Charles Darwin objected to all attempts to reduce his theory of evolution to its doctrine of natural selection. "Natural selection has been the main but not the exclusive means of modification," he declared. …
Natural selection is generally held to result in adaptation, the shaping of an organism's form and behavior in response to environmental conditions to achieve enhanced reproductive success. …
For example, while it is true that some random mutations of genetic material produce attributes that enhance reproductive success and are thus favored by natural selection, and others produce harmful attributes that are weeded out, we now know from population genetics that most mutations fall into neither category. Research has revealed that neutral, nonadaptive changes account to a large extent for the evolution of DNA. Most substitutions of one unit of DNA for another within a population have no effect on reproductive success. These alterations often change the attributes of species, but their persistence from one generation to the next is not explainable by natural selection.
Additionally, the study of mass extinctions in paleontology has undermined the strict constructionist claim that natural selection can account for every species' success or failure. The extinction of the dinosaurs some 65 million years ago was probably caused by the impact of an extraterrestrial body. Smaller animal species are generally better able to survive the catastrophic changes in climate that we would expect to follow from such an impact, and mammals in the Cretaceous period were quite small because they could not compete on the large scale of the dominant dinosaurs. But while this scenario explains why dinosaurs died off and mammals fared relatively well, it does not conform to the strict constructionist view of the adaptive reasons for the success of species. For that view assumes that adaptations are a response to conditions that are already in place at the time the adaptations occur, and mammals could not have adapted in advance to conditions caused by the impact. In a sense, their success was the result of dumb luck.
Which one of the following most accurately and completely describes the function of the second paragraph of the passage?
It outlines the objections to traditional evolutionary theory raised by the strict constructionists mentioned in the first paragraph.
The passage doesn’t mention “traditional evolutionary theory.” The strict constructionists disagree with Darwin, since they reduce evolution to natural selection, but we don’t know whether this is in conflict with “traditional evolutionary theory.” Regardless, P2 doesn’t outline the constructionists’ objections to anything.
It lists recent evidence suggesting that the strict constructionist claims described in the first paragraph are incorrect.
P3 describes research suggesting that the strict constructionists are wrong. But P2 describes an implication of the strict constructionists’ view and then suggests that their view is incorrect.
It describes the strict constructionists' view of evolutionary theory in order to explain why the evidence described in subsequent paragraphs has recently gotten so much attention.
P2 points out an implication of the strict constructionists’ view, but the author does this in order to introduce her main point— that the strict constructionists are wrong. We have no idea whether the evidence in P3 and P4 has gotten much attention or not.
It enumerates the arguments for the strict constructionist position that are rebutted in the paragraphs that follow.
The strict constructionists’ view is that natural selection explains all biological phenomena, and the author does refute this in P3 and P4. But she never enumerates the arguments for their view. That is, we don’t know why the constructionists believe this. Instead, P2 describes and refutes an implication of their view.
It explains the ramifications of the strict constructionists' claims and helps clarify the relevance of evidence offered in subsequent paragraphs.
P2 explains
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