Humorous jokes related to the phenomenon of separation

Loneliness, no ownership and piecemeal grinding into dust-Mendel and his genetic theory

1965 One evening in the summer, a grand commemorative meeting was held in a church in Brno Moravia, Czech Republic. Most people attending this commemorative meeting are not Christians, but geneticists from all over the world at the invitation of the Czech Academy of Sciences. With reverence and regret, they commemorate a great biologist who laid the foundation for genetics, and his achievements were buried for 35 years. He is Father gregor Mendel. 1965 is the centenary of the publication of his research results.

Mendel himself

Mendel (G.J.Mendel, 1822- 1884) was born in Heinshendorf village of Moyavia, Austria. Today, this place is Heinsis village in Czech Republic. Mendel's father is a farmer, and he likes growing flowers. Therefore, Mendel became interested in gardening from an early age. This may be the scientist's first chance to become famous in the pea experiment.

Mendel's childhood was not only ordinary, but also a little bitter. The whole primary school can be said to have gone through hunger and satiety. After graduating from high school, I mainly used my sister's dowry money to study philosophy at Omz College. After graduating from Mendel University at the age of 2/kloc-0, he became a monk at Augustine Monastery in Brown, Ehrt, and took a Christian name Grigo. Twenty-five years later, he was elected dean of the monastery.

If Mendel's childhood was spent in poverty, then Mendel, a young man, experienced the ups and downs of his life. Mendel was not satisfied with the monotonous life of monastery monks, and worked as a substitute teacher in an experimental school in Brno. He applied to be a full-time teacher twice, but both passed the exams in Sun Shan. What is particularly irritating is that in the second exam, the examiner commented on his test paper like this: "This test paper makes us feel that this student is not qualified to be a primary school teacher." During this period, he also attended the courses of plant physiology, mathematics and physics at Vienna University.

Mendel, who is studious and enterprising, failed in the exam and engaged in plant hybridization research in the monastery garden. Only a small part of his works has been published. In addition to the plant hybridization experiment that made him famous after his death (1865), there were artificial pollination of hibiscus hybrid (1870) and June cyclone 18+03 (18).

Mendel's later years can be said to be spent in gloomy clouds. He is alone, with no wife and no children, leaving him alone. He also reached an impasse with the authorities because he refused to pay the tax levied by the authorities on the temple. Academic ambition was not rewarded, and resentful and pretentious Mendel finally died of nephritis on June 6, 1984 at the age of 62. When people mourn for this poor young man, a man whose middle-aged research results were neglected and who was lonely and miserable in his later years, no one thought that he was a great scientist who left an outstanding chapter in the history of science.

Mendel's achievements

Mendel began to study plant hybridization, and the experimental material used was peas. He chose 22 pea varieties, according to the characteristics of round or shriveled seeds and yellow or green cotyledons. Pea is divided into 7 pairs of related characters. Then, according to a pair of relative traits and two pairs of relative traits, the following results were obtained.

Cross experiment of a pair of related characters Mendel crossed high pea and short pea by artificial pollination. The first generation hybrids (offspring 1) are all tall-stemmed. By self-pollination (self-pollination), he produced offspring from the hybrid of offspring 1. Results The second generation pea was 3/4 tall and 1/4 short, with a ratio of 3: 1. Mendel also carried out the above experiments on the other six pairs of relative traits, and as a result, the character separation ratio of 3: 1 was obtained in the second generation.

Cross experiment of two pairs of related traits Mendel made a cross experiment with two pairs of peas with related traits. The results showed that 1 took the place of yellow-wheel pea after crossing with green-wrinkled pea. Four types of seeds appeared in the second generation of self-pollination 1. Among 556 seeds, the ratio of yellow round, green round, yellow wrinkled and green wrinkled seeds is 9: 3: 3: 1.

Through the above experimental materials, Mendel skillfully deduced the following genetic principles.

1. separation phenomenon. Mendel assumed that the stem of tall pea was tall because it was controlled by the genetic factor (DD) of tall pea. Similarly, the dwarf of dwarf pea is also controlled by a dwarf genetic factor (dd). After hybridization, the factor of offspring 1 is Dd. Because D is a sexual factor and D is a recessive factor, all the descendants of 1 show tall stems. After selfing, the D and D of male and female gametes are randomly combined, so theoretically, the progeny 1 should have about the same number of four combination types: d D, dD, Dd. Because of the dominant and recessive relationship, the height-to-height ratio is 3: 1. According to these facts, Mendel came to the conclusion that although different genetic factors combine with each other in cells, they are independent and can be separated from each other, but not mixed with each other. Later generations called this discovery separation phenomenon.

