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.
The author's stance toward the arguments of the strict constructionist Darwinians can most accurately be described as one of
emphatic disagreement
Supported. The author strongly disagrees with the constructionists. She says that there are “numerous examples” undermining their view, and she spends P3 and P4 giving evidence for why they’re wrong.
mild disapproval
Unsupported— too weak. The author doesn’t just mildly disapprove of the constructionists’ view; she strongly disagrees with it. The main point of the passage is to criticize the constructionists, and she spends P3 and P4 providing evidence that undermines their view.
open-minded neutrality
Anti-supported. The author is not open-minded or neutral toward the constructionists’ view; she strongly disagrees with it. The main point of the passage is to criticize the constructionists, and she spends P3 and P4 providing evidence that undermines their view.
conditional agreement
Anti-supported. The author does not agree with the constructionists’ view; she strongly disagrees with it. The main point of the passage is to criticize the constructionists, and she spends P3 and P4 providing evidence that undermines their view.
unreserved endorsement
Anti-supported. The author does not endorse with the constructionists’ view; she strongly disagrees with it. The main point of the passage is to criticize the constructionists, and she spends P3 and P4 providing evidence that undermines their view.
Answer five questions and we'll estimate your score.
It takes about five minutes.
Take the free diagnostic