Chapter 31 Section 2 Understanding of Biological Genetic Variation

As early as the Zhou Dynasty, people had clearly recognized that there were differences among biological breeds. "Zhou Li" already mentioned horses with various variations, such as stallion horses, military horses, Dao horses, field horses, and rough horses. "Erya" even recorded 36 horse breeds and their differences.Wang Chong clearly talked about biological variation in "Lunheng".When he refuted the world's superstition about the so-called "auspicious things" such as phoenix, unicorn and Jiahe in "Lunheng·Guorui", he pointed out that phoenix, unicorn and Jiahe are not special or mysterious species of creatures, but ordinary beasts. Variations of species or birds and cereal crops (grasses).He said: "All auspicious things are born from harmony, born among ordinary people, but have a strange nature." He also gave many examples to illustrate the variation of creatures.He said: "The more often white pheasants are presented, the white pheasants are born with white ears, so there is no species of white pheasants." This means that white pheasants, like common pheasants, are not a special species, but their coat color has turned white.For Jiahe, known as "Ruiwu", Wang Chong believes that it is still a variation of ordinary grain ears.He said: "Jiahe is born in the grass, and it is different from the ears of the grass." This clearly points out that the so-called "Jiahe" is derived from ordinary grains. Compared with ordinary grains, it is only different in ears.In the ancient books of our country, there are many records about the discovery of branch variation of cereal crops.For example, according to the "Book of Later Han Guangwu Benji", Jiahe was found in Jiyang (now Yi County, Shandong Province) in the first year of Jianping in the Western Han Dynasty (6 BC), with one stem and nine ears.Another example is that according to "Liang Shu · Wudi Benji", in May of the fourth year of Liang Tianjian (AD 505), a stalk of Jiahe with 12 ears was found in Shuoyinli, Jiankang County (south of Jiangning County, Jiangsu Province).There are so many examples of this.It can be seen that the ancients were deeply impressed by the branching variation of cereal crops such as rice and wheat.

In the literature of the past dynasties, there are many records about biological variation.Jia Sixie said in "Qi Min Yao Shu Planting the Grain": "There are sooner or later when the grain matures, the height of the seedling stalk, the size of the harvest, the strength of the quality, the good or bad of the taste of rice, and the depletion of the grain. Jia Sixie not only pointed out the difference in the maturity period of grains, but also pointed out the variation of various other traits.Cai Xiang of the Song Dynasty pointed out in the book "Lychee Spectrum" (AD 1059): "Litchi is sweet, although there are hundreds of trees, there is no one like it." Liu Meng wrote in "Ju Pu" (AD 1104) 35 species of chrysanthemum have been described.When talking about the variation of chrysanthemums, he said: "The ones with big flowers are chamomile, and the ones with small and bitter flowers are wild chrysanthemums. If you plant fertile garden vegetables, they will become one. Small can become big, and bitter can change." It is sweet. If so, then the single leaf will change into a thousand leaves, and there are also some." Song Yingxing in the Ming Dynasty said in "Tiangong Kaiwu": "There are many types of millet, and the distance between hundreds of miles, the color, taste, shape, and quality It changes accordingly, similar with minor differences, and has thousands of names." These fully reflect that the ancients had a certain understanding of the universality of biological variation. "Similar with minor differences" correctly reflects the general situation of biological variation in nature. The offspring of the parents are both like the parents and different from the parents. "The distance is hundreds of miles. The color, taste, shape and quality will change accordingly." It can be seen that Song Yingxing also believes that the variation of living things is closely related to the changes in the living environment of living things.

In the production practice of ancient people, it was often found that environmental changes lead to biological mutations.When Jia Sixie talked about growing garlic in "Qi Min Yao Shu", he pointed out that small tiles should be placed on the bottom of the ridge, and single-clove garlic should be placed on the tiles, and then covered with soil.The garlic grown in this way has a very special shape, flat, wide and large.Jia Sixie was very surprised by this, saying that this "is enough to make a difference".Jia Sixie also talked about this fact.It is said that there was no garlic in Shanxi (Bingzhou) at that time, and people all went to Henan (Chaoge) to get garlic seeds.But after taking garlic and planting it for a year, it turned into white garlic again, and the garlic petals were very small.On the contrary, the turnip roots in Shanxi are as big as the mouth of a bowl. Even turnip seeds taken from other places will grow bigger as long as they are planted for a year.Jia Sixie sighed: "Garlic petals become smaller, turnip roots become larger, and the two things are opposite, so it's hard to reason." Also, peas from Shanxi are planted east of Jingxingkou, and millet from Shandong is planted in pots in Shanxi. If the party is closed, it will be too long and not fruitful.Jia Sixie said that these were not just rumors, but what he "saw with his own eyes".In the end, he concluded that, in short, these are all caused by different land conditions.Agronomists and horticulturalists of all ages have almost the same opinion.

Shen Kuo in the Song Dynasty said in "Mengxi Bi Tan": "Zhuyue has peaches and plums in winter, and Shuomo has peaches and plums in Xiarong. This place is full of energy." Yuan Dynasty Wang Zhen's "Nongshu" said: "Everything has its own species. It is suitable, so those suitable for Hebei and Yan are not suitable for Qing and Xu, and those suitable for Jing and Yang are not suitable for Yong and Yu... The quality of valleys is different, and the climate is suitable for each." The ancients saw, Organisms will mutate in different environments, so it is correct that there are organisms that adapt to different environments.

There are genetic variations and non-inherited variations.As early as the Han Dynasty, people realized that some mutations were not inherited.Wang Chong pointed out that the so-called "Jiahe" is a non-inherited variation.He said, "Try to sow the fruit of Jiahe, but you will not get Jiahe", which shows that he has experimented. In practice, many variations have also been found to be heritable.Ouyang Xiu in the Song Dynasty mentioned many examples of peony mutations in "Luoyang Peony", and pointed out that these mutations are heritable.