✪ Chen Xi | Institute of Historical Geography, Fudan University
【Introduction】Ancient people's cloud: "No filial piety has three, no queen is greater", and the continuation of "incense" is the most important belief in traditional Chinese society. But to what extent has this ideal been realized in reality?
Based on genealogical data, this paper examines and determines the gap between the ideal and reality of continuing incense: although the succession of generations is the universal ideal of people, and people have made various efforts, in reality, the ideal situation of children and grandchildren that people yearn for is rare, on the contrary, the extinction is a more universal reality.
The study found that among the many factors that affect heirs, the impact of the number of children is the most direct, and under the same mortality rate, the more children are born, the greater the chance of heirs. The number of children born is ultimately subject to socio-economic conditions, and people who occupy more resources have an advantage, and this advantage is gradually accumulated and magnified, so that their descendants gradually occupy the main part of the population. The vulnerable population, which accounts for the majority of the population, is gradually excluded and eliminated, and eventually eliminated. As the scale of the descendants of the dominant family continues to expand, there are also advantages and disadvantages among internal members, only a few descendants can inherit the advantages, and the majority gradually degenerates, and a new round of survival competition for the survival of the fittest is also unfolding.
The study pointed out that the proportion of unmarried heirs is higher than that of heiress, which is an important reason for the succession of heirs, but at the same time, there is no difference between the number and structure of wives and heirs, in other words, polygamy does not significantly improve the chances of heirs. Studies have shown that the purpose of childbearing in traditional societies is heirs, and if there are enough sons, people may end the act of procreation early. The fact that the number of wives has no significant effect on heirs also shows that in traditional societies where males dominate reproductive behavior, women's reproductive potential is largely idle.
This article was originally published in Southern Population, No. 6, 2012, originally titled "The Ideal of Continuing Incense and the Reality of Universal Extinction- Population Data Based on Genealogy", which only represents the author's point of view and is for the consideration of all kings.
The ideal of perpetuating incense and the reality of universal extinction – demographic data based on genealogy
▍ Introduction
"There are three filial pieties, and no queen is greater." Mencius's words typically reflect the strong desire and ethical requirements of traditional society for family continuation, and passing on the generations has become the most important mission in life. Fei Xiaotong once pointed out that the concept of continuing "incense" is the most important belief in Chinese society. However, there is little empirical evidence of the extent to which this ideal can be realized in reality. After the Ming and Qing dynasties, a large number of genealogies were compiled, which clearly recorded the reproduction process of the family population, including the birth and death years and kinship relationships of individuals, which provided the most effective information for studying the problem of population reproduction and incense continuation.
Although the population of the Qing Dynasty experienced explosive growth, from 160 million in the eighteenth year of the Kangxi Dynasty (1679) to 436 million in the second year of Xuan unification (1910), the mortality rate of the population remained high, the life expectancy was also very low, and the reproduction of the population was still in a traditional state of high birth and death, and the birth expectancy may be less than 30 years. According to the results of studies based on genealogical data, the average life expectancy of fifteen-year-old men in the 18th century was only 35-38 years. According to Liaoning household registration data, Li Zhongqing and others found that the life expectancy of the male population in the 1-5 age group in the Qing Dynasty was 35.9 years, and the female population was 29 years old. By the 1920s, the life expectancy of China's rural population at birth was only 24.2 years. According to Cole Deman's model life table, with a birth expectancy of 30 years, 40% of people will die before the age of 10 and 50% will die before the age of 20, which means that nearly half of the people die before entering the marriage state, unable to complete the mission of inheritance.
Infant and young child mortality in the Qing Dynasty was difficult to estimate, but overall it was at a high level during the period. Due to the relatively complete registration of daughters and children who died prematurely in the Royal Family Genealogy of the Qing Dynasty, Li Zhongqing and others have shown that the mortality rate of infants and young children in the Qing Dynasty was 100-400 ‰. Among rural children (1-5 years old) in Liaoning between 1774 and 1873, the mortality rate was 316 per thousand for girls and 266 per thousand for boys. After the Republic of China, regional population surveys increased, and in the 1930s, Xu Shilian estimated that the infant and young child mortality rate was around 250 per thousand. In the early 1940s, the infant mortality rate in Chenggong was 212.1 per thousand for men and 211.1 per thousand for women.
Early marriage is considered to be an important feature of China's historical population, but some recent studies have shown that only women marry early, while many men marry at the age of 30 or 40, and more than 5% of men are even unmarried for life, affected by high mortality rates, and the possibility of widowhood is high, which will have a negative impact on procreation.