2. The law of free combination. For tools

The hybridization of two peas with relative traits can also be explained by the above principle. If the factors of yellow round seeds are yy and rr, the factors of green wrinkled seeds are YY and RR. After two gametes cross, the offspring 1 is YyRr. Because y and r are dominant and y and r are recessive, the offspring 1 is yellow. After selfing, their offspring will have 16 individuals and 9 factor types. Because of the dominant and recessive relationship, there are four types in appearance: yellow circle, green circle, yellow wrinkle and green wrinkle, with a ratio of 9: 3: 3; 1。 Based on this, Mendel found that the combination of different genetic factors in plant hybridization obeys the law of permutation and combination, which is called the law of free combination by later generations.

Mendel's discovery was buried.

From 1856, Mendel got the above two laws, and after eight times of intensive research, he wrote a paper entitled "Experiment of Plant Hybridization". With the encouragement and support of his good friend Nessel (meteorologist), he reported this paper at the natural science research conference of Brno Society held on February 8 and March 8, 865/KLOC-0. Participants listened to his report with great interest, but probably didn't understand its contents. Because no one asked questions and no one discussed them. However, this paper was published in its own journal Journal of the Natural Science Research Society of Brno 1866.

People once thought that Mendel's work was buried because academic information was blocked and communication was not wide, and people didn't understand his work. After investigation, I realized that this was not the case. It turns out that there are at least 120 associations or societies to exchange information. A total of 1 15 magazines published in Mongolian were sent. Among them, local units 12, 8 in Berlin, 6 in Vienna, 4 in the United States and 2 in the United Kingdom (Royal Society and Linnaeus Society). Mendel himself sent a printed copy of the paper. Up to now, at least five people know his work. The first one is negri. He is a famous botanist in19th century. His research promoted the development of anatomy, physiology, taxonomy and evolution. In botany, he is an authority on the genus Cynanchum. Mendel not only sent his paper to him, but also wrote him a long letter to explain it further. The second is A. Cerna. He used to be a professor in Innsbruck and the director of Vienna Botanical Garden. The third is H. Hoffman, a professor of botany. The fourth is William Olbers Fogg, who is an authority on plant hybridization. The fifth place is Russian Schmalhausen. But publications and papers are like stones, and there is no obvious reaction. In this way, Mendel's epoch-making discovery laid the foundation of genetics, which was ignored and forgotten by contemporary people and buried for 35 years.

1900 is of great significance to Mendel's fame after his burial. This year, three people made Mendel's discovery almost at the same time. The first is the period of Defree, in which he published a paper with Mendel's discovery on March 26th, 1900. The second person is Collins, who received his paper on April 24th, 1900. The third person is Chu Schoemaker, who received his paper on June 20th 1900. It was in this year that they also found Mendel's paper. Only then did they realize that their work had been completed by Mendel 35 years ago.

Analysis of the reasons for Mendel's discovery being buried

There are many biological historians. I am very interested in this problem and have done some research. However, due to the long time, there are few materials with conclusive evidence, especially the living materials related to people's psychology are even more difficult to obtain. According to the existing materials, make the following analysis:

Limitations of history

When Mendel published his paper in 1866, it was the seventh year of Darwin's Origin of Species. During this period, biologists all over the world, especially famous biologists, turned their interest to the issue of biological evolution, and the issue of species hybridization naturally did not attract people's attention. This fact may have played a more decisive role in the fate of Mendel's work. Secondly, due to the limitation of historical conditions, academic materials could not be handed in widely at that time.

Traffic is also a reason. Darwin, for example, collected more information about hybridization, but never read Mendel's paper. Although some people say that even if Darwin saw this achievement, he may not fully realize its significance. However, there is not much basis for this inference. Another example is Schmalhausen, who knows Mendel's work in Russia. He initially added notes to the historical part of the paper and correctly evaluated Mendel's work. Unfortunately, when Flora published the translation of his paper in 1875, the comments added to evaluate Mendel's work were deleted. This reduces the chances for future generations to understand Mendel's work.

