500 years later, the murderer of the “holocaust” was caught

  An unsolved medical case 500 years ago was solved by several anthropologists 500 years later.
  The murderer had nowhere to hide under the microscope, and even though they were cut into gene fragments by time, they were recognized by brilliant scientists.
  According to historical records, in the middle of the 16th century, shortly after the Spanish conquered Central America, a devastating disease called the “Great Plague” by the locals swept Mexico and Guatemala.
  Almost all people infected with the plague died. The symptoms of the plague patient were recorded in detail: “Fever, extremely contagious, black tip of the tongue, extremely dry. The pulse beats extremely fast, then weakens, accompanied by heartache, chest pain, abdominal pain, tremor, extreme anxiety and dysentery. ”
  Since the first outbreak of the Great Plague in 1545, the population of Mexico has dropped from 20 million to 2 million in less than a century. A European missionary described the apocalyptic scene there in his diary: “From morning to sunset, the priests have no choice but to throw the dead body into the ditch.”
  However, the murderer of this “massage” Who is it? History circles have been arguing. Some researchers believe that the Spanish invaders are to blame, after all, smallpox, measles, and typhus are inextricably linked to them. Some people think that this is an unknown virus in Mexico, not to blame the Europeans.
  The once prosperous mountain city became a dead city. The survivors moved down the mountain, buried the dead in the dirt, and forgotten them on the top of the mountain. The secret remained silent for 500 years.
  Without conclusive evidence, modern scientists cannot determine whether it is measles, smallpox or typhus. Nowadays, there is a group of people obsessed with doing “mystery solving”.
  Christen Boss, an anthropologist who specializes in the relationship between ancient DNA and infectious diseases, is a “slash young man” in archaeology. From the Max Planck Institute of Human History Science in Germany, she is keen to find out “murderers” who are almost forgotten by the world.
  Previously, she had used this technology to confirm to the victims of the Black Death that they were infected with the plague virus. She has also tested the culprits of leprosy, cholera, tuberculosis and paratyphoid fever.
  This time, the secret of the great plague is buried in a large cemetery in the mountains of Mexico. Since 2004, the Boss team has been studying more than 800 corpses buried inside.
  By extracting DNA from 29 skeleton teeth in the cemetery for analysis, Boss and her team found that 11 of the skeletons contained DNA fragments of Salmonella intestinal tract.
  When bacterial DNA appears in the dental pulp, it means that it has entered the blood circulation, which is likely to cause a rare sepsis reaction before the invention of antibiotics. Salmonella intestinal bacteria may be the culprit that caused the outbreak of the plague.
  In addition to DNA, human bones and geographical environment may hide clues. As long as the method is right, it is not impossible to let these dead “speak”.
  In the tomb of the Shang nobles in Heying, Anhui, the dead bones of the burial were fragmented, and they were suffering from osteoporosis. The excessive lead content in their bones may be caused by heavy use of bronze vessels for drinking.
  In 1996, archaeologists discovered a frozen Inca mummy Juanita on the Andes. Ten years later, scientists took samples from the mummy’s lips and used protein analysis techniques to speculate that the girl was infected with a deadly virus similar to tuberculosis bacillus before her death.
  The ancient DNA test is more difficult. Over time, DNA molecules will automatically degrade and become fragmented fragments. Thanks to the deceased’s hard teeth, they were eventually captured by the researchers.
  In order to confirm that the DNA fragments found in the teeth belong to Salmonella, Bosch’s team must reconstruct the entire genome. “It’s like a broken mirror, you have to try to put it back together.” Boss explained. They used “bait” specially tailored for Salmonella to capture DNA fragments that matched the genome, and then used modern Salmonella genomes as scaffolds to put these fragments together like a jigsaw, and found that the target was consistent.
  In addition to catching the culprit of the great plague, this research has unexpected gains-Europeans are responsible for this disaster. Five other corpses found in the same cemetery were buried before the Spanish invasion. Researchers did not find that Salmonella was rampant in the pulp of the dead. This may mean that the virus followed the invaders that year and crossed the oceans, and the indigenous people were unable to resist, leading to the most serious epidemic in human history.
  ”DNA determination has opened a door to ancient times for us.” Boss said excitedly. The human body is perishable, but microorganisms are not perishable.
  The wild and brutal Salmonella may also be tamed by humans. Recently, scientists have discovered through experiments in mice that by modifying the genetic circuit of Salmonella, it can induce an immune response that can effectively kill cancer cells. An idea of ​​a good medicine for cancer. It’s like a villain who is full of crimes, who can accept reform from good to good.