Experiments on Plant Hybridization

Summary

"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 edit

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 edit

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 edit

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 edit

  The full text of Experiments in Plant-Hybridisation at Wikisource

References edit

  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.