Food for thought #7

While lecturing years ago at the University of Helsinki, I told the audience that I do not know of a single case where the mutation/selection mechanism has created new information. I challenged the audience to help me. Maybe somebody knew of a good case. After a moment of silence, one man in the audience raised his hand and said he knew of one. His example was sickle cell anemia, a blood disease. It is caused by a single mutation in hemoglobin. The change makes blood cells crescent-shaped and causes severe anemia in those with the mutation, but the disease protects a person from the malaria parasite, which cannot reproduce in cells having this mutation. This is only a net benefit, though, when the mutation is inherited from only one parent (heterozygosis). If the gene is inherited from both parents (homozygosis), persons die young. Sickle cell anemia is not an example of the creative power of the mutation/selection mechanism. Information is not increased by this genetic mistake. It’s an example of nature breaking an existing biological mechanism, a break that creates a niche advantage, a common pattern that Lehigh University biologist Michael Behe explored in a 2010 peer-reviewed essay in The Quarterly Review of Biology. There he notes that “the rate of appearance of an adaptive mutation that would arise from the diminishment or elimination of the activity of a protein is expected to be 100–1000 times the rate of appearance of an adaptive mutation that requires specific changes to a gene.”20
Think of an old metal door with a flimsy lock, a door that eventually rusts shut. It’s now a pretty terrible doorway, but it does have one advantage over its pre-rusted self. It is harder to break open. If you didn’t need the doorway but wanted the security of that door being hard to break through, you might consider the outcome a net gain. But you would still have no reason to begin marvelling about the creative powers of rust. This is akin to the sickle cell anemia mutation. Something broke and created a niche advantage. But no novel molecular machine was created, much less a novel organ or organism.

Michael Behe, “Experimental Evolution, Loss of Function Mutations, and “the First Rule of Adaptive Evolution,” The Quarterly Review of Biology 85, no. 4 (2010).
Quoted from HERETIC, ONE SCIENTIST’S JOURNEY FROM DARWIN TO DESIGN by Matti Leisola and Jonathan Witt.

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