Gregor Johann Mendel OSA (//; Czech: Řehoř Jan Mendel; 20 July 1822 – 6 January 1884) was a German-Czech biologist, meteorologist, mathematician, Augustinian friar and abbot of St. Thomas' Abbey in Brno (Brünn), Margraviate of Moravia. Mendel was born in a German-speaking family in the Silesian part of the Austrian Empire (today's Czech Republic) and gained posthumous recognition as the founder of the modern science of genetics. Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel's pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.
20 July 1822
|Died||6 January 1884 (aged 61)|
|Alma mater||University of Olomouc|
University of Vienna
|Known for||Founder of the modern science of genetics|
|Institutions||St Thomas's Abbey, Brno|
|Ordained||25 December 1846|
Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms "recessive" and "dominant" in reference to certain traits. In the preceding example, the green trait, which seems to have vanished in the first filial generation, is recessive and the yellow is dominant. He published his work in 1866, demonstrating the actions of invisible "factors"—now called genes—in predictably determining the traits of an organism.
The profound significance of Mendel's work was not recognized until the turn of the 20th century (more than three decades later) with the rediscovery of his laws. Erich von Tschermak, Hugo de Vries and Carl Correns independently verified several of Mendel's experimental findings in 1900, ushering in the modern age of genetics.
Early life and education
Mendel was born into a German-speaking family in Heinzendorf bei Odrau (called Hynčice in Czech), at the Moravian-Silesian border, Austrian Empire (now Czechia). He was the son of Anton and Rosine (Schwirtlich) Mendel and had one older sister, Veronika, and one younger, Theresia. They lived and worked on a farm which had been owned by the Mendel family for at least 130 years (the house where Mendel was born is now a museum devoted to Mendel). During his childhood, Mendel worked as a gardener and studied beekeeping. As a young man, he attended gymnasium in Troppau (Czech: Opava). He had to take four months off during his gymnasium studies due to illness. From 1840 to 1843, he studied practical and theoretical philosophy and physics at the Philosophical Institute of the University of Olomouc (German: Olmütz), taking another year off because of illness. He also struggled financially to pay for his studies, and Theresia gave him her dowry. Later he helped support her three sons, two of whom became doctors.
He became a monk in part because it enabled him to obtain an education without having to pay for it himself. As the son of a struggling farmer, the monastic life, in his words, spared him the "perpetual anxiety about a means of livelihood." Born Johann Mendel, he was given the name Gregor (Řehoř in Czech) when he joined the Order of Saint Augustine.
When Mendel entered the Faculty of Philosophy, the Department of Natural History and Agriculture was headed by Johann Karl Nestler who conducted extensive research of hereditary traits of plants and animals, especially sheep. Upon recommendation of his physics teacher Friedrich Franz, Mendel entered the Augustinian St Thomas's Abbey in Brno and began his training as a priest. Mendel worked as a substitute high school teacher. In 1850, he failed the oral part, the last of three parts, of his exams to become a certified high school teacher. In 1851, he was sent to the University of Vienna to study under the sponsorship of Abbot Cyril František Napp so that he could get more formal education. At Vienna, his professor of physics was Christian Doppler. Mendel returned to his abbey in 1853 as a teacher, principally of physics. In 1854 he met Aleksander Zawadzki who encouraged his research in Brno. In 1856, he took the exam to become a certified teacher and again failed the oral part. In 1867, he replaced Napp as abbot of the monastery.
After he was elevated as abbot in 1868, his scientific work largely ended, as Mendel became overburdened with administrative responsibilities, especially a dispute with the civil government over its attempt to impose special taxes on religious institutions. Mendel died on 6 January 1884, at the age of 61, in Brno, from chronic nephritis. Czech composer Leoš Janáček played the organ at his funeral. After his death, the succeeding abbot burned all papers in Mendel's collection, to mark an end to the disputes over taxation. The exhumation of Mendel's corpse in 2021 delivered some physiognomic details like body height (168 cm (66 in)). His genome was analysed, revealing that Mendel was predisposed to heart problems.
