The ancestors of the camel family originally originated in North America about 50 million years ago. During the Quaternary glacial period, due to the decrease of sea level, one of them crossed the Bering Strait, went from North America to Asia, and evolved into our common Bactrian camel and African single humped camel. There are only four kinds of humpless camel in South America: guanaco, vicuna, llama and alpaca. Among these four kinds of camels, the alpaca and the llama are wild species, while the llama and alpaca are domesticated species (please keep these four names in mind, because they will appear again and again, which is very easy to remember). After the last time out of Africa, human beings gradually spread to Eurasia. After the last ice age (about 20000 years ago), human beings further crossed the Bering Strait from Asia to America. < p > < p > we all know that Turkey is a must-have food for Thanksgiving, but the main function of an innocent, harmless animal like a guinea pig in South America is to be a food! In the past, people living in South America almost had guinea pigs at home, and they would roast a guinea pig to entertain guests on New Year’s holidays (I won’t eat it anyway). < / P > < p > but over time, you have to change your taste. Besides, as far as the adaptability to nature is concerned, human beings are very dependent on it. In addition to food provided by animals, even clothes have to be provided. For example, alpaca hair is a natural raw material for all kinds of textiles (from the appearance of the alpaca after it has been plucked, we can see how much wool there is, and there are dozens of natural colors). In addition, because alpacas are located in South America, there are very few natural enemies. So they are very gentle and lovely. For example, never bite, because there is no upper front teeth! < / P > < p > in this regard, human domestication of animals is like a boy chasing a girl, neither of whom is too sensitive to succeed. For example, in the fierce competition for survival in the African prairie all year round, even the zebra, which we think is very “docile”, has developed the character of being open to the slightest wind and grass (no wonder, until now, there is no domesticated animal on the African prairie…). In addition to relying on animals for food and clothing, humans also calculate costs. Let the horse run, but also let the horse eat less. Domestication of animals is also the first consideration to find a grass only, not meat. Alpaca is particularly “striving for success”, which perfectly conforms to this point! In the end, the alpaca with a bit of innate fatalism was born (Hegel: being is reasonable, everything in reality has its logic of existence!). < / P > < p > seems so reasonable, but there is still a question: which wild species is this Alpaca domesticated from? In fact, the international scientists have not been very clear about it. Some said it was made from guanaco, some said it was vicuna, and some said it was made by guanaco and llama. < p > < p > until recently, Zhan Xiangjiang Laboratory of Institute of zoology, Chinese Academy of Sciences, together with scientists at home and abroad, published research papers in the international journal Genome Biology, which systematically solved the mystery of Alpaca’s life experience at the genomic level: your father (ancestor) is vicuna. however!! There was also a “Uncle Wang” next door in history, which was llama. < / P > < p > first of all, scientists collected samples of these four camel species in the Andes region of South America, namely two domesticated species (alpaca and llama), and two wild species (guanaco and vicuna). < / P > < p > after getting the DNA sequence, the first thing to do is to use the phylogenetic tree to construct and describe the evolutionary relationship between them. Let’s record it as a tree. However, the a-tree is a little strange: the two wild species, guanaco and vicuna, have been separated for a long time, which is understandable. After all, they are two wild species. It is not controversial that llama is the offspring of guanaco, and previous studies support this conclusion. < / P > < p > but, but! Alpacas, on the other hand, have a much older evolutionary relationship than vicuna, which seems to have been domesticated from alpacas. It doesn’t make sense logically: how can wild species be the offspring of domesticated species? In fact, about 36% of the DNA components of Alpaca are infiltrated from llama, which may cause alpaca and llama to get closer to a tree, which makes people think that vicuna is an illusion that alpaca was domesticated from alpaca. < p > < p > therefore, through the operation of “local ancestry inference”, scientists further screened out these DNA fragments, and found that they were indeed normal! < / P > < p > not only that, scientists found that llama gave Alpaca about 36% of DNA, and alpaca gave back about 5% of llama’s DNA. These large-scale “reciprocity of propriety” caused the inconsistency of previous researchers. < / P > < p > so, after knowing the question of “who am I”, scientists have a new question: when did this “reciprocity” happen? How did it happen? (did anyone force them?) < / P > < p > to find out the answer to this question, scientists counted the length of these DNA fragments and calculated the most likely time of “reciprocity” by constructing a statistical model called “recombination decay”. < / P > < p > the results show that the two times are relatively close, both about 500 years ago! It was the 1630s. (Alpaca OS: 500 years, you still found it!) < p > < p > opening the history textbook, we found that the 1630s, for South America, was a very critical period in the history of civilization development, and even changed the development track of South American civilization! Before the 16th century, it was the Inca empire that ruled South America. The Inca Empire created the once brilliant Inca civilization, which was called “three American civilizations” together with Maya civilization and astech civilization. However, with the discovery of the American continent by Columbus in 1492, the Europeans started the wave of colonial expansion. It was in the 1630s that the Spanish arrived in South America. When the two armies meet, there will be a war. There is no suspense about this war. We can imagine that the Spaniards who face the bonus of guns and cavalry don’t even have cavalry The Indian, almost no ability to resist. The Spaniards easily conquered South America and opened the colonial era. From this we can see how important animal domestication is to the development of human civilization! After the Spanish occupation, they not only slaughtered Indians, but also animals. By inferring the historical size of population dynamics, researchers also confirmed that the number of Alpaca accelerated at that time. < / P > < p > at the same time, the Spaniards are stupid and confused about alpaca and llama. These two kinds of camel are mixed breeding together. This chaotic management has resulted in a large-scale gene penetration (reciprocity) phenomenon that we have seen above. < / P > < p > although the arrival of the Spanish conqueror had a great impact on the local traditional Alpaca management, it is gratifying that since then, the alpaca species has also gone from South America to the world!