DNA

DNA, the molecule carrying the genetic instructions of life, was arguably one of the most important discoveries of the last century. DNA is used in the development of all forms of known life, is composed of 4 nucleotides, and has the form of a double helix. This is a timeline of the discovery and development of DNA.

Scientists made a remarkable discovery at Trou Al’Wesse in Belgium earlier this year. Inside a cave that overlooks the Hoyoux river they found clear evidence it had been occupied by Neanderthals tens of thousands of years ago. Yet the cave contained no skull fragments, no teeth – nor any other skeletal remains of this extinct species of human being.

The team, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, were sure of their ground, however. Their genetic analysis of soil samples, scraped from the cave floor, had pinpointed the presence of Neanderthals through that most definitive of biological markers: their DNA.

In other words, without digging up a bone or a molar, the team, led by geneticist Matthias Meyer, had found – merely by studying a few microscopic strands of DNA – that tens of thousands of years ago Neanderthals had sheltered at Trou Al’Wesse. It was the scientific equivalent of “extracting gold dust from the air”, as one researcher put it.

Meyer’s project is an example of the astonishing advances that have been made in studying ancient genomes. Apart from detecting the presence of Neanderthals and other ancient people at sites devoid of any other remains, researchers are also using these techniques to uncover ancient population movements, pinpoint previously unknown human species, track the evolution of human illnesses and uncover the sources of human creativity. A new window has been opened on to our past.