[_ Old Earth _] Expelled

[Crying Rock]

...they don't use the drawings (and haven't for some time) They use photographs of embryos, which show the same things...

Those aren't Haeckel's drawings. And they actually look like the embryos in question. I repeat, do you have any that use Haeckel's drawings?

http://www.evolutionnews.org/2008/08/ne ... arwin.html


Oh, you want Haeckel's actual drawings? Why? I thought you said: "they don't use the drawings (and
haven't for some time) They use photographs of embryos, which show the same things".

Regardless, does any of this change what is trying to be conveyed as evidence of macroevolution by the textbooks in question? Did you read Casey's comments below each textbook he presented, published in the last 10 years.

The Barbarian wrote:

And you were going to tell me about the phylogenies, based on DNA that had been disproven.

No I wasn't. Casey and these guys were:

Crying Rock wrote:

A list of references were provided:

[2.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009) (emphasis added).

[3.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009).

[4.] W. Ford Doolittle, "Phylogenetic Classification and the Universal Tree," Science, Vol. 284:2124-2128 (June 25, 1999).

[5.] Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009).

[6.] Antonis Rokas, Dirk Krueger, Sean B. Carroll, "Animal Evolution and the Molecular Signature of Radiations Compressed in Time," Science, Vol. 310:1933-1938 (Dec. 23, 2005).

[7.] Carl Woese "The Universal Ancestor," Proceedings of the National Academy of Sciences USA, Vol. 95:6854-9859 (June, 1998) (emphasis added).

[8.] Lynn Margulis, “The Phylogenetic Tree Topples,†American Scientist, Vol 94 (3) (May-June, 2006).

[9.] Antonis Rokas & Sean B. Carroll, "Bushes in the Tree of Life," PLOS Biology, Vol 4(11): 1899-1904 (Nov., 2006) (internal citations and figures omitted).

[10.] Antonis Rokas & Sean B. Carroll, "Bushes in the Tree of Life," PLOS Biology, Vol 4(11): 1899-1904 (Nov., 2006) (internal citations and figures omitted).

[11.] Antonis Rokas & Sean B. Carroll, "Bushes in the Tree of Life," PLOS Biology, Vol 4(11): 1899-1904 (Nov., 2006) (internal citations and figures omitted).

Get to work falsifying the claims made by Casey Luskin.

http://www.evolutionnews.org/2009/05/a_ ... .html#more

The evolutionist, wrote:

I looked at your video. The first thing the creationist from the Discovery Institute claimed, was that Haeckel's drawings are being used in science textbooks to illustrate evolution. What has him infuriated, is that they don't use the drawings (and haven't for some time) They use photographs of embryos, which show the same things....

I'd be pleased to hear from you, of any textbooks in use in the last decade that use Haeckel's drawings as support for his theory. Maybe you could call Casey and ask him where he found his...

He says that textbooks "censor" creationism. They "censor" flat Earth ideas, too. For the same reason. The evidence won't support it.

Where in the video does Casey say textbooks "censor" creationism?

http://www.evolutionnews.org/2009/05/er ... ks_ca.html

 

[Barbarian]

"Censor" is one of the first things he says in the video. Did you watch it?

And I don't see where DNA phylogenies have been overturned in any of your links. Why not tell us about it, and I'll check? If you can't find it in the links either, what makes you think it's there?

I review textbooks from time to time. And I haven't seen an recent ones that don't use photographs of embryos. The photographs work just as well as the drawings, after all. I notice the most recent example of any drawing, much less Haeckel's drawings, the Discovery Institute could find was six years old, and most were over ten years old.

That alone should be a wake-up call, um?

 

[Crying Rock]

Crying rock quoted:

When speaking to the public, evolutionists are infamous for overstating the evidence for universal common ancestry. For example, when speaking before the Texas State Board of Education in January, 2009, University of Texas evolutionist biologist David Hillis cited himself as one of the “world’s leading experts on the tree of life†and later told the Board that there is “overwhelming agreement correspondence as you go from protein to protein, DNA sequence
to DNA sequence†when reconstructing evolutionary history using biological molecules. But this is not accurate. Indeed, in the technical scientific literature, one finds a vast swath of scientific papers that have found contradictions, inconsistencies, and flat out failures of the molecular data to provide a clear picture of phylogenetic history and common descent.

