As the world fights with the global COVID19 pandemic, a team of scientists has revealed how humans have evolved to fight against some deadly diseases and how the diseases as well have become less toxic over time. Scientists have studied tens of thousands of age-old skeletons to come up with their findings. The findings of the study reveal how humans will be able to cope with diseases in the future. The study has shown how germs and bacteria mutate to multiply and ensure their endurance across as many human hosts as possible. However, this behavior lessens the severity of the ailments caused by these germs over time. Experts have said that ultimately these deadly viruses reach a sort of truce with the human body. In the study, experts have observed leprosy, tuberculosis, and treponematoses, a group of diseases, which includes syphilis. They have said that these ailments can leave stains on bones, teeth, which show the existence of the disease. Ancient human skeletons that can be traced back as far as 200 generations have been analyzed in the study. Maciej Henneberg, an anthropologist from Finders University in Australia has said that each of these diseases shows a drop in frequency that has resulted from a co-adaptation, which is helpful for the disease and the human host.
Experts have found that before the advent of modern medicine, skeleton signs of tuberculosis have become less common in the last 5000 years. Skeleton signs of leprosy as well have reduced towards the end of the middle ages. In North America, skeletal signs of treponematoses as well have seen a drop in the last few years before contact with invading Europeans. Experts have observed the findings of three past studies, which have included nearly 69379 skeletons. They have found that the ages of these skeletons have varied from as far back as 7250 BC until the present day. Scientists have said that not all human skeletons have belonged to people with tuberculosis, leprosy, and treponematoses. They have noted that not all the skeletons of people who have had these diseases have shown physical signs on the bones. It shows that the new study has not been a strict epidemiological meta-analysis. The samples, which have been used in the study, have been sufficiently large to draw some useful conclusions.
Experts have noted that none of these ailments claims people’s life immediately. It helps the viruses to live longer and spread quietly. However, statistically, the prevalence of these three ailments tuberculosis, leprosy, and treponematoses has reduced over time, which shows that human beings have gained more immunity against these diseases, which has made viruses less damaging. The authors of the study have said that on the evolutionary front, it makes sense for viruses to do less harm to their hosts on which their survival depends. Therefore, the high rate of transmission of such viruses seems to be a short-term evolutionary trait that lessens over time. This trend has been seen in diseases such as tuberculosis, leprosy, and treponematoses said the experts.