Gene mutations that once helped humans evolve and survive could increase the risk of cancer and other diseases today, researchers in Israel said.

The mutations were found in the genome of the mitochondria, the part of cells responsible for energy production that is passed from mother to child, scientists at Ben-Gurion University of the Negev said.

"Although mitochondria's role in the emergence of new species has been investigated recently, the idea that they are responsible for our susceptibility to illness startles many," Dr. Dan Mishmar, a molecular biologist at the university, said in a release Friday.

Mishmar's team found the mitochondrial genome of humans who migrated out of Africa to Europe 100,000 years ago carried seven mutations found in almost all of today's Europeans.

"If we better understand how evolution moved, we can understand the genetic basis of many complex disorders," Mishmar said. "This may lead to new methods of disease prevention or cures."