[_ Old Earth _] The Non-Evolution of the Appendix

[Asyncritus]

Most evolutionary biologists were taught that the appendix is a 'vestigial organ', a useless remnant from our ancestral past; useless etc etc etc

Unfortunately, that view has been found to be wrong.

Quote:

It contains lymphatic tissue, which integrates with the body's circulatory and immune systems. Researchers recently discovered that it harbors a cache of beneficial bacteria that can recolonize the gut after alimentary trauma.

In contrast, Darwin imagined that it was a useless leftover from a distant evolutionary past.
Darwinists today expect the appendix to appear in animals that supposedly share evolutionary ancestors. But details from a new study on the appendix refute both Darwin and Darwinists.

If the appendix is a remnant from one of our ancestors, then which ancestor was it?

The geneticists have been hard at work, and here is a brief summary of their results. In short, their work has left them stupefied.

Quote: : http://www.icr.org/article/7304/295/

The study authors found the appendix in 50 different mammal forms, most of which they believe to have evolved along separate lines of ancestry. For example, some primates, some rodents, and certain carnivores harbor an appendix, but it doesn't appear in all members of any one of those categories.

[Well. well, well...]

Science Now said about the study, "They found that the 50 species are scattered so widely across the tree [of 361 mammals] that the structure [the appendix] must have evolved independently at least 32 times, and perhaps as many as 38 times."2



Non-evolutionary patterns are the rule, not the exception, for mapping traits onto these trees. Famed evolutionary apologist Ernst Mayr suggested, based on totally different eye designs among fossils, that eyes evolved separately from 40 to 65 times.3

[Doesn't this amaze you about the blinding power of a false theory?]

Some mollusks have eyes like vertebrates, others have unrelated eye designs, and some have no eyes at all.4 Arthropod eye designs are often completely distinct from one another. The mantis shrimp sees 12 primary colors,5 and some lobsters use reflective, instead of refractive, compound lenses.6 Wouldn't a Darwinist expect the first eye to evolve in the supposed ancestor of the aforementioned mollusks or arthropods, and for their descendants to simply inherit that same eye design?

 

[Barbarian]

Most evolutionary biologists were taught that the appendix is a 'vestigial organ', a useless remnant from our ancestral past; useless etc etc etc

Common misconception, that. Since Darwin first explained the concept, "vestigial" (or "rudimentary" as Darwin called it) did not mean "useless." Would you consider reading his book to find out what it actually means?

Unfortunately, that view has been found to be wrong.

More specifically, it's non-existent. Even Darwin pointed out that such structures could serve a different purpose.

It contains lymphatic tissue, which integrates with the body's circulatory and immune systems.

As histologists have always known. However, in many organisms, the cecum was no longer needed (organisms that eat large amounts of low-nutrient food need the cecum for digestion) in those organisms, the cecum shrunk to a mere appendage. Since the rest of the large intestine had more than enough lymphoid tissue, there was no need for it (although it still retained the lymphoid tissue of the cecum).

Researchers recently discovered that it harbors a cache of beneficial bacteria that can recolonize the gut after alimentary trauma.

Actually, they are the same bacterial flora that normally occupy the gut. It's just that the cecum has a different, and less friendly envirionment for pathogens. Interesting to note that it continues to be in the vestigial cecum, no longer a fermentation chamber for leaves, but still serving a purpose.

Darwin would be pleased.

Darwinists today expect the appendix to appear in animals that supposedly share evolutionary ancestors.

You've been misled about that, too. Vestigial eyes, for example, can form in fish, newts, insects, etc. No "Darwinist" doubts that a common organ in any group can become vestigial in different branches of the group. And that's been known for a long, long time. Its no surprise why. Organs require resources to maintain, so if they are no longer needed, they tend to become smaller. But they can still serve a needed purpose.

Famed evolutionary apologist Ernst Mayr suggested, based on totally different eye designs among fossils, that eyes evolved separately from 40 to 65 times.

Seems unlikely since most eyes share the same homobox genes across a good number of phyla. But Mayr, before genetic analysis, wouldn't have known it. But of course, creationists are fond of imagining all sorts of things they just know "Darwinists" believe.

[Doesn't this amaze you about the blinding power of a false theory?]

No kidding.

Some mollusks have eyes like vertebrates, others have unrelated eye designs, and some have no eyes at all.

All of them are more similar genetically and histologically to each other, than to vertebrate eyes. Vertebrate eyes are derived from endoderm, mollusk eyes from ectoderm. There is a difference in the opsins of vertebrates and mollusks, and of course, the genes...

