Thanks again, John. I didn’t mean that exactly. I was referring back to the example in this thread. There was a whale that have vestigial hind limbs. Those limbs were referred to as being leftovers, so to speak, from the predecessor. These “hind limbs” were said to be remnants from a four-legged land animal from which the whale evolved. So, my question was regarding why, when we see something like the remnant of a hind limb that is not used by a whale, it is assumed to be a remnant from the past rather than something developing for the future.
The reason for asking this question is because of the next point that I make… namely, that if you go back far enough in time, you will find very simple animals. From that point forward, all of the functions or features that we see in the more complex animals are, in essence, new.
So, if we say that very early, very simple animals had “tissue” and “skeleton” for instance, then I guess you have the ingredients that you need for “tissue” to become “trachea” and then “lungs.” But, while one can look back in retrospect to see that lungs were merely tissue, once, the entire process still seems to go against the rule of parsimony. It seems that all of the function that did evolve over time should not have been expected to have done so.
This is interesting. So in the whale example above, there seems to be naturally occuring hind limbs, but they are not fully developed and are described as vestigial. These “limblets” seem to be normal (I know nothing about whales, but the thread above seems to indicate such.) So what is the difference between the vestigial limblets shown above and an animal where an atavism occurs? Are you saying that a fully formed limb, rather than a limblet (sorry, my silly term) would be there? Would it be a whale with a true hind leg, flesh and all? Is there a picture of anything like this that can be seen?