Experiments on plant hybridization
Mendel, known as the "father of modern genetics", chose to study variation in plants in his monastery's 2 hectares (4.9 acres) experimental garden. Mendel was assisted in his experimental design by Aleksander Zawadzki while his superior abbot Napp wrote to discourage him, saying that the Bishop giggled when informed of the detailed genealogies of peas.
After initial experiments with pea plants, Mendel settled on studying seven traits that seemed to be inherited independently of other traits: seed shape, flower color, seed coat tint, pod shape, unripe pod color, flower location, and plant height. He first focused on seed shape, which was either angular or round. Between 1856 and 1863 Mendel cultivated and tested some 28,000 plants, the majority of which were pea plants (Pisum sativum). This study showed that, when true-breeding different varieties were crossed to each other (e.g., tall plants fertilized by short plants), in the second generation, one in four pea plants had purebred recessive traits, two out of four were hybrids, and one out of four were purebred dominant. His experiments led him to make two generalizations, the Law of Segregation and the Law of Independent Assortment, which later came to be known as Mendel's Laws of Inheritance.
Initial reception of Mendel's work
Mendel presented his paper, Versuche über Pflanzenhybriden ("Experiments on Plant Hybridization"), at two meetings of the Natural History Society of Brno in Moravia on 8 February and 8 March 1865. It generated a few favorable reports in local newspapers, but was ignored by the scientific community. When Mendel's paper was published in 1866 in Verhandlungen des naturforschenden Vereines in Brünn, it was seen as essentially about hybridization rather than inheritance, had little impact, and was cited only about three times over the next thirty-five years. His paper was criticized at the time, but is now considered a seminal work. Notably, Charles Darwin was not aware of Mendel's paper, and it is envisaged that if he had been aware of it, genetics as it exists now might have taken hold much earlier. Mendel's scientific biography thus provides an example of the failure of obscure, highly original innovators to receive the attention they deserve.
Rediscovery of Mendel's work
About forty scientists listened to Mendel's two groundbreaking lectures, but it would appear that they failed to understand the implications of his work. Later, he also carried on a correspondence with Carl Nägeli, one of the leading biologists of the time, but Nägeli too failed to appreciate Mendel's discoveries. At times, Mendel must have entertained doubts about his work, but not always: "My time will come," he reportedly told a friend, Gustav von Niessl.
During Mendel's lifetime, most biologists held the idea that all characteristics were passed to the next generation through blending inheritance (indeed, many effectively are), in which the traits from each parent are averaged. Instances of this phenomenon are now explained by the action of multiple genes with quantitative effects. Charles Darwin tried unsuccessfully to explain inheritance through a theory of pangenesis. It was not until the early 20th century that the importance of Mendel's ideas was realized.
By 1900, research aimed at finding a successful theory of discontinuous inheritance rather than blending inheritance led to independent duplication of his work by Hugo de Vries and Carl Correns, and the rediscovery of Mendel's writings and laws. Both acknowledged Mendel's priority, and it is thought probable that de Vries did not understand the results he had found until after reading Mendel. Though Erich von Tschermak was originally also credited with rediscovery, this is no longer accepted because he did not understand Mendel's laws. Though de Vries later lost interest in Mendelism, other biologists started to establish modern genetics as a science. All three of these researchers, each from a different country, published their rediscovery of Mendel's work within a two-month span in the spring of 1900.
Mendel's results were quickly replicated, and genetic linkage quickly worked out. Biologists flocked to the theory; even though it was not yet applicable to many phenomena, it sought to give a genotypic understanding of heredity which they felt was lacking in previous studies of heredity, which had focused on phenotypic approaches. Most prominent of these previous approaches was the biometric school of Karl Pearson and W. F. R. Weldon, which was based heavily on statistical studies of phenotype variation. The strongest opposition to this school came from William Bateson, who perhaps did the most in the early days of publicising the benefits of Mendel's theory (the word "genetics", and much of the discipline's other terminology, originated with Bateson). This debate between the biometricians and the Mendelians was extremely vigorous in the first two decades of the 20th century, with the biometricians claiming statistical and mathematical rigor, whereas the Mendelians claimed a better understanding of biology. Modern genetics shows that Mendelian heredity is in fact an inherently biological process, though not all genes of Mendel's experiments are yet understood.