The Barbarian wrote:

And I don't see where DNA phylogenies have been overturned in any of your links. Why not tell us about it, and I'll check? If you can't find it in the links either, what makes you think it's there?

Crying Rock wrote/ quoted:

As the following reference (the first one cited) points out, there are contradictions, inconsistencies, and flat out failures of the molecular data to provide a clear picture of phylogenetic history and common descent (Tree of Life):


“…As ever more multicellular genomes are sequenced, ever more incongruous bits of DNA are turning up. Last year, for example, a team at the University of Texas at Arlington found a peculiar chunk of DNA in the genomes of eight animals - the mouse, rat, bushbaby, little brown bat, tenrec, opossum, anole lizard and African clawed frog - but not in 25 others, including humans, elephants, chickens and fish. This patchy distribution suggests that the sequence must have entered each genome independently by horizontal transfer (Proceedings of the National Academy of Sciences, vol 105, p 17023)…â€Â

Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009)

The Barbarian wrote:

“…your sources I checked was about horizontal gene transfer in prokaryotes. Can you show that there is significant gene transfer in any vertebrate?â€Â

Crying Rock wrote:

See above.

Crying Rock quoted:

“…The problems began in the early 1990s when it became possible to sequence actual bacterial and archaeal genes rather than just RNA. Everybody expected these DNA sequences to confirm the RNA tree, and sometimes they did but, crucially, sometimes they did not. RNA, for example, might suggest that species A was more closely related to species B than species C, but a tree made from DNA would suggest the reverse…â€Â

“…For much of the past 150 years, biology has largely concerned itself with filling in the details of the tree. "For a long time the holy grail was to build a tree of life," says Eric Bapteste, an evolutionary biologist at the Pierre and Marie Curie University in Paris, France. A few years ago it looked as though the grail was within reach. But today the project lies in tatters, torn to pieces by an onslaught of negative evidence. Many biologists now argue that the tree concept is obsolete and needs to be discarded. "We have no evidence at all that the tree of life is a reality," says Bapteste. That bombshell has even persuaded some that our fundamental view of biology needs to change…â€Â

Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009)

The Barbarian wrote:

I think we certainly can show errors in any science, but it would be absurd to deny that the evidence for common descent by DNA analysis is not overwhelming.

Crying Rock quoted:

“…So what happened? In a nutshell, DNA. The discovery of the structure of DNA in 1953 opened up new vistas for evolutionary biology. Here, at last, was the very stuff of inheritance into which was surely written the history of life, if only we knew how to decode it. Thus was born the field of molecular evolution, and as techniques became available to read DNA sequences and those of other biomolecules such as RNA and proteins, its pioneers came to believe that it would provide proof positive of Darwin's tree of life. The basic idea was simple: the more closely related two species are (or the more recently their branches on the tree split), the more alike their DNA, RNA and protein sequences ought to be…â€Â

“…For a while, this allowed evolutionary biologists to accept HGT without jeopardising their precious tree of life; HGT was merely noise blurring its edges. We now know that view is wrong. "There's promiscuous exchange of genetic information across diverse groups," says Michael Rose, an evolutionary biologist at the University of California, Irvine…â€Â

“…This genetic free-for-all continues to this day. The vast majority of eukaryote species are unicellular - amoebas, algae and the rest of what used to be known as "protists" (Journal of Systematics and Evolution, vol 46, p263). These microscopic beasties have lifestyles that resemble prokaryotes and, according to Jan Andersson of the University of Uppsala in Sweden, their rates of HGT are often comparable to those in bacteria. The more we learn about microbes, the clearer it becomes that the history of life cannot be adequately represented by a tree…â€Â

“…More fundamentally, recent research suggests that the evolution of animals and plants isn't exactly tree-like either. "There are problems even in that little corner," says Dupré. Having uprooted the tree of unicellular life, biologists are now taking their axes to the remaining branches…â€Â

“…the Darwinian tree is no longer an adequate description of how evolution in general works. "If you don't have a tree of life, what does it mean for evolutionary biology?" asks Bapteste. "At first it's very scary...â€Â

“…The tree of life is being politely buried, we all know that," he says. "What's less accepted is that our whole fundamental view of biology needs to change." Biology is vastly more complex than we thought, he says, and facing up to this complexity will be as scary as the conceptual upheavals physicists had to take on board in the early 20th century…â€Â



Graham Lawton, "Why Darwin was wrong about the tree of life," New Scientist (January 21, 2009)

The Barbarian wrote:

He says that textbooks "censor" creationism.

