Haeckel in Biology Textbooks

Here's a working version of the link again: Since Randman can no longer post in this forum, I think it is incumbent upon me to be his representative. Obviously I'm unworthy, but I shall do my best. Ahem. Getting into character, give me moment...okay, here I go...

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This is just the same evolutionist whitewash we always see. Evolutionists indoctrinate children by including Haeckel's fraudulent diagrams in modern textbooks, even though they've been known to be fabrications for over a century. Randy Olson is a liar and a hack for claiming otherwise, as is demonstrated by this video: If you evolutionists weren't so caught up in your own illogic and intellectual dishonesty you would see how wrong you are, because the lies of Haeckel are still perpetuating the myth of evolution today.

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It's been released (see Flock of Dodos: The Evolution-Intelligent Design Circus), so I'm going to see if I can find 'Flock of Dodos' playing anywhere, it sounds like fun. Apparently it makes an important point. The dodos it's referring to are evolutionists, since they seem unable to effectively respond to the threat of creationism, winning legal points in court but badly losing the battle for public opinion, a point effectively made in this NPR interview (click on the "Listen" link on the webpage): Perhaps an equally appropriate term is ostriches, since there's a tendency on the part of many scientists to believe that they can hide their heads in the sand and creationism will just go away.--Percy

This is a reply to Beretta's Message 46 in thread Icons of Evolution. You're still getting this wrong, because the exact opposite is the case. The earlier the embryonic stage, the more similar it is to other species.Haeckel made two mistakes. The first was in thinking that the course of embrylogical development retraces a species evolutionary history. This is true in a general sense, as many have been pointing out to you in the other thread, but not to the extent Haeckel thought. Embryos do not pass through the adult stages of organisms from their evolutionary history.Haeckel's other mistake was in fudging his drawings to make it seem that embrylogical development retraced evolutionary history more closely than is actually the case. I don't think Haeckel was desperate about Darwin's theory, he had no personal stake in it himself, but his embryological discoveries were in reality very supportive of evolutionary theory. For instance, during embryological development in mammals, what starts out as bones in the jaw and actually do become part of the jaw in fish and reptiles migrate to becomes bones of the inner ear. This is because fish and reptiles are the evolutionary ancestors of mammals. I'm curious where you're drawing this information from. How about you tell us why you keep repeating things that are not true. If you ask anyone who accepts evolution to list the reasons why they do, Haeckel will not be among them. In fact, many accepting evolution probably know very little about Haeckel unless they've gotten involved in discussions with creationists, the only group expressing any intense interest in Haeckel in more than a century.--Percy

As Dr. Jack and others have been telling you, this is wrong. The earliest stages of embryonic development are the most similar across species. The precise period during which they're most similar is called the phylotypic stage, described here in the textbook Principles of Developmental Biology: You can see why it almost has to be this way if you think about it for a minute. Would it make sense to you if chicken and human embryos started out very different and became more and more similar during development? Of course not. I can't find the quote either, but I found something that mentions it at the National Center for Science Education's website, see Haeckel's Embryos. Jonathan Wells evidently quoted from the sixth and last edition of Darwin's Origin of Species where Darwin laud's Hackel for his work on phylogeny, not embryology. The book predates Haeckel's embryological work by a number of years but has a chapter noting the similarity of embryos across species in early development stages. Also, Darwin's Descent of Man contains two embryological drawings, neither from Haeckel.But this is all just trying to set the record straight. Independent of Darwin's opinions on Haeckel's embryo work, the earlier stages of embryonic development *are* more similar across species than later ones. I don't know where your error in thinking the opposite comes from, but error it clearly is.--Percy

This thread is about Haeckel's embryo drawings, and Haeckel was not focused on the "earliest stage" of embryonic development. Haeckel's drawings are not of the "earliest stage". They're all of embryos that have developed beyond the phylotypic stage.The "phylo" portion of "phylotypic" derives from the word phylum. "Phylotypic stage" is a stage of embryonic development where it is common for embryos of animals of the same phylum to most resemble each other. Here is a set of Haeckel drawings illustrating multi-species embryo development: Every organism in the top row, from fish to salamander and on across to human, already has a spinal chord (because they're all in the chordates phylum), so they are all obviously beyond the phylotypic stage.In other words, Haeckel is silent on what you're calling the "earliest stage" of embryonic development, so it's not possible that he could be lying or fraudulent about it. If you're truly focused on this "earliest stage" prior to the phylotypic stage then you cannot be talking about Haeckel's embryo drawings. If you want to discuss earlier stages of embryonic development then you really should be posting to a different thread, or proposing a new one.--Percy

