a research finding
I chose the answer (A) considering the several possible explanations studied by the researcher, however there was only one plausible explanation.
OA is (E). Can someone explain why the OA is (E)?