Every family has its skeletons in the cave, though, so Manfred Hucht-hausen, 58, a teacher, and 48-year-old surveyor Uwe Lange remained in celebratory mood.

Thanks to DNA testing of remarkably well-preserved Bronze Age bones, they can claim to have the longest proven family tree in the world. “I can trace my family back by name to 1550,” Mr Lange said. “Now I can go back 120 generations.”

The good news for two villagers in the Söse valley of Germany yesterday was that they have discovered their great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great grandparents — give or take a generation or two.

The bad news is that their long-lost ancestors may have grilled and eaten other members of their clan.

Every family has its skeletons in the cave, though, so Manfred Hucht-hausen, 58, a teacher, and 48-year-old surveyor Uwe Lange remained in celebratory mood. Thanks to DNA testing of remarkably well-preserved Bronze Age bones, they can claim to have the longest proven family tree in the world. “I can trace my family back by name to 1550,” Mr Lange said. “Now I can go back 120 generations.”

Mr Lange comes from the village of Nienstedt, in Lower Saxony, in the foothills of the Harz mountain range. “We used to play in these caves as kids. If I’d known that there were 3,000-year-old relatives buried there I wouldn’t have set foot in the place.”

The cave, the Lichtensteinhöhle, is made up of five interlocked natural chambers. It stayed hidden from view until 1980 and was not researched properly until 1993. The archaeologist Stefan Flindt found 40 skeletons along with what appeared to be cult objects. It was a mystery: Bronze Age man was usually buried in a field. Different theories were considered. Perhaps some of the bodies had been offered as human sacrifice, or one generation had been eaten by another.

Scientists at the University of Göttingen found that the bones had been protected by a thick layer of calcium: water dripping through the roof of the limestone cave had helped to create a sheath around the skeletons.

The analysis showed that all the bones were from the same family and the scientists speculated that it was a living area and a ceremonial burial place.

About 300 locals agreed to giving saliva swabs. Two of the cave family had a very rare genetic pattern – and a match was found.

The skulls have been reconstructed using three-dimensional computer techniques and placed in a museum. “It was really strange to look the man deep in the eyes,” Mr Lange said.

The bones of history

— The oldest human genetic material is thought to have been discovered at the Sterkfontein Caves near Johannesburg in 2001

— Fossilised faeces found in Oregon this year contained DNA dating back 14,000 years, placing people genetically similar to Native Americans in the area 1,000 years earlier than previously thought

— Australian scientists announced in 2001 that they had extracted DNA from the country’s oldest human skeleton, 60,000-year-old Mungo Man, who is distinct from the line that previously suggested all modern humans traced back to Africa

source: UK Times

People with blue eyes have a single, common ancestor, according to new research.

A team of scientists has tracked down a genetic mutation that leads to blue eyes. The mutation occurred between 6,000 and 10,000 years ago, so it seems that prior to this time, no one had blue eyes.

“Originally, we all had brown eyes,” said Hans Eiberg from the Department of Cellular and Molecular Medicine at the University of Copenhagen.

The mutation affected the OCA2 gene, which is involved in the production of melanin, the pigment that gives color to our hair, eyes and skin.

“A genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ’switch,’ which literally ‘turned off’ the ability to produce brown eyes,” Eiberg said.

The genetic switch is located in the gene adjacent to OCA2 and rather than completely turning off the gene, the switch limits its action, which reduces the production of melanin in the iris. In effect, the turned-down switch diluted brown eyes to blue. Further, if the OCA2 gene had been completely shut down, our hair, eyes and skin would be melanin-less, a condition known as albinism.

“It’s exactly what I sort of expected to see from what we know about selection around this area,” said John Hawks of the University of Wisconsin-Madison, referring to the study results regarding the OCA2 gene. Hawks was not involved in the current study.

Your Baby Blues
Eiberg and his team examined DNA from mitochondria, the cells’ energy-making structures, of blue-eyed individuals in countries including Jordan, Denmark, and Turkey. This genetic material comes from females, so it can trace maternal lineages.

They specifically looked at sequences of DNA on the OCA2 gene and the genetic mutation associated with turning down melanin production.

Over the course of several generations, segments of ancestral DNA get shuffled so that individuals have varying sequences. Some of these segments, however, that haven’t been reshuffled are called haplotypes. If a group of individuals shares long haplotypes, that means the sequence arose relatively recently in our human ancestors. The DNA sequence didn’t have enough time to get mixed up.

“What they were able to show is that the people who have blue eyes in Denmark, as far as Jordan, these people all have this same haplotype, they all have exactly the same gene changes that are all linked to this one mutation that makes eyes blue,” Hawks said in a telephone interview.

Melanin switch
The mutation is what regulates the OCA2 switch for melanin production. Depending on the amount of melanin in the iris, a person can end up with eye color ranging from brown to green. Brown-eyed individuals have considerable individual variation in the area of their DNA that controls melanin production. But they found that blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes.

“Out of 800 persons we have only found one person which didn’t fit — but his eye color was blue with a single brown spot,” Eiberg told LiveScience, referring to the finding that blue-eyed individuals all had the same sequence of DNA linked with melanin production.

“From this we can conclude that all blue-eyed individuals are linked to the same ancestor,” Eiberg said. “They have all inherited the same switch at exactly the same spot in their DNA.” Eiberg and his colleagues detailed their study in the Jan. 3 online edition of the journal Human Genetics.

That genetic switch somehow spread throughout Europe and now other parts of the world.

“The question really is, ‘Why did we go from having nobody on Earth with blue eyes 10,000 years ago to having 20 or 40 percent of Europeans having blue eyes now?” Hawks said. “This gene does something good for people. It makes them have more kids.”

from MSNBC