Reconsider Mendel’s Principle of Heredity Based on the Logic of Experiment Design

Author Info
Bei-Chang Yang
Department of Microbiology & Immunology; Research Center for Society, Technology and Medicine of College of Medicine of National Cheng Kung University

Gregor Mendel used garden pea as experiment model to study the development of plant hybrids. His findings lead to three major conclusions that are coined as the fundamental laws of heredity: the law of dominance, the law of segregation, and the law of independent assortment. However, the significance of his findings has been neglected for 35 years. To explain this puzzle in science history, many efforts have been made by epistemological approaches including the evidence-based historiography and the Kuhnian paradigm-based historiography. They offered plausible pictures about the impact of Mendel’s discovery, but failed to provide a coherent strategy to avoid misinterpretation in science.

To compliment previous efforts, I try to re-interpret the story of Mendel’s discovery emphasizing the logic of experiment design. The major outline of Mendel’s paper was to document the transmission of phenotypes from parent to offspring. Choosing stable and convenient experiment materials, simplifying the observable target, and quantitatively analyzing the results, gave guarantee of Mendel’s success to reach the reliable conclusions. The techniques he used were commonly recognized among scientific community in those days. Hypothesizing the phenotype controlled by divisible “elements” is enough to draw a primitive but adequate theory that can be fully developed to classical genetic theory. However, the heredity unit firstly indicated by Mendel was only a vague concept without concrete quality. Thus, it serves no ground for any new research in breeding. Along with the progress of genetic science in twentieth century, chromosomes were identified as the Mendel’s heredity units. This lays the foundation for understanding the significance of Mendel’s work. This example highlights the usefulness of methodological materialism in the development of biology.


Taiwanese Journal for Studies of Science, Technology and Medicine, Number 10 (April 2010)