The problems of evolution and its main aspects are discussed not only by biologists and geneticists but also by medical students and the public which is interested in the evolutionary issues. That is why the results of significant researches which were conducted by prominent scientists in the field of genetics and the problems of evolution require their further discussion and analysis in the form of critical articles and commentaries.
Thus, Joel Hagen, the professor of biology and the researcher of the questions connected with the history of biology, has presented his own vision of the issues which were described by the British ecological geneticist H. B. D. Kettlewell in his “Darwin’s Missing Evidence”. This research was published in Scientific American in 1959 as the result of the series of experiments and the continuation of the previous works.
In his article Joel Hagen has concentrated on a range of questions connected with the results of Kettlewell’s experiments which he determined as rather controversial. The conclusions of the article written by Kettlewell are considered as the “a convincing demonstration of natural selection at work” (Hagen 143). Nevertheless, the peculiarities of the research provided by Kettlewell were analyzed by Hagen from different sides.
Hagen states that “the ways in which the experiments are retold deviate significantly from Kettlewell’s original descriptions of his research” (Hagen 143). This aspect affected Hagen’s determining the main objectives of the article. The main aim of the article is to present the complete argument for the original claim “that many retrospective accounts present Kettlewell’s research as a controlled experiment” (Hagen 144).
There are also two sub-goals which can help to develop the detailed analysis of the work. Thus, Hagen also pays attention to the peculiarities of the discussion of Kettlewell’s experiments presented in the literature of evolutionary biology and in the field of science education. Moreover, Hagen focuses on the analysis of “Kettlewell’s role in retelling his early experiments on the peppered moths” (Hagen 144).
Hagen’s work is divided into several parts. The first part of the research presents the examination of the background to Kettlewell’s experiments. The author describes the features of the phenomenon known as the industrial melanism.
He discusses different approaches to the study and interpretation of this process and pays attention to the experiments with the peppered moth. Moreover, Hagen accentuates the peculiarities of the process’s explanation by Darwinian and non-Darwinian scientists. The peculiarities of the phenomenon’s study provided by such scientists as Haldane and Ford form the conceptual framework for Kettlewell’s researches.
The next parts of the article describe the peculiar features of the experiments and observations conducted by Kettlewell which became the base for the justification of his hypotheses. Hagen concentrates on mark-release-recapture experiments and the 1953 Birmingham study. According to these experiments, definite criteria for the study of the phenomenon were determined. Hagen offers the complete description of the principles of the experiments and their results.
He analyzes the data and approaches presented in different researches. He also compares them with the report of 1959. The comparison helps to define the main controversies in the researches which can influence the result of the work which is presented as a controlled experiment.
The controversies are also noticed in the early works. “Kettlewell’s early (1955) report presented the 1953 Birmingham study as a completed project rather than work-in-progress” (Hagen 147). Thus, while describing the peculiarities of the experiments, Hagen focuses on all the possible inaccuracies in the works.
Furthermore, Hagen analyzes the level of the impact of Kettlewell’s results on the other biologists’ opinions. The discussion of these problems is also based on the references to David Rudge’s vision of the issue. Hagen provides his analysis with many references to the works of this scientist.
However, the next parts of Hagen’s article describe the peculiarities of Ford’s discussion of the results of Kettlewell’s experiments. The main aspect of the discussion is the idea that “the natural selection is the cause of industrial melanism” and the features of its interpretation according to the consequences of Kettlewell’s experiments (Hagen 151). The commentary on Kettlewell’s researches provided by E. B. Ford is considered as the most influential for the biologists because E. B. Ford was the mentor of Kettlewell.
Hagen also pays attention to the significance of Kettlewell’s experiments and researches for the science and analyzes their main impacts. The last two parts of Hagen’s work are connected and discuss the peculiarities of popularizing Darwin’s missing evidence in the scientists’ world and its effects for the consideration of the problems of evolution in science education. “Darwin’s Missing Evidence” appeared at a critical time of reform in science education” (Hagen 152).
That is why the results of Kettlewell’s research and his idea that Darwin’s theory lacked the demonstration of natural selection in action attracted the public attention and arouse the reactions in the fields of biology and genetics.
In his article Hagen has accentuated the weak points and inaccuracies connected with Kettlewell’s experiments and the results of the research presented in his “Darwin’s Missing Evidence” and discussed these aspects from different viewpoints.
Works Cited
Hagen, Joel. “Retelling Experiments: H. B. D. Kettlewell’s Studies of Industrial Melanism in Peppered Moths”. Academic Reading: Reading and Writing in the Disciplines. Ed. Janet Giltrow. USA: Broadview Press, 2002. 143-158. Print.