14 dic. 2007
When the sequence of the human genome was fully mapped in 2003, researchers discovered that our bodies are littered with fragments of retroviruses. These dangerous viruses managed to embed themselves in the DNA of our ancestors millions of years ago. They are called endogenous retroviruses, because once they infect the DNA of a species they become part of that species. One by one, though, after molecular battles that raged for thousands of generations, they have been defeated by evolution. Like dinosaur bones, these viral fragments are fossils and they reside within each of us, carrying a record that goes back millions of years. Read the complete article by clicking here, and listen to its audio version here. Excellent material for those of you interested in science and evolution.