What kind of evolution can you expect in 450 iterations?

Actually quite a lot. The pace of evolutionary change is a function of the amount of variation present in a population and the intensity of selection (i.e. the death rate). There was one study done of the variation of bone dimensions present in modern populations of chimpanzees that suggests that the transition from chimpanzee-style locomotion to full bipedality (at least the variant of bipedality observed in Ardipithecus (~5 million years ago) could have happened on the scale of a few thousand years.

This is not to say that it did happen that fast, just that it could have given a strong enough intensity of selection. There is a weird tendency in paleoanthropology for researchers to propose something that might have happened and it becomes accepted by the general public as something that did happen.

Actually, this math is almost exactly how the young earth creationist cult came to their number for the age of the earth. The counted out all the begats in the Bible from Adam to Jesus and multiplied by an average amount of time between births.

Exactly. The fact that our kids can look different from us at all is fucking wild