Experiments on Plant Hybridization

"Experiments on Plant Hybridization" (German: "Versuche über Pflanzen-Hybriden") is a seminal paper written in 1865 and published in 1866^[1][2] by Gregor Mendel, an Augustinian friar considered to be the founder of modern genetics. The paper was the result after years spent studying genetic traits in Pisum sativum, the pea plant.

Content

In his paper, Mendel compared 7 pairs of discrete traits found in a pea plant:

Characteristics	Contrasting traits	Offspring traits
Flower Color	Violet and White	Violet
Flower Position	Axial and Terminal	Axial
Plant Height	Tall and Dwarf	Tall
Seed Texture	Round and Wrinkled	Round
Seed Color	Green and Yellow	Yellow
Pea Pod Texture	Inflated and Constricted	Inflated
Pea Pod Color	Green and Yellow	Green

Through experimentation, Mendel discovered that one inheritable trait would invariably be dominant to its recessive alternative. Mendel laid out the genetic model later known as Mendelian inheritance or Mendelian genetics. This model provided an alternative to blending inheritance, which was the prevailing theory at the time.

History

Mendel read his paper to the Natural History Society of Brünn. It was published in the Proceedings of the Natural History Society of Brünn the following year.

Mendel's work received little attention from the scientific community and was largely forgotten. It was not until the early 20th century that Mendel's work was rediscovered and his ideas used to help form the modern synthesis.

Analysis

In 1936, the statistician Ronald Fisher used a Pearson's chi-squared test to analyze Mendel's data and concluded that Mendel's results with the predicted ratios were far too perfect, suggesting that adjustments (intentional or unconscious) had been made to the data to make the observations fit the hypothesis.^[3]

Later authors have suggested Fisher's analysis was flawed, proposing various statistical and botanical explanations for Mendel's numbers.^[4] It is also possible that Mendel's results are "too good" merely because he reported the best subset of his data—Mendel mentioned in his paper that the data were from a subset of his experiments.

External links

  The full text of Experiments in Plant-Hybridisation at Wikisource

References

1. Mendel, J. G. (1866). "Versuche über Pflanzenhybriden", Verhandlungen des naturforschenden Vereines in Brünn, Bd. IV für das Jahr, 1865, Abhandlungen: 3–47, [1]. For the English translation, see: Druery, C. T.; Bateson, William (1901). "Experiments in plant hybridization" (PDF). Journal of the Royal Horticultural Society. 26: 1–32. Retrieved 9 October 2009.
2. "Mendel's paper "Versuche über Pflanzenhybriden", was read at meetings of the Brunn Natural History Society on 8th February and 8th March 1865, and was published in the Verhandlungen des naturforschenden Vereines in Brünn, 4, 1865, which appeared in 1866" (Gregor Mendel, Experiments in Plant Hybridisation, Cosimo, Inc., 2008, p. 7).
3. Fisher, R. A. (1936). "Has Mendel's work been rediscovered?". Annals of Science. 1 (2): 115–126. doi:10.1080/00033793600200111. hdl:2440/15123.
4. Sturtevant, A. H. (2001). A History of Genetics. Cold Springs Harbor, New York: Cold Springs Harbor Laboratory Press. pp. 13–16. ISBN 0-87969-607-9.