Crying Rock wrote:

Where in the video does Casey say textbooks "censor" creationism?

The Barbarian wrote:

"Censor" is one of the first things he says in the video.

Crying Rock wrote::

Where in the video does Casey say textbooks "censor" creationism?

The Barbarian wrote:

I review textbooks from time to time. And I haven't seen an recent ones that don't use photographs of embryos. The photographs work just as well as the drawings, after all. I notice the most recent example of any drawing, much less Haeckel's drawings, the Discovery Institute could find was six years old, and most were over ten years old. That alone should be a wake-up call, um?

Crying Rock wrote:

6 years? Wake-up call? The photographs work just as well as the drawings? What do the photographs work just as well at A theory that is scientifically groundless: the theory of recapitulation?

http://en.wikipedia.org/wiki/Recapitulation_theory

 

[Barbarian]

Barbarian observes:
I review textbooks from time to time. And I haven't seen an recent ones that don't use photographs of embryos. The photographs work just as well as the drawings, after all. I notice the most recent example of any drawing, much less Haeckel's drawings, the Discovery Institute could find was six years old, and most were over ten years old. That alone should be a wake-up call, um?

6 years? Wake-up call?

Yeah. Whipping up on a dead horse. They use photos now.

The photographs work just as well as the drawings?

Yep. Better, in fact.

What do the photographs work just as well at

Demonstrating the similarity of vertebrate embryos early on, and the reworking of structures that would (for example) become gill arches in fish to make ears and jaws in more recent vertebrates.

A theory that is scientifically groundless: the theory of recapitulation?

No. That hasn't been considered a possibility for a long time. But our evolutionary history is confirmed by such events. One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw. Later on, they become relatively smaller, separate from the lower jaw, and become the middle ear bones.

 

[Barbarian]

And now, that is verified by a transitional fossil:

Fossil in China sheds light on evolution of the middle ear

A fossil unearthed in northeastern China has middle ear anatomy somewhere between more primitive and modern mammals, confirming for the first time transitional steps in the evolution of the important structure.

Scientists suspected the malleus or hammer, incus or anvil, and stapes or stirrup, split off from a location at the hinge of the lower jaw to become separate structures.
The new find, 125 million-year-old Yanoconodon allini, has middle ear bones that are partly separated from the jaw, but remain connected by a bridge of ossified cartilage.

 

[Crying Rock]

Barbarian observes:
I review textbooks from time to time. And I haven't seen an recent ones that don't use photographs of embryos. The photographs work just as well as the drawings, after all. I notice the most recent example of any drawing, much less Haeckel's drawings, the Discovery Institute could find was six years old, and most were over ten years old. That alone should be a wake-up call, um?

6 years? Wake-up call?

Yeah. Whipping up on a dead horse. They use photos now.

[quote:ql1selc2]The photographs work just as well as the drawings?

Yep. Better, in fact.

What do the photographs work just as well at

Demonstrating the similarity of vertebrate embryos early on, and the reworking of structures that would (for example) become gill arches in fish to make ears and jaws in more recent vertebrates.

A theory that is scientifically groundless: the theory of recapitulation?

No. That hasn't been considered a possibility for a long time. But our evolutionary history is confirmed by such events. One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw. Later on, they become relatively smaller, separate from the lower jaw, and become the middle ear bones.[/quote:ql1selc2]

I assume you're referring to embryonic development. Have you got an academic reference for this? I'd like to read the details. It sounds like your trying demonstrate the theory of recapitulation is valid.

And now, that is verified by a transitional fossil:

Fossil in China sheds light on evolution of the middle ear

A fossil unearthed in northeastern China has middle ear anatomy somewhere between more primitive and modern mammals, confirming for the first time transitional steps in the evolution of the important structure.

