whirlingmerc
Well-Known Member
Back to @whirlingmerc 's errant claim about humans having "just a skin fold". From the article that I linked:
"This is a half-truth.<in reference to the claim that humans never have gills> While it is technically correct that humans don't ever have gills (since they never function as respiratory organs), humans and other terrestrial vertebrates do have at one point in their embryological development the same structures that in fish and the larva of amphibians become gills.
For example mammals (including humans) and the other terrestrial vertebrates (reptiles, birds) develop pharyngeal (sometimes called branchial, or visceral) clefts and pouches (clefts on the outside, pouches on the inside) in the neck and throat. The only thing keeping them from being true slits is a thin membrane of skin (which in the first pair of "slits" becomes the ear-drums). While these "slits" do not normally open in mammals, they do open, and then close up in amphibians, reptiles and birds. The common creationist claim that the exterior clefts are merely "flexion folds" is totally false. They are the outsides of the "slits" which have corresponding pouches in the throat.
Aortic arches (blood vessels), which travel in between each of the cleft/pouches, also develop in humans and other terrestrial vertebrates. However unlike fish and amphibian larva, terrestrial vertebrates do not develop the finer capillaries (that grow off the aortic arches) that are used by fish to absorb dissolved oxygen from the water in which they live. So we develop the larger "gill" blood vessels but not the smaller ones.
In addition to having the cleft/pouches and aortic arches, the embryos of terrestrial vertebrates also have pharyngeal arches (cartilaginous supports) and nerves which also run in between the cleft/pouches just as they do in the gills of fish. These facts can be found in just about any medical (human) embryology or comparative vertebrate anatomy textbook, and they have been known since before the scientific community accepted evolution."
So human embryos do have pharyngeal arches, which are commonly called "gill slits". These did develop into gills in our distant ancestors though not of course in us.
The look the same... and by faith support evolution
but not a
Hardly. There were some of Haeckel's concepts that were correct. You would throw it all out. Today they hardly use Haeckel except for what he got right. Which is consistent with how other sciences work. When you are taught physics you are not taught that Newton was an alchemist. That huge error in his life is forgotten. There is not enough time to dwell on all of the errors that were made in the past. It takes long enough to go over the successes.
If you could find some of those espousing recapitulation you might have a point. I doubt if you will be able to find any that do that.
In the large, Carl Sagan used the argument to support Harkel and to justify abortion...
and in the big picture was wrong
"In fact, embryos of different kinds of animals are distinct from conception onwards, and modern research has confirmed this."
http://askjohnmackay.com/gill-slits-babies-have-gill-slits-before-birth-proof-evolution/