Monday, November 10, 2008
Ancient DNA, Modern Diseases
A recent National Geographic article reports that German scientists have discovered the earliest known cases of malaria – about 3,500 years old, to be exact. The researchers, who studied bone tissue samples in more than 90 Egyptian mummies, believe their findings could enlarge the current understanding of how modern diseases mutate in response to drugs. They also hope that "strategies to prevent the introduction of new infectious diseases or the re-emergence of ancient ones" might result.
Frank Rühli, head of the Swiss Mummy Project at the University of Zurich, asserts the importance of these findings:
"If you go back in the past and see th[e] genetic fingerprint [of a disease], say a hundred years ago or a thousand years ago or ten thousand years ago, it helps you to assess how it might actually react in the future."
There is no effective vaccine for malaria, and millions of people die from the disease every year. For this reason, the article claims that the findings take on additional importance: “Ancient samples of a microorganism's genetic code can show what its DNA looked like before any of its known mutations developed. An antibiotic designed to target a disease-causing bacteria in its earliest stages could then potentially cure its modern variations.”
Researchers are also studying ancient strains of tuberculosis, a potentially fatal bacterial infection. In 2007, they unearthed a 500,000 year old fragment of a Homo erectus skull with lesions that suggest TB, and recently, researchers located two of the oldest cases of TB in early humans to date. The article can be found here: http://news.nationalgeographic.com/news/2007/12/071207-tb-evolution.html.
With many diseases gaining resistance to antibiotics, this research has many potential benefits.