Scientists suspected the malleus or hammer, incus or anvil, and stapes or stirrup, split off from a location at the hinge of the lower jaw to become separate structures. The new find, 125 million-year-old Yanoconodon allini, has middle ear bones that are partly separated from the jaw, but remain connected by a bridge of ossified cartilage.

Will you please cite the reference for this also? This also sounds like your trying demonstrate the theory of recapitulation is valid. However, I don't see anything in your quote that has anything to do with embryonic development.

 

[Barbarian]

Barbarian observes:

I assume you're referring to embryonic development.

Turns out that this is one of those that happens both in evolutionary development, and in utero.

Have you got an academic reference for this? I'd like to read the details.

Hmmm...how about Stephen Gould? I don't have the primary source in front of me, but it's no secret in biology. That's embyrology, of course. Here's the info in paleontology:

http://daphne.palomar.edu/ccarpenter/jaws1.gif

It sounds like your trying demonstrate the theory of recapitulation is valid.

Um, no. Do you know what "recapitulation" means in this sense?

 

[Crying Rock]

Crying Rock wrote:
The photographs work just as well as the drawings?

The Barbarian wrote:
Yep. Better, in fact.

Crying Rock wrote:
What do the photographs work just as well at

The Barbarian wrote:
Demonstrating the similarity of vertebrate embryos early on, and the reworking of structures that would (for example) become gill arches in fish to make ears and jaws in more recent vertebrates.

Crying Rock wrote:
A theory that is scientifically groundless: the theory of recapitulation?

The Barbarian wrote:

…our evolutionary history is confirmed by such events. One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw. Later on, they become relatively smaller, separate from the lower jaw, and become the middle ear bones.

Crying Rock wrote:

I assume you're referring to embryonic development.

…this is one of those that happens…in utero.

Crying Rock wrote:

Have you got an academic reference for this? I'd like to read the details.

Hmmm...how about Stephen Gould? I don't have the primary source in front of me, but it's no secret in biology. That's embyrology, of course.

“…However, the basic idea of recapitulation is still widespread - Stephen Jay Gould's first book (Ontogeny and Phylogeny) begins by declaring that many medical professionals still believe, privately and informally, that there is "something in" the notion…â€Â

http://en.wikipedia.org/wiki/Recapitulation_theory

Stephen Jay Gould, Phylogeny and Ontogeny, Harvard 1985

Here's the info in paleontology:

http://daphne.palomar.edu/ccarpenter/jaws1.gif

Yeah, but we’re talking about embryonic development.

Crying Rock wrote:

It sounds like your trying demonstrate the theory of recapitulation is valid.

Um, no. Do you know what "recapitulation" means in this sense?

In the sense that you’re using the word:

No, humans don't go through evolution in the womb. But our development is constrained by our evolutionary history. So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits make up jaws and parts of our middle ear.

That's how evolution works.

posting.php?mode=quote&f=19&p=445162

Crying Rock wrote:
What do the photographs work just as well at

The Barbarian wrote:
Demonstrating the similarity of vertebrate embryos early on, and the reworking of structures that would (for example) become gill arches in fish to make ears and jaws in more recent vertebrates.

Crying Rock wrote:
A theory that is scientifically groundless: the theory of recapitulation?

The Barbarian wrote:

… evolutionary history is confirmed by such events. One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw. Later on, they become relatively smaller, separate from the lower jaw, and become the middle ear bones.

Crying Rock wrote:

I assume you're referring to embryonic development.

Barbarian observes:

…this is one of those that happens…in utero.

