Re: the emergence of the elderly accelerates human evolution and makes modern people stand out.
although life expectancy prolongs as time goes by, it is expected that the final result will surprise us. In all the samples, we have found a weaker trend: human life will be prolonged with the passing of time, but in the late Paleolithic modern people, compared with earlier ancient humans, the OY value changed very large, up by 5 times. That is to say, among Neanderthals, there are only 10 young individuals aged between 15~30 years old, who appear only 4 older than 30 years old individuals. In contrast, every 10 young stone age individuals in the same situation correspond to 20 elderly individuals who may become grandparents. We sometimes worry that this result will be caused by most of the old people buried in the ruins of the late Paleolithic era. To eliminate this doubt, we have analyzed some samples. Of the samples we selected, only fossils were not buried in the late Paleolithic period. But we got similar results. The conclusion is clear: in the history of evolution, the life expectancy of adults increased very late.
how to prolong life?
now, Professor Li Xiangxi and I have proved that at some point in the process of modern human evolution, the number of individuals who have the opportunity to become grandparents is growing rapidly, but at the same time we are facing another question: what is the cause of this change? There are two possibilities. First, from the biological point of view, the modern man and the ancient human are hereditary, and then there are many different structures in the human body, and longevity is one of them; the second may be that longevity is not accompanied by the emergence of modern human beings, but a "side effect" of human behavior changes. Anatomically, modern people have not suddenly "erupted" and evolved the ability to create art and make advanced weapons (Art and advanced weapons are the representative culture of the late Paleolithic). They appeared more than 100 thousand years earlier than the late Paleolithic Europeans. During most of this period, modern and the Neanderthal technologies used in the same period were simple technologies in the middle of the Paleolithic age.
although our research shows that the significant increase in the number of grandparents has indeed occurred after the emergence of modern people, it is not enough to explain whether this phenomenon is due to biological reasons or by cultural differences, because the modern people we study are all very important in anatomy and behavior. "Modern". Can we not modernize our behavior yet? Anatomically, some of the early modern people began to trace the source of the evolution of longevity.
to answer this question, I and Professor Li Xiangxi analyzed the human fossils of some of the sites in the Middle Paleolithic age of Western Asia, 40 thousand ~11 million years ago. Fossil samples include Neanderthals and modern people, and are accompanied by the same ancient simple artifacts unearthed. This allows us to compare the OY values of two groups that live in the same area and have the same culture, but are biologically different categories (many scholars believe that Neanderthals and modern people belong to different species that are isolated from each other). We found that the Western Asian Neanderthals and the modern people have the same statistical OY values, which means that in the Europeans of the late Paleolithic age, the longevity of adults was not caused by biological changes. Moreover, the OY values of the two groups in Western Asia are roughly equal to the average OY values of the European Neanderthals and early modern people.
compared with Neanderthals in Europe, the Siyani Andersons (and modern people) are more likely to become grandparents. This situation is not surprising. Compared with the ice age, the harsh natural conditions of Europe, the climate of West Asia is more moderate and more conducive to human survival. However, if mild climate conditions were the cause of the lengthening of adult life in the Middle Paleolithic age of Western Asia, the longevity of the late Paleolithic Europeans was even more unbelievable, because in the late Paleolithic age, Europeans lived in a worse environment, but their OY value was more than two times more than the old stone. A modern man in the middle of the age of the apparatus.
older people change the evolution of
we can't determine what changes in the culture of the Europeans in the late Paleolithic have enabled so many of them to live to a larger age. But there is no doubt about this: the prolongation of the life span of adults has a profound effect. Kristen Hawkes (Kristen Hawkes) of the University of Utah, Hillard Kaplan (Hillard Kaplan) of the University of New Mexico, and some other researchers have studied several existing hunting - born people who have found that grandparents often provide economic and social support to their offspring in their daily life. Their offspring are increasing both in number and in survival. Grandparents also solidify complex social relationships, like my grandmother, who often tells the stories of their grandparents, linking me with the other relatives of my generation. Such information is the basis for building a human social system.
older people also pass on cultural knowledge to future generations, from the environmental aspects (which plants are toxic or where water can be found in the drought period) to the technical level (how to weave baskets or make a stone knife). Pontus Strimling, of the Stockholm University in Sweden, found that repetition is a key factor in the inheritance of some cultural traditions or rules. Families of multiple generations have more family members to repeat important information about family. Therefore, longevity contributes to the accumulation and transmission of information from generation to generation, which can promote the formation of complex kinship and other social relations networks, and help each other when circumstances become difficult. The prolongation of the life span of
can also be understood as increasing the number of groups by increasing the age. Moreover, this newly added age group has reproductive capacity, which has never been seen before. A large population is the main driving force for new behaviors. In 2009, Adam Powell (Adam Powell) of the University College London, UK, and colleagues published an article in science that the population density played an important role in the maintenance of cultural complexity. They and other researchers have suggested that a large population has promoted the development of a wide range of trade networks, complex system cooperation, individual goods processing and group identification, such as jewelry, body painting, and so on. From this point of view, the main characteristics of the late Paleolithic age - widely used symbols, the use of special materials manufacturing tools, and so on, are likely to be the result of rapid population growth.
the increasing population may have influenced our ancestors in another way: accelerating the pace of evolution. As the University of Wisconsin at Madison's John Hawkes (John Hawks) emphasizes, the more the population means, the more mutations that occur, and the more opportunities for rapid mutation in the population. Compared to the Paleolithic people in the late Paleolithic age, this trend was even more shocking to modern modern people: with the growth of the population, our ancestors began to grow crops 10 thousand years ago. In 2009, Gregory Kirkland (Gregory Cochran) and Henry Hapentine (Henry Harpending) of the University of Utah, in their work "the The 10000 Year Explosion", enumerated various mutant genes that have produced and spread rapidly over the past ten thousand years - from determining the color of the skin to the influence. There are all genes that are resistant to milk. These mutations are attributable to the increase in population.
the life span of an adult will interact with the cultural tradition rising in the late Paleolithic age, and the relationship between them is a positive feedback process. At first, longevity was only a "by-product" of some cultural changes, but later it became the precondition of modern behavior. In turn, the unique and complex modern behavior has made the elderly more important, improving their survival rate and causing population expansion. The expansion of population has deeply influenced the culture and heredity of ancestors. This is just as the saying goes, ginger is still hot.