Why are Haeckel's drawings being taught in school?

Hi Randman,RAZD has already replied, but I'd like to take a slightly different tack. I agree. Everyone would agree. What RAZD actually said was somthing different. He said there are many theories that explain much but not all of the data. The unexplained evidence is not false, it is unexplained. For example, we know relativity theory doesn't apply on scales of the very small. That doesn't make our data about the very small false. It only means it is unexplained by relativity theory. We get by for now by using a different theory for the very small, quantum theory. I think you and RAZD are talking about two different things. RAZD is saying that in cases where we know two species have a common ancestor, we know with absolute certainty that they also at one time had common embryonic development. This is axiomatic, since prior to speciation they were one and the same species.I think you're disputing the "observed fact" portion of what RAZD said, because you characterize it as hypothetical, saying that in reality RAZD has no examples of such cases. I'm not sure what examples RAZD was thinking of, but for me the cichlids come to mind. I can't figure out why you say the opposite is observed. That would mean that we observe that the more closely related two species are, the more different is their embryonic development. But that's not what we observe at all, and I can't believe you'd argue that, for example, the embryonic development of a human being is more similar to a chicken than a chimp, so I must have missed your point. Could you explain this again?--Percy

I agree with much of what you say. The expectation of phylotypic homogeneity for early embryonic development across a broad class of organisms such as the vertebrae was not borne out by research. It appears to be more complicated than that. For example, some studies indicate that the similaries are stronger in the middle of embryonic development.I can agree with what I think is your main point, that scientists erred in believing that embryonic development as understood at the time was another strong and simple independent line of evidence arguing for evolution, and Haeckel shares a good deal of the responsibility for that. The reality perhaps is too complicated for explication purposes.But it isn't bogus, either, just much more complex than originally thought. Increasing morphological similarity yields increasing embryonic development similarity. Creationists argue that similar forms simply require similar embryonic development, but this point fails because increasing genetic similarity yields even greater increasing embryonic similarity than morphological similarity, and this is extremely strong evidence for evolution.Touching on the thread's topic, Haeckel's drawings shouldn't be taught any more. They're hopelessly out of date, they do not communicate our current understanding.--Percy