I fail to see the difference between your interpretation and the formal definition of the theory of recapitulation:

“…Haeckel proposed that the gill slits (pharyngeal arches) in the neck of the human embryo represented an adult "fishlike" developmental stage as well as signifying a fishlike ancestor. Embryonic pharyngeal arches, the invaginations between the gill pouches or pharyngeal pouches, open the pharynx to the outside. Such gill pouches appear in all tetrapod animal embryos: in mammals, the first gill bar (in the first gill pouch) develops into the lower jaw (Meckel's cartilage), the malleus and the stapes…â€Â

“…In 1866, the German zoologist Ernst Haeckel proposed that the embryonal development of an individual organism (its ontogeny) followed the same path as the evolutionary history of its species (its phylogeny)…â€Â

“…Haeckel's recapitulation theory claims that the development of advanced species passes through stages represented by adult organisms of more primitive species.[2] Otherwise put, each successive stage in the development of an individual represents one of the adult forms that appeared in its evolutionary history…â€Â

http://en.wikipedia.org/wiki/Recapitulation_theory


“…recapitulation theory ontogeny recapitulates phylogeny, i.e., an organism in the course of its development goes through the same successive stages (in abbreviated form) as did the species in its evolutionary development…â€Â

http://medical-dictionary.thefreedictio ... ion+theory


“…The theory formulated by E.H. Haeckel that individuals in their embryonic development pass through stages similar in general structural plan to the stages their species passed through in its evolution; more technically phrased, the theoy that ontogeny is an abbreviated recapitulation of phylogeny…â€Â

http://www.biology-online.org/dictionar ... ion_theory

 

[Barbarian]

However, the basic idea of recapitulation is still widespread - Stephen Jay Gould's first book (Ontogeny and Phylogeny) begins by declaring that many medical professionals still believe, privately and informally, that there is "something in" the notion…â€Â

http://en.wikipedia.org/wiki/Recapitulation_theory

Medical, who knows. In biology, it's considered a dead idea. Perhaps you don't know what "recapitulation" means. In Haeckel's theory, we become in turn, fish, amphibians, reptiles, etc, complete with gills (for example). This has been refuted.

There is "something" that causes the similarities, but it's modification of existing developmental pathways to new uses, not recapitulation.

(Barbarian notes that this is documented in paleontology and embyrology)
http://daphne.palomar.edu/ccarpenter/jaws1.gif

Yeah, but we’re talking about embryonic development.

Remember the point. This is about the way our evolutionary development can be confirmed by embryology.

Barbarian observes:
One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw. Later on, they become relatively smaller, separate from the lower jaw, and become the middle ear bones.

It sounds like your trying demonstrate the theory of recapitulation is valid.

No. You must learn what the word means.

In the sense that you’re using the word:

Barbarian, earlier:
No, humans don't go through evolution in the womb. But our development is constrained by our evolutionary history. So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits make up jaws and parts of our middle ear.

That's how evolution works. But that is not recapitulation.

I assume you're referring to embryonic development.

Yes. Note that we see the same reworking going on in utero, and in the fossil record. This does not mean that mammalian fetuses hear through jaws, or respire through gills. It merely shows that mammalian structures are derived from those of ancestral organisms.

I fail to see the difference between your interpretation and the formal definition of the theory of recapitulation:

“…Haeckel proposed that the gill slits (pharyngeal arches) in the neck of the human embryo represented an adult "fishlike" developmental stage as well as signifying a fishlike ancestor. Embryonic pharyngeal arches, the invaginations between the gill pouches or pharyngeal pouches, open the pharynx to the outside. Such gill pouches appear in all tetrapod animal embryos: in mammals, the first gill bar (in the first gill pouch) develops into the lower jaw (Meckel's cartilage), the malleus and the stapes…â€Â

Haeckel made a grander claim. He claimed that the branchial arches were true gill arches. They are not, in mammals, and never develop to be so.

In 1866, the German zoologist Ernst Haeckel proposed that the embryonal development of an individual organism (its ontogeny) followed the same path as the evolutionary history of its species (its phylogeny)…â€Â

But it doesn't. For example, we never have gills. You've confused evolution with recapitulation.

 

[Crying Rock]

B quoted:

CR quoted:

However, the basic idea of recapitulation is still widespread - Stephen Jay Gould's first book (Ontogeny and Phylogeny) begins by declaring that many medical professionals still believe, privately and informally, that there is "something in" the notion…â€Â

http://en.wikipedia.org/wiki/Recapitulation_theory

The Barbarian wrote:

There is "something" that causes the similarities, but it's modification of existing developmental pathways to new uses, not recapitulation.

How do “existing developmental pathways†and “the similarities†differ from phylogeny?