In the end, the two approaches were combined, especially by work conducted by R. A. Fisher as early as 1918. The combination, in the 1930s and 1940s, of Mendelian genetics with Darwin's theory of natural selection resulted in the modern synthesis of evolutionary biology.
Mendel began his studies on heredity using mice. He was at St. Thomas's Abbey but his bishop did not like one of his friars studying animal sex, so Mendel switched to plants. Mendel also bred bees in a bee house that was built for him, using bee hives that he designed. He also studied astronomy and meteorology, founding the 'Austrian Meteorological Society' in 1865. The majority of his published works were related to meteorology.
Mendel also experimented with hawkweed (Hieracium) and honeybees. He published a report on his work with hawkweed, a group of plants of great interest to scientists at the time because of their diversity. However, the results of Mendel's inheritance study in hawkweeds was unlike his results for peas; the first generation was very variable and many of their offspring were identical to the maternal parent. In his correspondence with Carl Nägeli he discussed his results but was unable to explain them. It was not appreciated until the end of the nineteenth century that many hawkweed species were apomictic, producing most of their seeds through an asexual process.
None of his results on bees survived, except for a passing mention in the reports of Moravian Apiculture Society. All that is known definitely is that he used Cyprian and Carniolan bees, which were particularly aggressive to the annoyance of other monks and visitors of the monastery such that he was asked to get rid of them. Mendel, on the other hand, was fond of his bees, and referred to them as "my dearest little animals".
In 1936, Ronald Fisher, a prominent statistician and population geneticist, reconstructed Mendel's experiments, analyzed results from the F2 (second filial) generation and found the ratio of dominant to recessive phenotypes (e.g. yellow versus green peas; round versus wrinkled peas) to be implausibly and consistently too close to the expected ratio of 3 to 1. Fisher asserted that "the data of most, if not all, of the experiments have been falsified so as to agree closely with Mendel's expectations". Mendel's alleged observations, according to Fisher, were "abominable", "shocking", and "cooked".
Other scholars agree with Fisher that Mendel's various observations come uncomfortably close to Mendel's expectations. A. W. F. Edwards, for instance, remarks: "One can applaud the lucky gambler; but when he is lucky again tomorrow, and the next day, and the following day, one is entitled to become a little suspicious". Three other lines of evidence likewise lend support to the assertion that Mendel's results are indeed too good to be true.
Fisher's analysis gave rise to the Mendelian paradox: Mendel's reported data are, statistically speaking, too good to be true, yet "everything we know about Mendel suggests that he was unlikely to engage in either deliberate fraud or in unconscious adjustment of his observations". A number of writers have attempted to resolve this paradox.
One attempted explanation invokes confirmation bias. Fisher accused Mendel's experiments as "biased strongly in the direction of agreement with expectation [...] to give the theory the benefit of doubt". In a 2004 article, J.W. Porteous concluded that Mendel's observations were indeed implausible. An explanation for Mendel's results based on tetrad pollen has been proposed, but reproduction of the experiments showed no evidence that the tetrad-pollen model explains any of the bias.
Another attempt to resolve the Mendelian paradox notes that a conflict may sometimes arise between the moral imperative of a bias-free recounting of one's factual observations and the even more important imperative of advancing scientific knowledge. Mendel might have felt compelled "to simplify his data in order to meet real, or feared, editorial objections". Such an action could be justified on moral grounds (and hence provide a resolution to the Mendelian paradox), since the alternative—refusing to comply—might have retarded the growth of scientific knowledge. Similarly, like so many other obscure innovators of science, Mendel, a little known innovator of working-class background, had to "break through the cognitive paradigms and social prejudices" of his audience. If such a breakthrough "could be best achieved by deliberately omitting some observations from his report and adjusting others to make them more palatable to his audience, such actions could be justified on moral grounds".
