Evolution is simple. What's to disagree with?

A common analogy when explaining the relationship between microevolution and macroevolution is walking. Each step in a walk takes one only a tiny distance, but one can walk all the way from New York to San Francisco one tiny step at a time. In the same way that the steps in a walk can accumulate into long distances, the small steps of microevolution gradually accumulate into large macroevolutionary changes.The observations and conclusions you're responding to note that because all reproduction is imperfect that genetic change over time is inevitable. There is nothing that can prevent it, and natural selection locks in changes consistent with success in the environment. In other words, there is nothing that can stop the tiny steps of microevolution from taking place, and given that environmental change is just as inevitable the genetic changes will accumulate and eventually take the population long "distances" (genetically) from their original state.A common response to the walking analogy is that macroevolution is actually like walking from New York to Paris - simply not possible. What's missing from this form of the analogy is the genetic equivalent of the Atlantic Ocean.--Percy