Existing historical demography studies have shown that although the specific values are different, in the Qing Dynasty and even in the Republic of China, the mortality rate of Chinese population was at a very high level, especially infant and young child mortality, and the life expectancy of the population was short. In the face of high mortality, the difficulty of heirs is greatly increased, and there is a clear conflict between the ideal of perpetuating incense and the high mortality rate of the population.
The two macro-level characteristics of the rapid growth of the total population and the extremely low life expectancy of the Qing Dynasty seem to act on the reproduction of the micro family population at the same time. By looking at the genealogical chart of the family tree, it is easy to see that some branches of the family have a large number of descendants, and the population is rapidly increasing, while some branches are sparsely populated and gradually extinct. The chances of population reproduction are not evenly distributed among the various branches. At the same time as the rapid growth of the total population, the phenomenon of extinction is common, these two seemingly contradictory phenomena, let us put forward the hypothesis that the large population of the late Qing Dynasty may only be the descendants of a small number of people in the early Qing Dynasty, and the vast majority of the 160 million people in the early Qing Dynasty have been extinct for more than two hundred years. This means that the ideal of heirs may be difficult for most people to achieve, and only a few people can have their own offspring.
This paper uses genealogical data to conduct historical demography research, trying to test and determine the gap between the ideal and reality of continuing incense through genealogical data, and on this basis, the law of population reproduction is considered.
▍ Literature review
For the study of China's historical population, genealogy is one of the important data for quantitative analysis. As a kind of long-term population record, genealogy is usually recorded for hundreds of years or even thousands of years, which is suitable for long-term population analysis. Unlike the data recorded in the Zhengshi and Fang Zhi, since the family tree belongs to the private practice of the people, the main purpose of the family tree is to show the prosperity and longevity of the family, unlike the official population data, the family tree does not deliberately conceal the need to hide the family population. In addition, unlike the macro demographics in official records, genealogies are based on individual-level records, including individual births, deaths, and other information, which can be collated into a database to obtain statistical indicators suitable for demographic analysis. Since the 1970s and 1980s, family trees have gradually become the core data for the study of micropopulation behavior in Chinese history.
However, as with other historical demographical sources, genealogies have their own shortcomings, the most important of which is the omission of daughters and prematurely deceased children, as well as the underestimation and representation of mortality due to omissions, i.e. genealogies may reflect more of the population of families that have successfully multiplied and may not necessarily represent the entire population. Because of these missing issues, special caution is required when drawing conclusions using genealogical data. Although imperfect, genealogy is still an important data for the study of China's historical population, using CAMSIM method to compare micro population simulations with genealogical data to prove that many demographic indicators provided by genealogy are reliable, and reasonable and accurate population information can still be obtained from genealogical data with caution in these missing problems.
Since the 1980s, the use of genealogy for historical demography research has formed many important results, and there has been in-depth research on Chinese the mortality rate, marriage rate and fertility rate of the population since the Ming and Qing dynasties, especially the population in the past two hundred years; Family structure is also an important issue, but because genealogy cannot directly provide data on family size, scholars who study family trees can only explore family issues from the perspective of the constraints of population conditions on family structure. The constraints of population conditions on families are mainly manifested in the fact that the shorter average life expectancy limits the realization of large families. Due to the short life expectancy, it is difficult to achieve multi-generational cohabitation, making the nuclear family the mainstream family model. These studies delve into many aspects of historical population, while relatively few have examined aspects of the continuation of families themselves. Early studies of traditional Chinese clans by Freeman and others showed that the socioeconomic status of members within the family was differentiated, including both wealthy merchants and downtrodden poor people; both gentry with meritorious and prominent status, and peasants at the bottom of society. This means that the distribution of wealth and social prestige within the family is uneven, concentrated in specific branches of strength that accumulate and amplify over the process of reproduction. Through a study of three families in Xiaoshan, Zhejiang, Harrell demonstrated that the wealthy branches with more fame disproportionately account for most of the population.
John C.H. Fei et al. examine the development of the population of ten families and find that there is a CMV in the growth of the family population, that is, when the family population grows to the highest point, the family inevitably disintegrates, which may be attributed to the competition caused by the shortage of land resources in a specific area. Therefore, the family that initially had the advantage, with the increase of the family population size, the family advantage was unevenly distributed between different branches, which made the differentiation of the dominant and inferior branches within the family, and a new round of rich and poor differentiation began within the family, deducing the survival competition between similar families.