Daniel L. Hartl and Daniel J. Fairbanks reject outright Fisher's statistical argument, suggesting that Fisher incorrectly interpreted Mendel's experiments. They find it likely that Mendel scored more than 10 progeny, and that the results matched the expectation. They conclude: "Fisher's allegation of deliberate falsification can finally be put to rest, because on closer analysis it has proved to be unsupported by convincing evidence". In 2008 Hartl and Fairbanks (with Allan Franklin and AWF Edwards) wrote a comprehensive book in which they concluded that there were no reasons to assert Mendel fabricated his results, nor that Fisher deliberately tried to diminish Mendel's legacy. Reassessment of Fisher's statistical analysis, according to these authors, also disproves the notion of confirmation bias in Mendel's results.
Mount Mendel in New Zealand's Paparoa Range was named after him in 1970 by the Department of Scientific and Industrial Research. In celebration of his 200th birthday, Mendel's body was exhumed and his DNA sequenced.
- Fr. Richter, Clemens OSA (2015). "Remembering Johann Gregor Mendel: a human, a Catholic priest, an Augustinian monk, and abbot". Molecular Genetics & Genomic Medicine. 3 (6): 483–485. doi:10.1002/mgg3.186. PMC 4694133. PMID 26740939.
- Funeral card in Czech (Brno, 6. January 1884)
- 20 July is his birthday; often mentioned is 22 July, the date of his baptism. Biography of Mendel at the Mendel Museum Archived 10 April 2019 at the Wayback Machine
- Czech J. Genet. Plant Breed., 50, 2014 (2): 43–51
- Klein, Jan; Klein, Norman (2013). Solitude of a Humble Genius – Gregor Johann Mendel. Volume 1, Formative years. Berlin: Springer. pp. 91–103. ISBN 978-3-642-35254-6. OCLC 857364787.
- Schacherer, Joseph (2016). "Beyond the simplicity of Mendelian inheritance". Comptes Rendus Biologies. 339 (7–8): 284–288. doi:10.1016/j.crvi.2016.04.006. PMID 27344551.
- Gayon, Jean (2016). "From Mendel to epigenetics: History of genetics". Comptes Rendus Biologies. 339 (7–8): 225–230. doi:10.1016/j.crvi.2016.05.009. PMID 27263362.
- Corcos, Alain F.; Monaghan, Floyd V. (1990). "Mendel's work and its rediscovery: A new perspective". Critical Reviews in Plant Sciences. 9 (3): 197–212. doi:10.1080/07352689009382287.
- Gregor Mendel, Alain F. Corcos, Floyd V. Monaghan, Maria C. Weber "Gregor Mendel's Experiments on Plant Hybrids: A Guided Study", Rutgers University Press, 1993.
- "Úvod – Rodný dům Johanna Gregora Mendela".
- Camarena, Belia (20 March 2018). "Gregor Mendel, the Father of Modern Genetics: Brilliant Scientist or Complete Failure?". StMU Research Scholars. Retrieved 10 March 2023.
- Eckert-Wagner, Silvia (2004). Mendel und seine Erben: Eine Spurensuche [Mendel and His Heirs: A search for traces] (in German). Norderstedt: Books on Demand. p. 113. ISBN 978-3-8334-1706-1.
- Henig, Robin Marantz (2000). The Monk in the Garden: The Lost and Found Genius of Gregor Mendel, the Father of Genetics. Boston: Houghton Mifflin. pp. 19–21. ISBN 0-395-97765-7. OCLC 43648512.
- Iltis, Hugo (1943). "Gregor Mendel and His Work". The Scientific Monthly. 56 (5): 414–423. Bibcode:1943SciMo..56..414I. JSTOR 17803.
- Henig 2000, p. 24.
- Hasan, Heather (2004). Mendel and The Laws Of Genetics. The Rosen Publishing Group. ISBN 978-1-4042-0309-9.
