Ancient DNA extracted from the 5,000-year-old remains of two individuals has revealed a mitochondrial haplogroup previously unknown in the New World. The individuals, two young adult males discovered at the China Lake site in central British Columbia, Canada, were found to belong to haplogroup M. This discovery suggests that there was a greater genetic diversity among ancient Americans than researchers had assumed, said Ripan Malhi, a molecular anthropologist at the University of Illinois, Urbana-Champaign, who conducted the DNA tests.

Researchers had identified five haplogroups - a term used to describe genetic lineages - in the mitochondrial DNA of living Native Americans. Those haplogroups are known as A, B, C, D, and X, and it was assumed that these remains would fall into one of these groups. Malhi said he was "very surprised" to find that wasn't the case, so surprised, in fact, that he at first assumed that the samples he tested were contaminated. But additional testing confirmed the results.

The remains were accidentally discovered in 1982 during a road construction project. "We think they were buried together or within a short period of time of one another," said Jerry Cybulski, the curator of physical anthropology at the Canadian Museum of Civilization in Gatineau, Quebec. A bone sample from the remains was radiocarbon dated to roughly 5,000 years ago. Cybulski analyzed the skeletons in 2000. These individuals were shorter and their bones were thinner than the roughly 100 other ancient human skeletons that have been found in this region.

Cybulski met with the Canoe Creek Band of Salish Indians in 2002 to get permission for testing. There have been cases where Native Americans have opposed DNA testing of ancient remains that they believe to be their ancestors. The legal wrangling surrounding Kennewick Man is the best known example of this. But this posed no problem for Cybulski, who wanted to test the remains to see if they were related. "We've had an ongoing relationship with the Canoe Creek Band," he said. Consequently, the Canoe Creek allowed Cybulski, Malhi, and their colleagues to conduct the DNA tests. Once these tests were concluded, the individuals were reburied.

Like the five known Native American haplogroups, M has been traced back to Asia, so it is consistent with the theory that the first Americans were Asian people who crossed Beringia en route to the Americas. "This type of lineage may have come in with the first Americans, or it may have come in later in time," Malhi said. "I wouldn't be surprised if we discover more haplogroups in the future." He speculated that the M haplogroup could have "died out" over time. "That could be the result of random extinction processes."

The remains of a female of similar age were also found near China Lake, and DNA testing revealed she belonged to haplogroup A.