▍ Genealogical data and methods
This paper uses the Songyuan Wei Genealogy for analysis. Songyuan Town is located in the northwest mountainous area of Fujian Province, the terrain is relatively closed, belongs to the river valley basin, and is less affected by the outside world. The Wei genealogy was first compiled in the eighth year of Zhengde in the Ming Dynasty (1513), and has been added successively, and the fifth revision was carried out in the sixth year of the Republic of China (1917). Continuous revision can reduce the fallacy caused by long time and vague memory of ancestral information, and improve the accuracy of the record. Genealogically relevant records are genealogical tables, including the man's lineage, paternity, rank, position, merit, date of birth, date of death, date of birth of wife, date of death, names and number of sons and daughters, and early death and stepchildren. In addition, the genealogical genealogy diagram details the intergenerational inheritance relationship within the family, which is convenient for examining the intergenerational reproduction process of the family population. Inevitably, there are also problems with omissions in the Wei family tree, such as incomplete information about daughters, often only the number of daughters is recorded but not the birth and death years of daughters; There are omissions in the records of children who died early, often only the number of sons who died early, and there are almost no records of daughters who died early. However, the focus of this article is not on estimating the mortality rate of the population, so the impact of omissions in daughters and prematurely deceased children will be relatively small. In addition, another advantage of the Wei clan is that due to its relatively closed geographical location, it has been very little affected by wars in history, and events such as the Taiping Heavenly Kingdom War that caused major population losses in history have had little impact on the region.
Unlike previous studies, the study units in this paper are branch veins, not individuals or families. This article focuses on the inheritance of the entire family, that is, the continuation and demise of the family. A practical difficulty in research is that in history, some families have successfully multiplied, the size of the family has continued to grow, while some families have failed to reproduce and are headed for extinction, and those families that can compile the family tree belong to the successful reproduction, and the families that have never had heirs in history have appeared in history, but there is no family tree to pass down, so it is impossible to analyze their population situation. Fortunately, even within a successful family, the reproduction of each branch is different, and while some branches multiply and grow, others in the family gradually disappear. Competition for survival between families also exists between different branches within the family. However, information about the losers within successful families is kept relatively completely in the family tree, making it possible to reconstruct the historical scenes of competition between different branches in the process of reproduction.
Based on this assumption, this paper sets the 20th in the Wei genealogy as the 1st generation at the beginning of the breeding competition. There are a total of 169 males in the 20th generation, with their descendants as their respective descendants, assuming that they each become a separate family, so that 169 virtual branches can be obtained as the basic research unit of this article. The earliest birth time in the 20th century was the seventh year of Qing Shunzhi (1650), as the start time of observation; The year 1917 was the fifth revision of the score, as the end of time. From this, we can observe the reproduction and demise of these 169 branches, a total of 1360 males, during this 267 years.
▍ Branch reproduction competition
From 1650 to 1917, the entire Wei family gradually expanded. Between 1650 and 1770, the number of new males per twenty years in the family gradually increased from the initial 16 to about 100, and after 1770 the number of new males per twenty years stabilized at 80-100.
However, although the number of new males is steadily increasing, the distribution of the new population among the various branches is extremely uneven. In the beginning of the competition set in this article in 1650, these 169 branches all have only one man, and the starting point is fair; But after the competition began, some of the branches flourished and the population gradually increased, while some branches gradually became extinct. With each generation, a certain number of branches are eliminated (see Figure 1).
Figure 1 Survival rate of Songyuan Wei's branch
After experiencing the first generation of reproduction, the Songyuan Wei clan eliminated 43.8% of the branches, that is, more than 40% of the branches were extinct; By the second generation, 62.13% of the branches were eliminated, and the third generation eliminated 71.60%, which shows that within three generations, most of the branches of the Songyuan Wei clan have been cut off, and the speed of the branches being eliminated is very fast. After that, due to the small total number of surviving branches, the rate of extinction gradually slows down. Most of the branches that can reproduce for 5 generations have become the large branches of the Wei family. Continuing the incense becomes relatively easy for these large sticks. By the time of the last observation, 1917, 86.39% of the initial 169 branches had been extinct. This means that after 267 years of breeding competition, only 13.61% of people can have their own offspring.