- Fisher, R. A. (1933). "The Mathematics of Inheritance". Online Museum Exhibition. The Masaryk University Mendel Museum. 132 (3348): 1012. Bibcode:1933Natur.132.1012F. doi:10.1038/1321012a0.
- Henig 2000, pp. 47–62.
- "Online Museum Exhibition". The Masaryk University Mendel Museum. Archived from the original on 21 October 2014. Retrieved 20 January 2010.
- Windle, B.C.A. (1911). "Mendel, Mendelism". Catholic Encyclopedia. Looby, John (trans.). Retrieved 2 April 2007.
- Carlson, Elof Axel (2004). "Doubts about Mendel's integrity are exaggerated". Mendel's Legacy. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press. pp. 48–49. ISBN 978-0-87969-675-7.
- Austria Presse Agentur. "Genomanalyse beim ersten Genetiker: Gregor Mendel exhumiert". science.apa.at (in German). Retrieved 16 July 2022.
- "Mendel's Experiments on Peas". The Masaryk University Mendel Museum. Archived from the original on 9 August 2021. Retrieved 4 October 2020.
- Szybalski, W. (2010). "Professor Alexander Zawadzki of Lvov university – Gregor Mendel's mentor and inspirer". Biopolymers and Cell. 26 (2): 83–86. doi:10.7124/bc.000149.
- Henig 2000, pp. 78–80.
- Magner, Lois N. (2002). History of the Life Sciences (3, revised ed.). New York: Marcel Dekker. p. 380. ISBN 978-0-203-91100-6.
- Gros, Franc̜ois (1992). The Gene Civilization (English Language ed.). New York: McGraw Hill. p. 28. ISBN 978-0-07-024963-9.
- Moore, Randy (2001). "The "Rediscovery" of Mendel's Work" (PDF). Bioscene. 27 (2): 13–24. Archived from the original (PDF) on 16 February 2016.
- Butler, John M. (2010). Fundamentals of Forensic DNA Typing. Burlington, MA: Elsevier/Academic Press. pp. 34–35. ISBN 978-0-08-096176-7.
- Henig 2000, pp. 134–138.
- Mendel, J.G. (1866). "Versuche über Pflanzenhybriden", Verhandlungen des naturforschenden Vereines in Brünn, Bd. IV für das Jahr, 1865, Abhandlungen: 3–47. 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. Archived (PDF) from the original on 2 September 2000. Retrieved 9 October 2009.
- Galton, D. J. (2011). "Did Mendel falsify his data?". QJM. 105 (2): 215–16. doi:10.1093/qjmed/hcr195. PMID 22006558.
- Lorenzano, P (2011). "What would have happened if Darwin had known Mendel (or Mendel's work)?". History and Philosophy of the Life Sciences. 33 (1): 3–49. PMID 21789954.
- Liu, Y (2005). "Darwin and Mendel: who was the pioneer of genetics?". Rivista di Biologia. 98 (2): 305–22. PMID 16180199.
- Nissani, M. (1995). "The Plight of the Obscure Innovator in Science". Social Studies of Science. 25 (1): 165–83. doi:10.1177/030631295025001008. S2CID 144949936.
- Gustafsson, A. (1969). "The life of Gregor Johann Mendel--tragic or not?". Hereditas. 62 (1): 239–258. doi:10.1111/j.1601-5223.1969.tb02232.x. PMID 4922561.
- Weldon, W. F. R. (1902). "Mendel's Laws of Alternative Inheritance in Peas". Biometrika. 1 (2): 228–233. doi:10.1093/biomet/1.2.228.
- Bulmer, Michael (1999). "The Development of Francis Galton's Ideas on the Mechanism of Heredity". Journal of the History of Biology. 32 (2): 263–292. doi:10.1023/A:1004608217247. PMID 11624207. S2CID 10451997.
- Mayr E. (1982). The Growth of Biological Thought. Cambridge: The Belknap Press of Harvard University Press. p. 730. ISBN 978-0-674-36446-2.
