Was just sorta thinking...how did blood 'evolve'? Did the veins and arteries accidentally mutate first, then later blood mutated from other stuff and start flowing? What about the heart? Did it mutate itself to become connected to the blood-highways? When or how would the brain have evolved to know to control a heart, or lungs? When the first small-cellular animals either decided or mutated into larger animals, which parts of the larger animals were among the first anomalies to happen/chance themselves into existence? If we can identify one mutation, say, an ancient animal mutating parts of itself, or having a mutation that was indeed a heart, what kept the heart alive - what tissue worked to ensure the DNA-footprint for a heart passed on to others of its kind? I put this thread in this subforum because macro evolution is most-certainly a religion akin to man-made global warming and what-not.