Human Evolution In Action: In the Last 200 Years

by Pappy November 23rd, 2009, Posted in: Evolution , Religion , Science

Fore tribe membersImagine this:

You are a member of the Fore tribe in Papua New Guinea, living in relatively small tribal and family groups. Your beloved Uncle has died and you are preparing to take part in a traditional funeral ritual to honor him. As part of the ritual, Uncle’s brains are ceremonially eaten by you and your family; it is a mark of respect.

The event is repeated through the years as other family members die. Some time later, many of your neighbors and even some of your own family members begin dying off rapidly. Even though your people wont eat anyone known to be diseased, the death rate spirals upwards. But not you, nor any of your children. You still continue the traditional practice of eating human brains, and see no negative effects at all. You have no idea that a brain wasting disease, called kuru, is sweeping through your culture. You have no idea that your genes protect you against kuru and have been passed on to your descendants. You may be clueless, but you are an evolved human.

Similar to mad cow disease, kuru is spread through the consumption of infected brains. It spread its way through the Fore tribe, killing at least 2500 members in the twentieth century until its cause was discovered in the 1960s, and the brain-eating practice was finally abandoned. At it’s height, between 1957 and 1968, over 1100 members of the South Fore, mostly women, died of kuru. At one point, there were almost no women remaining in some Fore territories.

Kuru is taken from the Fore word “kuria/guria”, ‘to shake’. It is also known as the laughing sickness due to the pathologic bursts of laughter people would display when afflicted with the disease.

This amazing tale is true, and this week scientists have revealed the even more amazing details behind the discovery. Let’s break down the specifics, released by Simon Mead of the British prion research center at University College London:

  • Mead and colleagues discovered a mutated gene after comparing the stored DNA of 152 Fore kuru victims with over 3000 living Fore members, including nearly 600 who participated in the brain eating practice.
  • In 51 survivors they discovered a variant of PRNP, the gene that makes prions, which are the proteins that spread the disease.
  • The change in the gene comes at a position called codon 127. Throughout the animal kingdom, the codon contains the same amino acid, called glycine or “G”, from each parent, giving the form G127G. To their astonishment, Mead and his colleagues found a variant of the codon never seen in nature before, in which one of the glycines has been swapped for a valine amino acid, giving the new variant the name G127V.
  • The mutation first arose about 200 years ago by accident in a single individual, who then passed it down to his or her descendants, and so on to today’s generation, who still carry the gene.
  • It was a very sudden genetic change under intense selection pressure from the disease.

It comes as no surprise that, just as Darwin showed evolution to occur in the Galapagos, the transition arose and took root in an isolated human population with almost no genetic transfer with the outside world. As if the DNA weren’t proof enough, the mechanisms and conditions under which evolution operates are further demonstrated in this instance as well. This is indeed a very specific and demonstrable case of human evolution, observed almost literally as it happened.

As Mead stated in his release, “I hope it will become a textbook example of how evolution happens. It’s a striking and timely example, given the 150th anniversary of the publication of Darwin’s Origin of Species,” he says.

Finally, in keeping with my recent campaign, ol’ Pappy has to poke a dead dog in the eye for no other reason than to watch the twitchy, nervous response that corpses sometimes exhibit when properly agitated. I propose the following conundrum to our religious faithful who will insist this proves nothing:

If this is NOT proof of evolution in humans, then the Fore, and only the Fore people, were granted this genetic miracle by God. As the gene protects the practitioners of cannibalism, doesn’t God therefore condone or even encourage the practice? Does this finally prove that the practice of communion has it’s origins in cannibalism like some of us have been suggesting all along? Does God not love the rest of us enough to bless us as well, given the G127V variant may also protect humans from other prion diseases? And if God created the miracle, then which God? The entire kuru epidemic, the resulting genetic mutation, and the abandonment of cannibalism all happened prior to any exposure to, or influence from, the so-called “true” religions of christianity, judaism, or islam.

Did I say I was only going to poke it once?

Pappy out.

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