Eating Brains
Our ancestors may have
eaten each other's brains, infact cannibalism and Prion Disease may have been
rampant in ancient humans as Elizabeth Pennisi wrote in her commentary (Science,
Apr 11, 227-228, 2003). A team of researchers led by John Collinge of
University College in London suggests that cannibalism may have caused
epidemics of kuru and Creutzfeld Jacob disease, which can be spread by eating
contaminated flesh. Natural selection would then have favored people with
mutations, allowing them to survive and reproduce. Those two diseases and the
human form of mad cow disease are believed to be caused by prions, an abnormal
protein that can cause proteins to clump in the brain. The British research team
reported that protective genes, selected through polymorphisms, are mutant
versions of the prion protein gene and show signs of having spread among the
population by the means of natural selection. The prion disease has provided
the selection pressure to widespread the protective gene polymorphisms among
humans.
John
Whitfield in Nature News (see Our
ancestors had brains – for dinner, April, 11, 2003,
still online on May) resumes an article
(Mead, S. et al. Balancing selection at the
prion protein gene consistent with prehistoric kurulike epidemcis. Science,
published online, doi:10.1126/science.1083320, 2003)
on a terrible and fascinating subject which is dedicated the book The Trembling Mountain: a personal account of Kuru, Cannibals and Mad
Cow Disease, written by Robert
Klitzman, M.D. (amazon).
BM&L-May2003