Evolution May Have Made Humans More Cancer Prone
Scientist thinks bigger brain could explain difference from chimps
FRIDAY, June 12, 2009 (HealthDay News) -- Did humans lose some of their ability to ward off cancer in return for developing a more advanced brain?
That's a possibility, says a Georgia Institute of Technology researcher who found that the genes of chimpanzees are better than those of humans at apoptosis, or programmed cell death -- one of the main ways the body kills cancer cells.
John McDonald, chairman of Georgia Tech's School of Biology and chief research scientist at the Ovarian Cancer Institute, made the finding when comparing gene expression in the brain, testes, liver, kidneys and heart of chimps and humans. Chimps, which are considered human's evolutionary kin, have lower cancer rates than humans -- a fact that McDonald said has always intrigued him.
"The results from our analysis suggest that humans aren't as efficient as chimpanzees in carrying out programmed cell death," he said in a Georgia Tech news release. "We believe this difference may have evolved as a way to increase brain size and associated cognitive ability in humans, but the cost could be an increased propensity for cancer."
The findings appear online in the journal Medical Hypothesis.
The U.S. National Cancer Institute has more about understanding cancer.