The above analysis results are similar to the results of Zhao Zhongwei's microscopic population simulation experiment using CAMSIM method. In Zhao Zhongwei's experiment, after 9 generations of reproduction, only 398 people had their own descendants, and the proportion of heirs was only 13.27%. Because each family population has a certain particularity, the above data can not be directly generalized to other populations, but can reflect the general trend of population reproduction, that is, the difficulty of heirs is very large, the phenomenon of heirs is widespread, and the mission of succession is difficult for most people to complete.
Throughout the reproductive process, the Wei family produced a total of 1360 males, and these 1360 males were not evenly distributed among the various branches.
Table 1 Number of people contained in each branch
As can be seen from the cumulative percentage column of Table 1, 74.56% of the branches that are about to nearly 3/4 have only 5 people and less, and these sparse branches are very likely to face extinction; Only 7.69% of the branches, which can reach more than 26 people, belong to the victors in the process of reproduction. A few dominant branches occupy a large part of the population, while most of the inferior branches account for a small proportion of the population. The distribution of the population among the various branches is seriously imbalanced.
The Gini coefficient of these 1360 males distributed in 169 branches is 0.719, which shows that the distribution of the population is very uneven. This depicts for us a side of the competition for population reproduction, that is, a small number of dominant branches gradually prosper, appear to grow asymmetrically, occupy a large number of populations, and crowd out the development of other branches, while a large number of other inferior branches gradually go extinct.
The prosperity of the dominant branch and the elimination of the inferior branch is a cyclical process, when the number of descendants of the original dominant branch continues to increase, and its internal differentiation also begins, some can inherit the advantages of the predecessors, while some weaken, so the beginning of a new round of advantage elimination of disadvantages the process is repeated.
▍Influencing factors of heirs
Theoretically, there are many factors that affect whether a branch can pass on or not, but the explanatory factors that family trees can provide mainly include the following aspects: the number of children born, the number of wives, socio-economic status indicators (whether they are patriarchs and whether they have meritorious names), the number of prematurely deceased children, and succession. Since the value of the dependent variable is a binary variable between the heir and the heir, logistic regression analysis is used, and the results are shown in Table 2.
Table 2 Logistic regression analysis affecting extinction factors
(1) The number of children born
The number of children born is the most direct factor affecting the succession of heirs. Under the same health conditions and nutritional levels, the greater the number of children, the greater the chances of heirs. In the regression model 1, only the influence of the two variables of the number of sons and the number of daughters is considered, and the results show that both have a significant positive effect on improving the probability of heirs, and after adding other variables such as position, meritorious name, and number of prematurely deceased children in model 2 and 3, the influencing factors of the two variables of son number and daughter number have not weakened, which shows that the size of their influence is stable.
Figure 2 Lorentz curve of male population distribution between various branches
It should be noted that the coefficient of the number of daughters is significantly greater than the number of sons, which is caused by the incomplete record of daughters in the family tree, which does not mean that it is easier to have daughters. In all records, each man had an average of 1.1 sons and 0.3 daughters, indicating that there were serious omissions in the daughters. More importantly, over time, the number of records of her daughter has increased. Table 3 shows the number of sons and daughters born to fathers with recorded birth years (70.15 per cent of the total), where the year refers to the year in which the father was born. After 1750, the records of daughters gradually increased, and a large number of branches of the heirs had withdrawn from the historical stage in 1650-1750, which led to the majority of daughters appearing in the branches of the heirs, and there were few records of daughters in the branches of the heirs, which in turn caused the anomaly that the coefficient of influence of the number of daughters in the regression equation was greater than that of sons.
Table 3 Number of sons and daughters recorded in the family tree
(ii) Number of wives
It is generally believed that the more wives (including concubines and continuations), the more sons and daughters will be born, thereby increasing the probability of heirs, but this hypothesis is not supported by regression equations, such as regression model 2. Considering that the recordal bias of daughters and the number of daughters are theoretically the same as the number of sons contributing to heirs, the variable of daughter number is removed in model 2, and only the influence of the number of sons and wives is considered. The influence of the variable of wives on heirs showed a weak negative effect, but failed the significance test, and after the socio-economic variables were added to model 3, the number of wives still failed to pass the test.
Further comparisons of the marital status of married men in the extinct branch and the heir branch show no significant difference between the two. As shown in Table 4, both married heirs and heiress are mainly married to 1 wife, accounting for more than 80% of the total; The proportion of both wives is still high, reaching more than 10 per cent, and the proportion of polygamous wives is very low. Table 4 shows that there is no difference between the number and structure of wives between the heiress and the heiress.