- Henig 2000, pp. 1–9.
- Carlson, Elof Axel (2004). Mendel's Legacy: The Origins of Classical Genetics. New York: Cold Spring Harbor.
- Deichmann, Ute (2011). "Early 20th-century research at the interfaces of genetics, development, and evolution: Reflections on progress and dead ends". Developmental Biology. 357 (1): 3–12. doi:10.1016/j.ydbio.2011.02.020. PMID 21392502.
- Elston, RC; Thompson, EA (2000). "A century of biometrical genetics". Biometrics. 56 (3): 659–66. doi:10.1111/j.0006-341x.2000.00659.x. PMID 10985200. S2CID 45142547.
- Pilpel, Avital (September 2007). "Statistics is not enough: revisiting Ronald A. Fisher's critique (1936) of Mendel's experimental results (1866)". Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences. 38 (3): 618–26. doi:10.1016/j.shpsc.2007.06.009. PMID 17893069.
- Reid, J. B.; Ross, J. J. (2011). "Mendel's genes: toward a full molecular characterization". Genetics. 189 (1): 3–10. doi:10.1534/genetics.111.132118. PMC 3176118. PMID 21908742.
- Ellis, T.H. Noel; Hofer, Julie M.I.; Timmerman-Vaughan, Gail M.; Coyne, Clarice J.; Hellens, Roger P. (2011). "Mendel, 150 years on". Trends in Plant Science. 16 (11): 590–96. doi:10.1016/j.tplants.2011.06.006. PMID 21775188.
- Kutschera, Ulrich; Niklas, KarlJ. (2004). "The modern theory of biological evolution: an expanded synthesis". Naturwissenschaften. 91 (6): 255–76. Bibcode:2004NW.....91..255K. doi:10.1007/s00114-004-0515-y. PMID 15241603. S2CID 10731711.
- Hall, Brian Keith; Hallgrímsson, Benedikt; Strickberger, Monroe W. (2014). Strickberger's evolution (5 ed.). Burlington, Mass.: Jones & Bartlett Learning. pp. 10–11. ISBN 978-1-4496-1484-3.
- Henig 2000, pp. 15–17.
- "The Enigma of Generation and the Rise of the Cell". The Masaryk University Mendel Museum. Archived from the original on 21 October 2014. Retrieved 20 January 2010.
- Vecerek, O. (1965). "Johann Gregor Mendel as a Beekeeper". Bee World. 46 (3): 86–96. doi:10.1080/0005772X.1965.11095345. ISSN 0005-772X.
- Nogler, GA (2006). "The lesser-known Mendel: his experiments on Hieracium". Genetics. 172 (1): 1–6. doi:10.1093/genetics/172.1.1. PMC 1456139. PMID 16443600.
- Mendel, Gregor (1869). "Ueber einige aus künstlicher Befruchtung gewonnenen Hieracium-Bastarde. (On Hieracium hybrids obtained by artificial fertilisation)". Verh. Naturf. Ver. Brünn. 8 (Abhandlungen): 26–31.
- Koltunow, A. M. G.; Johnson, S. D.; Okada, T. (2011). "Apomixis in hawkweed: Mendel's experimental nemesis". Journal of Experimental Botany. 62 (5): 1699–1707. doi:10.1093/jxb/err011. PMID 21335438.
- Orel, Vítězslav; Rozman, Josef; Veselý, Vladimír (1965). Mendel as a Beekeeper. Moravian Museum. pp. 12–14.
- Demerec, M. (1956). Advances in Genetics. New York: Academic Press. p. 110. ISBN 978-0-08-056795-2.
- Roberts, Michael; Ingram, Neil (2001). Biology (2 ed.). Cheltenham: Nelson Thornes. p. 277. ISBN 978-0-7487-6238-5.
- Matalova, A; Kabelka, A (1982). "The beehouse of Gregor Mendel". Casopis Moravskeho Musea. Acta Musei Moraviae – Vedy Prirodni. Car Morav Mus Acta Mus Vedy Prir. 57: 207–12.
