A story I read recently about a new species of hominid discovered in Siberia left me feeling struck with the power of science. Inside a cave in the Altai Mountains, a single bone was discovered – the tip of an animal’s little finger. From this, scientists extracted 30 milligrams of mitochondrial DNA. From that, they were able to determine that the creature is an evolutionary relative of modern humans and that, furthermore, it represents a fourth independent instance in which human ancestors radiated out from Africa:
The common ancestor is, however, too recent for the new species to be a remnant of the first human excursion from Africa, the one that led to Java man and Peking man, now known as Homo erectus. It is, in other words, a fourth example of anthropological tourism from Africa to the rest of the world, on what is now looking like a well-worn route. Yet it is the lone example. That shows how fragmentary and ill-understood human history is.
The finger bone was found in strata dated to between 48,000 and 30,000 years ago (the bone itself has not yet been dated). That means the creature was contemporary with both Neanderthals and modern humans in the area.
It seems to me that there has been no other area of human endeavour which could have revealed so much using so little. Certainly, it demonstrates how much information is contained in ancient genetic material, and how powerful its analysis can be for understanding the history of life on Earth.