Table 4 Number of wives married by extinct and heiress
It should be noted that the proportion of unmarried men who have no heirs is higher than that of heirs men, which is also an important reason for the extinction of heirs. The significance of comparing the marital status of married extinct and heiress is to show that once a man enters the marital state, the number of wives married does not affect the succession. Unmarried or unmarried certainly means the extinction of heirs, but polygamy does not significantly increase the chances of heirs. In married men, the correlation coefficient between the number of wives and the number of sons born was only 0.075, and the correlation was weak, which further indicated that the number of wives was not related to the number of sons, and polygamy did not lead to more children. Since the number of wives is rarely omitted, and the son's record is relatively complete, this conclusion has good credibility. Studies have shown that in traditional societies, the purpose of people giving birth is to pass on heirs, and if there are enough sons, then people may end the act of childbearing early. The fact that the number of wives has no significant effect on heirs also suggests that in traditional societies where males dominate reproductive behavior, women's reproductive potential is largely idle.
(3) Socio-economic status
Those who have the upper hand in marriage and reproduction are largely due to their higher socio-economic status. Those in the family who have meritorious names are able to marry and have children earlier, which makes it easier for them to obtain heirs, so to speak, "the rich have offspring". Studies of Britain's pre-Industrial Revolution population found a clear correlation between wealth status and the number of heirs, with the richest leaving twice as many offspring as the poorest. Poverty delays the age of marriage for men and becomes the leading cause of unmarried men over the age of 35. In the 18th and 19th centuries, only 6% of the sons of the upper nobility were unmarried between the ages of 30 and 40, while the proportion of singles among the lower nobility reached 12%, while in Tongcheng, Anhui, only 5% of the sons of the gentry class were over 20 years old and unmarried, and 15% of the sons of the non-gentry class were single. The poor are in a disadvantageous position in the marriage market, the increase in the proportion of unmarried women naturally increases the probability of extinction, and late marriage also compresses the reproductive period of both husband and wife, and in the era of low average life expectancy, the impact of the shortening of the fertility period on the number of children is obvious. In addition, malnutrition caused by poverty has reduced fertility, which has led to the fact that the rich tend to have more children in pre-modern societies.
In addition to influencing marriage rates, socioeconomic factors can also influence people's reproductive decisions and behaviors. Previous studies have shown that the fertility behavior of the traditional Chinese population is artificially controlled, not in a purely "natural state", people will carry out birth control according to the family economic situation and expectations for the future, and when people have enough sons to ensure the number of heirs, they may stop childbearing to reduce the economic burden. Delaying childbearing after marriage, ending the childbearing age early, and prolonging the birth spacing are the three population mechanisms that form low fertility. As a result, poverty may affect people's decisions and expectations about childbearing, reduce the number of children, and increase the likelihood of drowning. In addition, wealthy families can provide better living conditions and medical conditions for their members, and reduce mortality during famine years.
In genealogical data, there are few direct records of an individual's income status, so it is necessary to look for other proxy indicators. This article selects "patriarch" to represent the economic situation and "meritorious name" to represent social status. The patriarch is the authoritative representative of the entire family, and the branch of the patriarch often has more resources, thereby improving the chances of marriage, for example, in rural Liaoning, the probability of marriage of the patriarch is three times higher than that of ordinary people; Meritorious name is an important indicator of social status, with the meritorious name given by the state, not only can enjoy the material subsidies of the state, but also enjoy a certain social status and prestige at the local level. On the one hand, the examination of meritorious names requires a certain economic basis, although there are many examples of poor people obtaining meritorious names, but usually only families with better economic conditions can afford to support their descendants to study and obtain meritorious titles; On the other hand, many meritorious names are donated with money, and the more meritorious names are donated, the more they are donated, which also reflects the family's financial resources. In the model 3 of Table 2, the influence of the patriarch variable is very large and passes the significance test; Although the function name variable does not pass the test, the effect of the variable on the heir is also positive. Further chi-square analysis shows that among those with meritorious names, the proportion of heirs is much higher than that of heirs; Among those without merit, this gap is much smaller (see Table 5). The chi-square coefficient between the name of the meritorious name and the heir is 32.836 (p=0.000), which shows that the influence of whether the meritorious name has on whether or not to have offspring is significant.
Table 5 Cross-checks of whether there are names and descendants
Studies of the socioeconomic status variables represented by patriarchs and meritorious names have once again validated the conclusion of previous research that economically dominant populations are more likely to have offspring. This advantage is spread and inherited among close relatives, so that the advantage is further expanded, and the branch in turn gradually prospers and grows.
