Seriously though, aren't environmentally altered gene's being passed on a key part of evolution? Or did I really misunderstand that whole part of biology.
Apparently.
Natural selection, the key mechanism of evolution, has nothing to do with genes being "altered" over the course of an organism's lifetime. Rather, it has to do with the fact that organisms that are well-adapted to their environment tend to survive for longer than those that aren't, and so have a much greater opportunity to pass their significant genetic material, including said adaptations, on to their offspring. Over time, a particularly useful adaptation can wind up becoming the dominant trait amongst a population, simply because the members that exhibited it reproduced most effectively. One of the most visible signs of this process at work for Darwin was the finch population on the Galapagos Islands, which consisted of multiple species whose beaks were all shaped differently for handling different types of food. Darwin's theory on evolution via natural selection was a replacement for the older belief, known as
Lamarckism, which stated that traits acquired during an organism's lifetime could be passed down to its offspring. I've usually heard the latter expressed by the example of a giraffe who stretches out its neck constantly, thereby granting its children longer necks as well. By that logic, the babies Schwarzenegger would come out of the womb completely stacked.
(Another driving force of evolution is genetic drift, which is the change in gene variant frequency over the course of time due to random sampling and simple chance, but that process has nothing to do with how effective certain gene variants prove to be.)
