Historical study: Johann Gregor Mendel 1822-1884.

The life and personality of Johann Gregor Mendel (1822-1884), the founder of scientific genetics, are reviewed against the contemporary background of his times. At the end are weighed the benefits for Mendel (as charged by Sir Ronald Fisher) to have documented his results on hand of falsified data. Mendel was born into a humble farm family in the "Kuhländchen", then a predominantly German area of Northern Moravia. On the basis of great gifts Mendel was able to begin higher studies; however, he found himself in serious financial difficulties because of his father's accident and incapacitation. His hardships engendered illness which threatened continuation and completion of his studies until he was afforded the chance of absolving successfully theological studies as an Augustinian monk in the famous chapter of St. Thomas in Altbrünn (Staré Brno). Psychosomatic indisposition made Mendel unfit for practical pastoral duties. Thus, he was directed to teach but without appropriate state certification; an attempt to pass such an examination failed. At that point he was sent to the University of Vienna for a 2-year course of studies, with emphasis on physics and botany, to prepare him for the exam. His scientific and methodologic training enabled him to plan studies of the laws of inheritance, which had begun to interest him already during his theology training, and to choose the appropriate experimental plant. In 1865, after 12 years of systematic investigations on peas, he presented his results in the famous paper "Versuche über Pflanzenhybriden." Three years after his return from Vienna he failed to attain his teaching certification a second time. Only by virtue of his exceptional qualifications did he continue to function as a Supplementary Professor of Physics and Natural History in the two lowest classes of a secondary school. In 1868 he was elected Abbot of his chapter, and freed from teaching duties, was able to pursue his many scientific interests with greater efficiency. This included meteorology, the measurement of ground water levels, further hybridization in plants (a.o. involving the hawk week Hieracium up to about 1873), vegetable and fruit tree horticulture, apiculture, and agriculture in general. This involved Mendel's active participation in many organizations interested in advancing these fields at a time when appropriate research institutes did not exist in Brünn. Some of the positions he took in his capacity of Abbot had severe repercussions and further taxed Mendel's already over-stressed system. The worst of these was a 10-year confrontation with the government about the taxation of the monastery.(ABSTRACT TRUNCATED AT 400 WORDS)

[Not Available]. / Zur zeitlichen Datierung des genetischen "Notizblattes" Johann Gregor Mendels.

Mendel's record from his hybridiizing experiments comprising some calculations pertaining to the final trifactorial cross carried out with Pisum and concerning the varying intensity of the colour of the seedcoat is dated by July 1880 at the earliest. this means Mendel preoccupied himself with his genetical theory till the end of his life.

What about R.A. Fisher's statement of the "too good" data of J.G. Mendel's Pisum paper?

Mendel was accused by Fisher that his observed data, which corresponded to expectations, were too good to be true, and, further, that Mendel, growing only 10 plants per offspring, disregarded in his genotypical analysis the loss of recessives by assuming a ratio of 1:2 instead of 1.1126:1.8874. In contrast, it is proposed here that all chi-square statistics of genetic segregations fall short because the variance of genetic segregations is smaller and not of a binomial type as assumed. Furthermore, this variance and the corresponding chi-square statistics are not homogeneous in different segregation types. Consequently, it is not possible to summarize the different chi-square statistics as Fisher did. It is only in this way that he was able to obtain his unrealistic result (a probability of "seven times in 100,000 cases"). Regarding Fisher's second accusation, it should be taken into account that Mendel selected his 10 plants from offspring with a finite and not an infinite number of entities. Although this number is different from offspring to offspring, the average number is about 30. This means that the loss of recessives must be calculated by using a hypergeometric and not a binomial model as Fisher did. Consequently, the real deviation from the 1:2 ratio can be disregarded.

[F. C. NAPP andJ. G. MENDEL a contribution to the prehistory ofMENDEL's experiments]. / F. C. NAPP undJ. G. MENDEL Ein Beitrag zur Vorgeschichte derMENDELschen Versuche.

On the centenary of the death ofF. C. NAPP (22. 7. 1867), abbot of the St. Thomas-monastery of Old-Brünn, who admittedJ. G. MENDEL in his convent, enabled him to study natural science and to carry out his experiments, and on the centenary of the election ofMENDEL to succeedNAPP as abbot (31. 3. 1868), we take note of the relationship between these two men as it concerns the discoveries ofMENDEL. Following a short biography ofNAPP we appreciate his service to agriculture and its basic sciences. We find a close connection between the scientific work ofMENDEL andNAPP in meteorology and bee keeping.