Does ontogeny recapitulate “existing developmental pathwaysâ€Â

CR wrote:

Yeah, but we’re talking about embryonic development.

The Barbarian wrote:

Remember the point. This is about the way our evolutionary development can be confirmed by embryology.

By ontogeny recapitulating “existing developmental pathways�

Barbarian wrote:

One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw.

Stunning verifications of what: ontogeny recapitulating “existing developmental pathways�

I assume you think mammals evolved from reptiles. This is phylogeny, no?

And I assume you think bones being arranged as they are in reptiles are part of mammals’ early ontogeny, no?

Recapitulation:

“…the hypothetical occurrence in an individual organism's development of successive stages resembling the series of ancestral types from which it has descended so that the ontogeny of the individual retraces the phylogeny of its group…â€Â

http://www.merriam-webster.com/dictiona ... pitulation


“…the theory that the stages an organism passes through during its embryonic development repeat the evolutionary stages of structural change in its ancestral lineage…â€Â

http://dictionary.reference.com/browse/recapitulation

CR wrote:

It sounds like your trying to demonstrate the theory of recapitulation is valid.

B wrote:

No. You must learn what the word means.

Recapitulation:

“…the hypothetical occurrence in an individual organism's development of successive stages resembling the series of ancestral types from which it has descended so that the ontogeny of the individual retraces the phylogeny of its group…â€Â

http://www.merriam-webster.com/dictiona ... pitulation

“…the theory that the stages an organism passes through during its embryonic development repeat the evolutionary stages of structural change in its ancestral lineage…â€Â

http://dictionary.reference.com/browse/recapitulation

CR wrote/ quoted:

In the sense that you’re using the word:

“…The Barbarian wrote:

No, humans don't go through evolution in the womb. But our development is constrained by our evolutionary history. So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits make up jaws and parts of our middle ear.

That's how evolution works.

posting.php?mode=quote&f=19&p=445162 …â€Â

Barbarian wrote:

No, humans don't go through evolution in the womb.

Agreed. Humans don’t evolve at all, in the macro sense.

Barbarian wrote:

But our development is constrained by our evolutionary history.

Pure conjecture, just like the jazzed up version of recapitulation your claiming.

Barbarian wrote:

So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits…

Why are you bringing up gill slits? Humans never have gill slits. Even you attest to this:

Barbarian wrote:

No, humans don't go through evolution in the womb.

Barbarian wrote:

make up jaws and parts of our middle ear.

That's how evolution works.

I JUST quoted you saying:

Barbarian wrote:

No, humans don't go through evolution in the womb.

Barbarian wrote:

But that is not recapitulation.

Agreed, it’s fantasy.

CR wrote:

I assume you're referring to embryonic development.

Barbarian wrote:

Yes. Note that we see the same reworking going on in utero…mammalian structures are derived from those of ancestral organisms.

Didn’t you just say:

Barbarian wrote:

No, humans don't go through evolution in the womb.

CR wrote:

I fail to see the difference between your interpretation and the formal definition of the theory of recapitulation:

…we never have gills...

Agreed. But you’ve stated differently:

Barbarian wrote:

So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits…

Barbarian wrote:

You've confused evolution with recapitulation.

You’re just plain confused. Macroevolution AND recapitulation are pure conjecture.

However, I did enjoy the tap dance. ;)

 

[Barbarian]

How do “existing developmental pathways†and “the similarities†differ from phylogeny?

Phylogenies are evolutionary relationships. Similarities arise, because evolution procedes by modifying existing structures and functions. If organisms didn't evolve, it would make no sense to use structures which in fish become gill arches, as jaws and ear structures.

Does ontogeny recapitulate “existing developmental pathwaysâ€Â

No. It merely reworks existing things to different uses.

Barbarian observes:
Remember the point. This is about the way our evolutionary development can be confirmed by embryology.

By ontogeny recapitulating “existing developmental pathways�

By modifying existing things to new purposes. Mammals never have gills; the tissues that would form parts of gills in fish are used for other things like jaws and bones of the ear.

Barbarian observes:
One of the most stunning verifications is the development of the mammalian jaw and ear. Early on, the bones are arranged as they are in reptiles, with multiple bones in the lower jaw.

