Evanzant's List: Evolution

• three complement pathways
• All three pathways converge at an enzyme activity called C3 convertase
• There has been a great deal of debate about the evolutionary history of the complement pathways.
• It is thought that much of the vertebrate complement system arose from duplication of genes encoding C3/C4/C5, Bf/C2, C1s/C1r/MASP-1/MASP-2, and C6/C7/C8/C9 molecules⁹
• It appears then that the vertebrate pathways could not have evolved in a Darwinian fashion from earlier lectin pathways, because they are dependent upon the activity of C3 convertase
• It appears then that the vertebrate pathways could not have evolved in a Darwinian fashion from earlier lectin pathways, because they are dependent upon the activity of C3 convertase
• C2b is also known as C3 convertase,

  • Differs from SC video series which indicates that C4b2a is C3
    Convertase
    
• So while vertebrate classical pathways are irreducibly complex in that the entire pathway is dependent upon at least one enzyme, it is clear that evolutionarily older organisms possess a functional pathway even in the absence of that enzyme.
• "Darwinian evolution can easily produce irreducible complexity: all that's required is that parts that were once just favorable become, because of later changes, essential."¹⁹

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• There is a common tendency to overinterpret animals exhibiting such clever behaviors, imputing to them much more comprehension than they need, or have, and an equally common tendency, in reaction, to underestimate them.
• According to calculations by MacCready, at the dawn of human agriculture, the worldwide human population plus livestock and pets was ≈0.1% of the terrestrial vertebrate biomass. Today, he calculates, it is 98%!
• Because we don't have everyday terms for semiunderstood quasi-beliefs, we have no stable vocabulary for describing the cascade of Turing-powers that climbs to the summit of our particular human levels of comprehension.
• This lexical dearth helps to sustain the illusion that there is an unbridgeable gulf between animal minds and human minds—despite the obvious fact that similar quandaries of interpretation afflict us when we turn to young children

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