- "Index of Botanists: Mendel, Gregor Johann". HUH – Databases – Botanist Search. Harvard University Herbaria & Libraries. Retrieved 29 January 2018.
- Fisher, R.A. (1936). "Has Mendel's work been rediscovered?" (PDF). Annals of Science. 1 (2): 115–37. doi:10.1080/00033793600200111. hdl:2440/15123. Archived (PDF) from the original on 13 April 2011.
- Thompson, EA (1990). "R.A. Fisher's contributions to genetical statistics". Biometrics. 46 (4): 905–14. doi:10.2307/2532436. JSTOR 2532436. PMID 2085639.
- Pilgrim, I (1984). "The too-good-to-be-true paradox and Gregor Mendel". The Journal of Heredity. 75 (6): 501–02. doi:10.1093/oxfordjournals.jhered.a109998. PMID 6392413.
- Hartl, Daniel L.; Fairbanks, Daniel J. (2007). "Mud sticks: On the alleged falsification of Mendel's Data". Genetics. 175 (3): 975–79. doi:10.1093/genetics/175.3.975. PMC 1840063. PMID 17384156.
- Piegorsch, WW (1990). "Fisher's contributions to genetics and heredity, with special emphasis on the Gregor Mendel controversy". Biometrics. 46 (4): 915–24. doi:10.2307/2532437. JSTOR 2532437. PMID 2085640.
- Edwards, A. W. F. (1986). "More on the too-good-to-be-true paradox and Gregor Mendel". Journal of Heredity. 77 (2): 138. doi:10.1093/oxfordjournals.jhered.a110192.
- Nissani, M. (1994). "Psychological, Historical, and Ethical Reflections on the Mendelian Paradox". Perspectives in Biology and Medicine. 37 (2): 182–96. doi:10.1353/pbm.1994.0027. PMID 11644519. S2CID 33124822.
- Price, Michael (2010). "Sins against science: Data fabrication and other forms of scientific misconduct may be more prevalent than you think". Monitor on Psychology. 41 (7): 44.
- Porteous, JW (2004). "We still fail to account for Mendel's observations". Theoretical Biology & Medical Modelling. 1: 4. doi:10.1186/1742-4682-1-4. PMC 516238. PMID 15312231.
- Fairbanks, D. J.; Schaalje, G. B. (2007). "The tetrad-pollen model fails to explain the bias in Mendel's pea (Pisum sativum) experiments". Genetics. 177 (4): 2531–34. doi:10.1534/genetics.107.079970. PMC 2219470. PMID 18073445.
- Novitski, Charles E. (2004). "On Fisher's criticism of Mendel's results with the garden pea". Genetics. 166 (3): 1133–36. doi:10.1534/genetics.166.3.1133. PMC 1470775. PMID 15082533. Retrieved 20 March 2010.
In conclusion, Fisher's criticism of Mendel's data—that Mendel was obtaining data too close to false expectations in the two sets of experiments involving the determination of segregation ratios—is undoubtedly unfounded.
- Franklin, Allan; Edwards, AWF; Fairbanks, Daniel J; Hartl, Daniel L (2008). Ending the Mendel-Fisher controversy. Pittsburgh, PA: University of Pittsburgh Press. p. 67. ISBN 978-0-8229-4319-8.
- Monaghan, F; Corcos, A (1985). "Chi-square and Mendel's experiments: where's the bias?". The Journal of Heredity. 76 (4): 307–09. doi:10.1093/oxfordjournals.jhered.a110099. PMID 4031468.
- Novitski, C. E. (2004). "Revision of Fisher's analysis of Mendel's garden pea experiments". Genetics. 166 (3): 1139–40. doi:10.1534/genetics.166.3.1139. PMC 1470784. PMID 15082535.
- "Place name detail: Mount Mendel". New Zealand Gazetteer. New Zealand Geographic Board. Retrieved 21 August 2022.