I suspect this is a new discovery. Mendel published his new discovery that he was just an ordinary monk. As for his research on plant hybridization, it is only regarded as "just for recreation, and his theory is just the nagging of an attractive lazy man." Indeed, in the eyes of a professional scholar, he is not a real biologist. Because he has neither a major in biology nor a title of doctor or professor. So his challenging discovery is naturally not easy to be believed. Judging from the reaction and attitude of a few people who have read his papers, it is an important reason to ignore Mendel's achievements and doubt or even believe that he can make any new discoveries. At that time, biologist negri knew Mendel best. Mendel has always been close to him and has been in contact with him for seven years. Mendel often exchanged seeds with him. He was also the first person to read Mongolian. However, it is precisely because he not only did not correctly understand Mendel's work, but also raised various questions and accusations, which became an important reason for this scientific disaster case that made future generations regret. It has been found that after reading Mendel's paper, he replied to Mendel at 1866 12 3 1. We can clearly see how he doubted, accused and even ignored Meng's work. He said in the letter: "I think your experiment with peas is far from complete, but this is just the beginning." ..... Such a group of experiments that can provide indisputable proof for the most important conclusion is by no means already under way. It's good that you plan to include other plants in your experiment. I believe you will get completely different results (in heredity) from other varieties. "He also doubts Mendel's law of 3: 1. For example, he said, "You should only regard quantitative expressions as empirical phenomena, because they cannot be proved to be reasonable. ".In negri's view," only those who can make correct judgments in the most vague professional fields can discuss this issue. "another A. Chelner, who knew Mendel's work, wrote back to Mendel after receiving the paper sent by Mendel. But according to Cerna's assistant, Mendel's paper has never been opened in the library of Cerna. Can people infer that in Cerna's eyes, an article written by a nobody like Mendel is simply contemptuous?

Don't understand the significance of its achievements.

Mendel's discovery itself, to some extent, surpassed the popular concept at that time. At that time, the traditional genetic view was fusion genetic theory, and Mendel's thought was particle inheritance; Secondly, at that time, the research methods in the field of biology were mainly qualitative observation and experiment, and Mendel adopted quantitative mathematical statistical analysis. Therefore, even if you read his article carefully, if you can't jump out of the traditional box, you may not understand its meaning. For example, H. Hoffman not only read his articles, but also quoted Mendel's articles in five places in his own works, but now it seems that he either didn't lead to important places or misunderstood them. In short, he didn't really understand the significance of Mendel's work. Therefore, in Hoffman's book, Mendel's contribution was completely ignored. Fogg also mentioned Mendel's achievements many times, but he said: "The results of many crosses made by Mendel are very similar to those of Knight, but Mendel thinks he has found a stable quantitative relationship among various types of crosses." What he denied was Mendel's success, which showed that he didn't understand the significance of Mendel's discovery at all. He mentioned Mendel, but because Mendel was bred into a plant hybrid, he had to mention it.

Lessons and enlightenment

Mendel has found this case for more than one hundred years. Today, Mendel's position and brilliant achievements in the history of science have been fully affirmed, and genetics based on his achievements has also won a brilliant victory. However, we should not forget that ignoring Mendel's discovery is costly and may delay the development of biology.

It has been delayed for decades. Shouldn't we learn from it and find out the enlightening truth from the past, so as not to make similar mistakes or less in the future?

Be wary of the shackles of traditional ideas

Some people think that Mendel's discovery is premature and beyond the level of understanding of the times, so it is inevitable to be buried. However, we believe that Mendel's discovery was not understood and buried, mainly because of the shackles of traditional concepts. The reason is that Mendel's topic has been put in front of people. At least some people's work is close to Mendel's conclusion (see History of Genetics, pages 126- 138 and 189), including the well-known Darwin, whose hybridization experiment on snapdragon is only a small step away from Mendel's conclusion. This fully shows that Mendel's discovery is not an accidental premature baby, but a mature historical condition. The reason why the above-mentioned people and those who have read Mendel's papers have not reached Mendel's conclusion and realized its significance is mainly because they have not broken through the shackles of traditional concepts and jumped out of the shackles of traditional qualitative methods. And Mendel's success, because of his less stereotypes, is likely to break through the popular research methods at that time.