Stunning verifications of what

The way evolution modifies existing structures to new uses. As you learned, the process is documented in the fossil record.

ontogeny recapitulating “existing developmental pathways�

And I assume you think bones being arranged as they are in reptiles are part of mammals’ early ontogeny, no?

They are merely vestiges of what happened before. We still have a reptilian brain below the mammalian one. But that doesn't mean we are reptiles because we have four limbs or a brainstem. It just means that evolution works by modification of existing things.

Recapitulation:
“…the hypothetical occurrence in an individual organism's development of successive stages resembling the series of ancestral types from which it has descended so that the ontogeny of the individual retraces the phylogeny of its group…â€Â

http://www.merriam-webster.com/dictiona ... pitulation

So that means four limbs proves recapitulation? Does this suggest to you the hazards of doing science by dictionary?

…the theory that the stages an organism passes through during its embryonic development repeat the evolutionary stages of structural change in its ancestral lineage…â€Â

http://dictionary.reference.com/browse/recapitulation

So, because mammals and reptiles both form a blastula, that proves recapitulation? Are you serious?

Barbarian observes:
No, humans don't go through evolution in the womb. But our development is constrained by our evolutionary history. So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits make up jaws and parts of our middle ear.

That's how evolution works.

Agreed. Humans don’t evolve at all, in the macro sense.

You've made some progress. Understanding that populations evolve, not individuals, is an important step.

Barbarian observes:
But our development is constrained by our evolutionary history.

Pure conjecture,

Well-supported fact. Sean Carroll, in "Endless Forms Most Beautiful" explains the molecular basis for this phenomenon. Might be the logical next step for you.

just like the jazzed up version of recapitulation your claiming.

And if you learned what recapitulation means in biology, it would help. Your definition would call the formation of a neural tube evidence of recapitulation.

Barbarian observes:
So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits make up jaws and parts of our middle ear.

Why are you bringing up gill slits?

I'm trying to show you that you've confused normal embryonic development with recapitulation.

Humans never have gill slits.

That's what I just told you. Humans don't go through evolution in the womb. But because evolution proceeds by modifying existing things, human embryos look similar to the embryos of other vertebrates early on.

Yes. Note that we see the same reworking going on in utero and in the fossil record. This does not mean that mammalian fetuses hear through jaws, or respire through gills. It merely shows that mammalian structures are derived from those of ancestral organisms.

Didn’t you just say:

Barbarian, earlier:
No, humans don't go through evolution in the womb.

Yes. The fact that we use the same developmental pathways as other vertebrates (albeit modified ones that don't recapitulate earlier forms) is not the same thing as evolving in utero.

I fail to see the difference between your interpretation and the formal definition of the theory of recapitulation:

Well, that is one of the hazards of science by dictionary.

Let's go back to your source, and take a look at a more complete description of Haeckel's theory of recapitulation:
Haeckel's drawings used artistic licence, his theory was associated with Lamarckism, it was quite clearly wrong in supposing that embryos passed through the adult stages of more primitive life-forms...Modern biology rejects the literal and universal form of Haeckel's theory. Although humans are generally understood to share ancestors with other taxa, stages of human embryonic development are not functionally equivalent to the adults of these shared common ancestors. In other words, no cleanly defined and functional "fish", "reptile" and "mammal" stages of human embryonal development can be discerned. Moreover, development is nonlinear. For example, during kidney development, at one given time, the anterior region of the kidney is less developed (nephridium) than the posterior region (nephron).


Barbarian observes:
We never have gills.

Agreed. But you’ve stated differently:

Let's take a look...

Barbarian earlier:
So parts that formed one thing in our ancestors are often changed to form other parts in us. For example, arches that formed gill slits (in fish, instead form other structures in mammal)

It's difficult for me to see how you could interpret that as saying we have gills at some point, even with the editing you did to my statement.

Barbarian observes:
You've confused evolution with recapitulation.

You’re just plain confused. Macroevolution AND recapitulation are pure conjecture.

Macroevolution has been directly observed. As you learned, recapitulation is not a valid theory. You've assumed that the common structures of early embryos are support for recapitulation. They are not.