- Why scientists dug up the father of genetics, Gregor Mendel, and analyzed his DNA
- William Bateson Mendel, Gregor; Bateson, William (2009). Mendel's Principles of Heredity: A Defence, with a Translation of Mendel's Original Papers on Hybridisation (Cambridge Library Collection – Life Sciences). Cambridge, UK: Cambridge University Press. ISBN 978-1-108-00613-2. On-line Facsimile Edition: Electronic Scholarly Publishing, Prepared by Robert Robbins
- Hugo Iltis, Gregor Johann Mendel. Leben, Werk und Wirkung. Berlin: J. Springer. 426 pages. (1924)
- Translated by Eden and Cedar Paul as Life of Mendel. New York: W. W. Norton & Co, 1932. 336 pages. New York: Hafner, 1966: London: George Allen & Unwin, 1966. Ann Arbor: University Microfilms International, 1976.
- Translated by Zhenyao Tan as Mên-tê-êrh chuan. Shanghai: Shang wu yin shu guan, 1924. 2 vols. in 1, 661 pp. Shanghai: Shang wu yin shu guan, Minguo 25 .
- Translated as Zasshu shokubutsu no kenkyū. Tsuketari Menderu shōden. Tōkyō: Iwanami Shoten, Shōwa 3 . 100 pp. Translated by Yuzuru Nagashima as Menderu no shōgai. Tōkyō: Sōgensha, Shōwa 17 . Menderu den. Tōkyō: Tōkyō Sōgensha, 1960.
- Klein, Jan; Klein, Norman (2013). Solitude of a Humble Genius – Gregor Johann Mendel: Volume 1. Heidelberg: Springer. ISBN 978-3-642-35253-9.
- Robert Lock, Recent Progress in the Study of Variation, Heredity and Evolution, London, 1906
- Orel, Vítĕzslav (1996). Gregor Mendel: the first geneticist. Oxford [Oxfordshire]: Oxford University Press. ISBN 978-0-19-854774-7.
- Punnett, Reginald Crundall (1922). Mendelism. London: Macmillan. (1st Pub. 1905)
- Curt Stern and Sherwood ER (1966) The Origin of Genetics.
- Taylor, Monica (July–September 1922). "Abbot Mendel". Dublin Review. London: W. Spooner.
- Tudge, Colin (2000). In Mendel's footnotes: an introduction to the science and technologies of genes and genetics from the nineteenth century to the twenty-second. London: Vintage. ISBN 978-0-09-928875-6.
- Waerden, B. L. V. D. (1968). "Mendel's Experiments". Centaurus. 12 (4): 275–88. Bibcode:1968Cent...12..275V. doi:10.1111/j.1600-0498.1968.tb00098.x. PMID 4880928. refutes allegations about "data smoothing"
- James Walsh, Catholic Churchmen in Science, Philadelphia: Dolphin Press, 1906
- Windle, Bertram C. A. (1915). "Mendel and His Theory of Heredity". A Century of Scientific Thought and Other Essays. Burns & Oates.
- Zumkeller, Adolar; Hartmann, Arnulf (1971). "Recently Discovered Sermon Sketches of Gregor Mendel". Folia Mendeliana. 6: 247–52.
- Works by Gregor Mendel at Project Gutenberg
- Works by or about Gregor Mendel at Internet Archive
- Works by Gregor Mendel at LibriVox (public domain audiobooks)
- 1913 Catholic Encyclopedia entry, "Mendel, Mendelism"
- Augustinian Abbey of St. Thomas at Brno
- Biography, bibliography and access to digital sources in the Virtual Laboratory of the Max Planck Institute for the History of Science
- Biography of Gregor Mendel
- GCSE student
- Gregor Mendel (1822–1884)
- Gregor Mendel Primary Sources
- Johann Gregor Mendel: Why his discoveries were ignored for 35 (72) years (in German)
- Masaryk University to rebuild Mendel’s greenhouse | Brno Now
- Mendel Museum of Genetics
- Mendel's Paper in English
- Online Mendelian Inheritance in Man
- A photographic tour of St. Thomas' Abbey, Brno, Czech Republic