Animal embryos begin as a single cell and then become two cells, four cells, eight cells and so forth, and over the next few days become a blastocyst of maybe a hundred or so cells. Inter-species differences during this stage cannot be great. In humans this stage is reached around day 5, and the phylotypic stage is reached around day 20, which is from 2% of gestation up until 8% of gestation. So your claim is that inter-species embryonic differences are significant between 2% and 8% of the gestational period. This seems unlikely given the short time period, the presence of few structures, and the small number of cells involved, but your welcome to try to support your position. Where did Haeckel ever claim that his drawings in the top row represented the earliest stage of embryonic development? This is something that you've failed to demonstrate yet. The textbook Principles of Developmental Biology says (and you quoted this yourself), "They are more similar to each other during the phylotypic stage than during earlier or later times of development." That the phylotypic stage is the point at which they are most similar does not support your claim that they are "very different" prior to that point.The fact of the matter is that they are very, very similar, and I suspect that many would beg to differ with the textbook's description that the phylotypic stage is the point where they are most similar. Remember, that page is a summary of the chapter 's contents and was necessarily glossing over details. Since "phylotypic" is based on "phylum", the point it was most likely trying to communicate is that the phylotypic stage is the stage where embryos are most similar with respect to signature phylum characteristics, like spinal chords for chordates like ourselves. Anyway, embryos not much beyond the "clump of cells" stage don't have many significant ways in which they can differ. If you think they're significantly different prior to the phylotypic stage you'll have to demonstrate this. It is true that Haeckel's theory that embryological development represented a rather precise recapitulation of evolutionarily earlier adult forms was incorrect. We all agree on that, and this never became an accepted view within science anyway.What is true is that embrylogical development across different species has many shared characteristics that are reflective of a shared evolutionary history, and any photographs or diagrams of equivalent embryonic stages across different species very effectively make this point.--Percy

That's all very interesting but seems to have nothing to do with Haeckel in biology textbooks. Unless I misunderstand, what you wrote and quoted was about the stages from the bonding of sperm and egg up through cleavage and gastrulation, and Haeckel's drawings were all of stages after that point, so I again think you're posting to the wrong thread. Why don't you propose a new thread, and you can include Jonathan Wells' claims that Darwin and Haeckel believed that evolutionary theory predicts that the very earliest stages of embryonic development should be the most similar.In the Chapter 13 (Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs) of the Origin of Species is a section on embryology, and in it Darwin states that he is skeptical of the views of Agassiz that are eerily similar to those Haeckel proposed a decade or so later: In other words Darwin says that while he hopes it will be shown true and clearly understands it would be supportive of his theory, he doesn't think it likely, and he definitely makes no claim that evolutionary theory predicts that this is what we should see.--Percy

The accusation against Haeckel is that he drew false representations of embryos to make them appear more similar than they really were. That these drawings may still appear in modern textbooks is the topic of this thread.You're offering a totally different and weird accusation that has Haeckel trying to hide the fact that embryos with eyes and tails do not represent the earliest stages of embryonic development, and you contend that embryos in the earliest stages are very different, that Haeckel knew it, and that he was trying to hide that fact, too. If you really want to pursue this totally odd idea, which apparently originates with Jonathan Wells, then I think you're right, you should probably do it back in the original thread, Icons of Evolution.--Percy

Where are you getting your information about the "actual appearance". Please point us at this information. You can find tons of pictures of early embryos on the web, and across many species they are broadly similar - a curled up fishlike creature with eyes and tail. You can send it to me at Percy and I'll make it available so you can include it in messages. Not at the phylotypic stage they're not, which is what is depicted in the top row of the image in that textbook.You're in a battle against reality. The criticism of Haeckel is that he made already very similar embryos, nearly identical to the uninformed eye, look more similar than they really were. You're trying to argue that what look like curled up tadpoles are actually significantly different. Good luck with that. The phylotypic stage is not the midpoint. In humans the phylotypic stage occurs at about 20 days, about 8% of term and about 4 months shy of midterm. While the time of the phylotypic stage as measured percentage-wise will vary across species, it definitely is way before the midpoint. Except that the first stages are not very different, they're extremely similar. For example, how different can the very first stage, a single fertilized cell, be? Some embryos will be attached to yolks, some to placentas. Some will be larger, some smaller. These are superficial differences. That many very early embryos can be observed going through the same stages of cleavage, blastocyst, and gastrulation is more evidence of their similarity.But though it is not true that embryos before the phylotypic stage are significantly different, it is true that there is less similarity than at the phylotypic stage, and this is because of the requirements of reproduction that can cause the initial conditions to vary so widely across the various species types. Yolk versus placenta for providing nutrients is just one of the more obvious examples of different initial conditions.--Percy

