Posted on 12 October 2011 by Jim Walrod
Some words of reality for those of you who fail to understand the importance of the concept of evolution. Scientists studying the middle ages plague known as the Black Death have proven that without it, evolution that is, you wouldn’t be here.
Scientists have cracked the genetic code of the Black Death, one of history’s worst plagues, and found that its modern day bacterial descendants haven’t changed much over 600 years.
The evolution of society and medicine and our own bodies has far outpaced the evolution of that scourge of the middle ages.
The 14th century bug Yersinia pestis is nearly identical to the modern day version of the same germ. There are only a few dozen changes among the more than 4 million building blocks of DNA, according to a study published online in the journal Nature. So what does that have to do with you and your ancestors?
The study shows that the Black Death was deadly for reasons beyond its DNA. In its day, the disease killed 1 of every 3 Europeans. It came at the worst possible time when the climate was suddenly getting colder, the world was in the midst of a long war and horrible famine, and people were moving into closer quarters where the disease could infect them and spread easily.
In devastating the population, it changed the human immune system, wiping out people who couldn’t deal with the disease and leaving the stronger to survive. So if your sucking air right now and are of European descent guess what you have to thank for that?
The Black Death has not disappeared from the world. People still get the disease, usually from fleas from rodents or other animals, but not that often. There are around 2,000 cases a year in the world, mostly in rural areas, with a handful of them popping up in remote parts of the United States
To get the original Black Death DNA, scientists played dentist to dozens of skeletons.
During the epidemic in the 14th century, about 2,500 London area victims of the disease were buried in a special cemetery near the Tower of London. It was excavated in the mid-1980s with 600 individual skeletons moved to the Museum of London, said study co-author Kirsten Bos, also of McMaster University. She then removed 40 of those teeth, drilled into the pulp inside the teeth and got “this dark black powdery type material” which likely was dried blood that included DNA from the bacteria.
When the same scientists first tried mapping the bacteria’s genetic makeup, it appeared to be a distinctly different germ than what is around currently. But part of that was a reflection of working with 660-year-old DNA and newer, more refined techniques revealed less difference between the early day and modern Y. pestis bacteria than between a mother and daughter, Krause said.
So the bug is still out there, but you…you lucky Caucasian…are most likely immune thanks to the more evolved immune system of your ancestors that has been passed down to you.
Can you spell EVOLUTION?