Nuts! (gills again...)

In my quotation from Tamara's post, I have added a bit of formatting.Tamara is not repeating her own words; she is quoting from some other unnamed source.Tamara: if you hit the edit button at the bottom of this post, you will see how I use tags. There are various ways to use tags to help show what are not your own words, but quoted from another source.Overuse of tags can make posts unreadable, but a little bit of formatting is a big help. In particular, using the "[ indent]" tag (without the space) is a great way to make a quoted extract stand out from your own text, and would have avoided some of the confusion of others reading your post.Is this really an example of "evolutionist mis-education" in full force? It reads like some badly confused individual; and I'm in favour of being a bit gentle with people who get confused on such details of biology. It is hard to tell if this is worth getting worked up about; no source is given.It would be a different matter if mis-information was present in some formal teaching context, like a text book. There are isolated cases of texts which suggest the notion of embryos recapitulating the adult forms of their evolutionary ancestors; and creationists frequently inflate this to misrepresent any mention of this model as an attempt to teach it. I've seen excellent texts that give completely accurate historical information about this notion of Haeckel, and why it is incorrect, and then give an accurate discussion of evidence for evolution which can be seen in embryonic development. And yet these very texts are still being cited as being part of so-called "evolutionist mis-information" by charlatans like Jonathan Wells in his atrocious Icons of Evolution.In my experience, by far the majority of texts being used in biology explain the "gill slits" or "pharyngeal pouches" perfectly well. I do not think there is a problem about persistent evolutionist mis-information here.In any technical field, there is a problem that students or amateurs get details incorrect from time to time. That is part of learning.So Tamara: what's your point here? Sure, the person you are quoting is confused. You'll find confused individuals all over the place, in any technical subject. Is there something about this instance which is of any significance?If your point is that there might be a few individuals who still manage to repeat Haeckel's long discredited notions of recapitulation in spite of the best efforts of education, then I agree; and I'd encourage you to give a helpful correction, with reference to just about any major biological text to help explain the actual state of affairs.If you consider that there is a deeper malaise in education which actually promulgates such errors, then you need a better example, like an actual text book or lesson plan which makes this error.Cheers -- Sylas

I don't know about that. I'd like to see how one could conduct such a poll without prejudging the answer.Is this really a serious problem? Non-technical persons get horribly confused about the big bang as an explosion and about electrons in orbit around atoms, and lots of other errors in technical subjects.There are plainly problems with basic science education; but I don't think a credible case can be made that people are actually being taught these errors by science educators. There is a problem with people who don't understand a subject, and still make confident and bizarre claims. On the web even the most arrant nonsense can be made to look credible to the uninformed. The situation is greatly worsened in the USA by a religious opposition to science, and an active campaign to portray scientists as close-minded irrational opponents of any valid alternatives consistent with religious beliefs.Scientists have a massive uphill problem with education in the face of concerted idiocy from this quarter.As for gill slits, it seems to me that the errors are resolved by anyone who makes even the most elementary attempt to look at what is actually taught on the subject.All vertebrate embryos have the head forming from what becomes the brain, plus several pouches or arches hanging down that look a bit like gills. This is before there is any facial structure. The arches have several names. They may be called gill slits, or branchial arches, or pharyngeal pouches. The word branchial is from Greek for gills; and reflects their appearance.What happens to these arches? For all vertebrates, the first one ends up by forming the jaw, and the second ends up by forming the hyoid (a u-shaped bone supporting the tongue). The structures also contribute to formation of the face. In fish, gills develop from the third and following arches; and in humans these arches go to make up structures in the throat.Various kinds of branchial development anomalies are comparatively common. They have nothing to do with gills. Many such defects will affect the face or ear; and others may manifest as clefts in the neck, but not remotely like gills. The original author apparent has such a birth defect.Gills are a primitive feature in evolutionary history. There are common embryonic structures which go to make up the face and throat in all vertebrates, which do look a bit like gills in the early embryo, and from which gills are formed in those organisms which have gills in the adult form. Evolution works by co-opting existing structures and adapting them to a variety of environments. The close linkage between gills in fish and the throat in humans is seen in these common embryonic structures, and this a valid part of the multi-facetted body of evidence for our evolutionary origins.For more detail, see Wells and Haeckel's Embryos at talkorigins; it gives the description of the branchial arches and reviews how they are actually taught in text books.Cheers -- Sylas[This message has been edited by Sylas, 02-29-2004]