Maybe it will help to put the pictures on the same page, so here we go.Chick embryos: Mouse embryos: Human embryo at 30 days: AbE: It looks to me like the chick at 15+ days, the mouse at 9.5 days, and the human at 30 days are most similar.--PercyEdited by Percy, : Add information about days.

You know this stuff pretty well, so can you do what I would have liked to have done, which is to post chick, mouse and human embryo pictures from the same stage side-by-side, annotated with the number of days *and* the percentage of full term?--Percy

About Richardson's embryo series, a couple questions.In the top row, what are the large bulbous masses attached to some embryos? Are these a yolk or some equivalent?About the top two human embryos, they're unrecognizable, not only as human but even as embryos. Shown these micrographs out of context I probably wouldn't guess they were embryos, let alone human embryos. In the top one there's no discernable head or tail, while in the middle one I might guess that the bottom structure is a tail, but more likely if someone just handed me that picture and asked me what it was I'd answer, "I have no idea." Primitive sonograms look more human than those micrographs. I guess I'm just very surprised that these two micrographs are so unrecognizable. Something seems very "off" about them.I have to be honest and say that my untrained eye could not use the Richardson series to argue that embryos are more similar at earlier rather than later stages. In fact, the fish seem more similar late than early. I assume a trained eye is necessary to identify the relevant features and note the ways in which they are similar early and describe their growing dissimilarity with development, so maybe someone would like to attempt this?--Percy

Regarding the human embryos, yes, the hi-res version helps a little. The top human embryo now looks like an embryo, though if presented to me out of context I would have guessed a grasshopper after being pulled from an acid bath. The middle embryo just looks like a muddle to me, though.But the more important issue for me is how one would use the Richardson micrographs to argue that embryological development indicates a shared evolutionary history.--Percy

In Message 56 Beretta repeats his claim that Haeckel used artistic license to make embryos across different species appear to have shared characteristics at early stages of development when they do not. He further believes that this is the foundation for much modern acceptance of evolution. He makes a couple other claims that border on the tendentious and even silly, and I'll leave those aside.Haeckel's theory that embryos pass through the adult stages of evolutionary ancestors was false (and sounds incredibly weird to modern ears anyway), and there is evidence that some of his diagrams brought out certain features more clearly than visual evidence would support, but at early stages embryos do possess many common features and development paths that strongly support the conclusion of a common evolutionary history. However, we're finding it very difficult to support this position in an Internet discussion board environment.So I thought I'd see what photographic evidence existed on the web for just one feature, gill slits. Here's the Richardson photograph series that Wounded King posted: I could find no gill slits, but Wounded King supplied a high-res version, and looking at this I think I can discern gill slits in the salmon, the bat and the cat in the photographs in the top row. That's only three out of thirteen. And it does seem somewhat odd to me that I thought I could make out gill slits in more mammal embryos than fish.So is there any photographic evidence on the web that all, or at least most, embryos have gill slits at a very early stage? Demonstrating this seems the minimum requirement for embarking on a rebuttal of Beretta's claim.But even if we find the gill slit evidence on the web, or make it available on the web, a single line of evidence does not a successful theory make. Is there any photographic evidence of other common features? The fish jaw bones that eventually become mammalian middle ear bones perhaps?--Percy

Beretta seems to be on sabbatical, so let me try to argue things from his side.The photographs of chick, mouse and human embryos in my Message 52 do not seem to contain any similarity at the location of the pharyngeal arches. For the human embryo, at the location where these would be are three small bulbous masses (labeled 1b, 2 and 3). At no stage does the chick have any such bulbous masses, and at stage 9.5 the mouse has one. Regarding this one feature I see only slight circumstantial evidence of a similarity between mouse and human, and no similarity at all of the chick with the mouse or human.If I were Beretta I might say that biologists are seeing what they want to see, and I also detect strong hints of a desire to just declare the battle won on this front so they can move on to other less embarrassing evidence.--Percy