Iceman had brown eyes, DNA reveals
Oetzi the iceman, whose body was frozen into the Italian Alps 5,300 years ago, had brown eyes, type O blood, and was lactose intolerant, a DNA analysis shows.
He was also genetically predisposed to coronary heart disease and shows signs of the earliest known infection with Lyme disease, an international team of researchers reported Tuesday in the journal Nature Communications.
The well-preserved, mummified body was found in 1991 on the Tisenjoch Pass in the Italian part of the Oeztal Alps, which is why the iceman was nicknamed Oetzi.
Since then, researchers have conducted many studies on the body and found out a lot about Oetzi and how he died, including some genetic information from a special type of DNA called mitochondrial DNA that is passed down only through the maternal line.
However, the new study represents the first time that Oetzi's nuclear DNA, which comes from both parents, has been successfully analyzed. The DNA was extracted from a large pelvic bone called the ilium.
In addition to the information about Oetzi's eye colour and blood type, the DNA showed that he shared a common ancestor with people who now live on the islands of Corsica and Sardinia. The researchers said his genetic predisposition to coronary heart disease may explain some of the hardening of the blood vessels found during previous studies of his body.
The DNA sample also contained about 60 per cent of the genome of the bacterium that causes Lyme disease. That suggested that Oetzi was infected with the tick-borne disease, even though it was only first identified in North America in the mid-1970s.
The study was led by Andreas Keller of Saarland University in Germany, but included contributions from researchers around the world, including Brian O'Connor at the Ontario Institute for Cancer Research in Toronto.
Earlier analyses of Oetzi's body revealed he died violently from an arrow lodged in his left shoulder and had the blood of four different people on his clothes. He was wearing three layers of clothing made from goat, deerskin and bark.
Previous DNA samples taken from his intestines showed mutations typically found in men with reduced sperm function that can render them infertile.