Haeckel in Biology Textbooks

Could you indulge us by telling us which textbook, by which publisher, in which year? Are you sure they are Haeckel's embryos? Maybe they are, but they may also be modern reworkings of their style to correct the problems with the originals. An example of this kind of thing would be in the Miller and Levine book where they have these rather stylised pictures, in a style similar to Haeckel but rendered from photographs.

I have seen this from Michael Padilla et al., Focus on Life Science: California Edition. This is published by Pearson, which is the parent company of Maskew Miller Longman.Is there some specific element about the pictures in the above, and the associated text, that you object to?

I won't significantly argue with you on it. I don't think they are terrible calamities of accuracy, but there are other more accurate pictures out there that make the same point.This is the 2001 edition and you haven't said otherwise so is this page similar to the one you found in the 2007 book? They do look pretty similar though and what's more the rabbit embryo does indeed look more similar to the human than the fish. A quick look should reveal they are based on Haeckel's drawings. The question is - are the drawings they selected significantly problematic? I'd say they were problematic enough to warrant changing them - especially as I said, given that there are better pictures out there. To the left of the text box there is the following:

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Click (help) next to dBCodes On to find out. You can do it with HTML too, if you prefer - but the dBCodes are easier.As for what embryologists state, I'm not in disagreement. I don't think Haeckel was in disagreement either. From what I know Haeckel was responsible in part for the 'hour-glass' model. Haeckel's diagrams start at the stage he claimed the embryos look most alike and chart things from there.

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Nevertheless, no one
doubts that vertebrate embryos start out looking very
different, converge in appearance midway through
development (though not at the same time), then
become increasingly more different as they continue
toward adulthood - Richardson

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This is in reference to the Richardson paper which was from the other side of embryology: he attempts to show that the hour-glass model is unsupported by the evidence. It's quite a complex paper, but interesting - we discussed here a while ago. No it isn't.If evolution happens, then what changes evolution brings will be expressed during the development stage. We might expect that closely related animals would follow more similar developmental pathways than more distantly related animals.That we see this, is one piece of evidence of relatedness. In the example given, "that rabbits are more closely related to humans than they are to fishes".No need to assume evolution, one merely says 'if evolution is true, what should we expect to see? What observations are consistent with common ancestry?'. If your observations match up with this, you have a piece of evidence of how different animals might be related. Not conclusive on its own, of course.Edited by Modulous, : No reason given.

Well maybe not, but saying it don't make it so. This is just one piece of evidence in favour of the idea. There are others. I don't see what's not clear about that. The similarity does provide one piece of evidence indicating that rabbits are more closely related to humans than they are to fish. You highlight 'ARE' as if it sounds definitive.It is no different than saying 'the fingerprints on the weapon is one piece of evidence that indicates that John Smith is the murderer'. It isn't subtly asserting that Mr Smith did the killing, it's just saying that we have one piece of evidence that indicates that this is the case. Nothing specifically (other than 'fishes' which really should be 'fish' ), it's the kind of language you are more likely to find in a primary paper. However, there is nothing wrong with the wording as is so I guess if they thought about it at all it was a stylistic decision. The wording isn't 'this single piece of evidence proves...' but 'this is one piece of evidence that indicates'. And it is. That you are reading things into the sentence that simply aren't there is more an indication of your own indoctrination than an attempt by the textbook authors to do so. It is not the role of the textbook authors to provide an education, just present the course materials. The teacher actually supplies the lesson, using the textbook as a common reference.Indeed, we'd need to see the whole evolution section of the book to know how it handles it. If it presents several pieces of evidence and says that each provides 'one piece of evidence', before ending on a note like 'on their own, these pieces of evidence are interesting but mostly inconclusive and goes on to say that together, they all point in one direction, they are converging lines of evidence - all indicating that evolution did indeed happen and continues to do so...seems to me to a be a fair way of handling the situation. Well, unfortunately for you evolution is as close to unassailable fact as you are likely to come across. Nevertheless, nothing in the wording in question leads to that conclusion.