(4) Succession
Succession is a common method used in traditional societies to maintain the continuation of family incense. Succession includes two aspects: succession and succession. The factor of succession is not placed here in the regression equation, mainly because both the succession and the succession contain both positive and negative meanings for the continuation of the incense. As far as the succession is concerned, on the one hand, the succession can make up for the lack of male offspring and help to continue the incense, but on the other hand, the need to enter the succession itself also indicates that the branch is weak and almost broke the incense. Therefore, the succession factor has a positive and negative contradictory role in the continuation of offspring, and it is not convenient to enter the equation directly. Table 6 provides statistics on the movement of succession in the family.
Table 6 Number of heirs and proportion of heirs in the Wei family
If the "no-successor" group is the average, the proportion of heirs in the "succession 1 son" group is slightly lower than the average, indicating that the succession has played a role in continuing the incense to a certain extent; For those who have a successor to a son, the proportion of heirs is significantly higher than the average, indicating that the succession is not conducive to heirs. In fact, most of the time it is the sons of those with lower grades who pass on to those with higher grades, such as the sons of younger brothers who pass on to their older brothers. This means that to some extent, family status will also affect the occurrence of extinction.
In addition to the above factors, the number of prematurely deceased children is theoretically one of the influencing factors. Although it is difficult to estimate the level of child mortality due to serious omissions in the genealogy of children, we found 77 records of children who died prematurely. In the regression equation, the factors of prematurely deceased children barely pass the test and show a negative impact on heirs, i.e., the probability of heirs may decrease as the number of children who die prematurely increases. The greater the number of children who die prematurely, the worse the nutritional and health conditions. However, due to the problem of omission of children who died prematurely, this is for reference only.
▍ Conclusion
Although the continuation of incense and the succession of generations is the universal ideal of people, and people have made various efforts to this end, in reality, the ideal situation of children and grandchildren that people yearn for is rare, on the contrary, the extinction of heirs is a more universal reality. After these 267 years, only 13.61% of the people left their descendants, although the total population was growing during this period, but the phenomenon of extinction is still widespread, and people's ideal of continuing incense is sniped by the reality of universal extinction.
Among the many factors that affect heirs, the influence of the number of children is the most direct, and under the same mortality rate, the more children are born, the greater the chance of heirs. The number of children born is ultimately affected by socio-economic factors, and the patriarchs who occupy more resources and prestige in the genealogical data are prone to offspring, and those who have meritorious names are also prone to the continuation of this branch. In the process of population reproduction, these people who occupy more resources gain an advantage in the competition for survival, and this advantage is gradually accumulated and magnified, so that their descendants gradually occupy the main part of the population. The vulnerable population, which accounts for the majority of the population, is gradually excluded and eliminated, and eventually extinct. The largest 10% of the branches account for 62.72% of the total population, while the least 10% of the branches have only 1.25% of the total population, and the chances of reproduction are extremely unequal between the different branches.
In contemporary Europe and the United States, the population of developed countries is unwilling to have more children, while developing countries and regions such as Latin America, Africa, and Southeast Asia maintain relatively high fertility rates, and then the proportion of population in backward areas has increased, while the proportion of population in developed countries has declined. This reverse phase-out of the population presupposes that fertility and death are largely within human control, especially when epidemics and famines can be controlled more effectively. However, in traditional China, people obviously could not choose their own birth and control death, but instead, the level of death determined and shaped the reproduction mode of the population. In this case, then, the reproduction of the population may follow the natural law of "survival of the fittest", and those families with better socio-economic status can provide more adequate nutrition and relatively clean living conditions, especially in the event of large-scale epidemics and famines, with strong coping ability, so that the mortality rate is lower than that of those who are backward in social and economic levels. This makes the dominant family gradually grow in the process of reproduction, while the living space of the inferior family is gradually squeezed and eventually eliminated. It should be noted that with the continuous expansion of the population size of the descendants of the dominant family, there is also a gradual differentiation of advantages and disadvantages among the internal members, only a few descendants can inherit the advantages, while the majority of people are gradually degraded, so a new round of survival competition for survival of the fittest also unfolds.
This article was originally published in Southern Population, No. 6, 2012, originally titled "The Ideal of Continuing Incense and the Reality of Universal Extinction: Population Data Based on Genealogy". The article only represents the author's own views, welcome to share, media reprint please contact the copyright owner.