Dual role of transcription factors in regulation of both eye development and differentiation genes.
The box on the left-hand side represents the sum of largely unknown developmental genes regulated by corresponding transcription factors based on functional data. The letters represent different animals (V – vertebrates, A – ascidians, D - Drosophila, C – cnidarians, M – mollusks, P - planarians). The arrows on the right-hand side represent a direct influence of a given factor on differentiation set of genes proved by biochemical methods (DNA-binding assay, ChIP, transgenesis, luciferase assays etc.) The green arrows indicate the ancestral interaction proposed by the “bipartite” model. The red arrow highlights the proposed role of Otx in the regulation of ancestral phototransduction genes. Co-option of certain transcription factor to a new role is indicated by dashed line. We propose that the transcription factors were independently co-opted for regulation of genes governing eye development in different species and these downstream genes may vary among species. Please note that cross-regulatory interactions of transcription factor are not considered in this scheme for simplicity.
http://kozmik.img.cas.cz/eyeevolution.html

At least skim the article; there's a lot of things you probably should know, therein.

4 Arthropod eye designs are often completely distinct from one another. The mantis shrimp sees 12 primary colors,5 and some lobsters use reflective, instead of refractive, compound lenses.

Vertebrates vary widely in the number of colors as well. And as you learned before, every stage in the evolution of eyes in mollusks still exists in living organisms. Likewise in annelids, and many of them in arthropods. Would you like to see that again?

Wouldn't a Darwinist expect the first eye to evolve in the supposed ancestor of the aforementioned mollusks or arthropods, and for their descendants to simply inherit that same eye design?

Given that the evidence shows that they evolve and increase fitness for different needs, not very likely, um?

 

[Asyncritus]

So you agree with me that the appendix did not evolve, and neither does it represent a 'vestigial' organ.

Therefore, it's 'vestigiality' offers evolution no support whatsoever.

The diagrams you have brought forth actually demonstrate that evolution did not occur.

Homology demands that organs be formed from the same parts of the embryo, or they cannot be described as homologous. But as Sir Alistair Hardy said:

The concept of homology is absolutely fundamental to what we are talking about when we speak of evolution - yet in truth we cannot explain it at all in terms of present day biological theory.

Living Stream p213

As you say, :correctly (?)

Vertebrate eyes are derived from endoderm, mollusk eyes from ectoderm.

Those are totally distinct and different parts of the embryo.

Therefore they do not and did not have a 'common ancestor', or they would have developed from the same parts of the embryo: from the same genes, in fact.

Incidentally, Sir Gavin de Beer made a large amount of observations on embryological development and one of his conclusions was:

'Homologous structures need not be controlled by identical genes, and homology of phenotypes does not imply similarity of genotype'

thereby forever ruining the concept of the UCA, and of the validity of homology as a support for evolution.

 

[Asyncritus]

As you've brought up the subject of the evolution of the eye, I have pointed out before, and will do so again now, that your problem (evolution's real problem) is not to produce what looks like a nice sequence of 'eyes' leading from a photosensitive cell to the mammalian eye.

Your problem is to explain what 'seeing' itself really is.

What is it? I am not asking HOW it works, I am asking where the instinctive requirement which powers 'sight' originated.

The photographer, not the camera.

You may produce a series of cameras - from the simple pinhole camera right up to my Leica V-Lux-4 - but that is irrelevant. Your problem is, how did the photographer get there?

He is distinct, entirely so, from the camera(s).

Similarly, the living organism BEHIND the visual structure, 'sees'. How does it know HOW to use its eyes/p-e cells/whatever?

Account for the evolution of the instinct, as I call it.

 

[kevinmaynard]

As you've brought up the subject of the evolution of the eye, I have pointed out before, and will do so again now, that your problem (evolution's real problem) is not to produce what looks like a nice sequence of 'eyes' leading from a photosensitive cell to the mammalian eye.

Your problem is to explain what 'seeing' itself really is.
.

I am not a biologist so much of the discussion of the evolution is honestly unintelligible to me,but I am getting a sense of what I can trust vs not trust for information.

You brought up the eye in your fist post. So why suggest he brought up the subject of the eye in response. That and Presenting a physicist who as far as I could tell didn't say anything about evolution or biology as a biologist who said something is troubling. Who do those things?

 

[Barbarian]

So you agree with me that the appendix did not evolve, and neither does it represent a 'vestigial' organ.

As I showed you, the appendix is nothing more than an evolved cecum, and it is vestigial, because it is no longer used to ferment coarse plant material. However, as you know, "vestigial" does not mean "useless." It merely means that it no longer has a previous function. Our appendix no longer ferments leaves, but it does have some lymphoid tissue, and it seems to now function as a reservoir for our beneficial bacterial flora.

As I said, Darwin would be pleased. He mentioned, in his book, that such organs often evolve to a new function, even after losing the old one.

Therefore, it's 'vestigiality' offers evolution no support whatsoever.

It's just another example of the way evolution works. Nothing is produced de novo; it's always by modification of something already there.

The diagrams you have brought forth actually demonstrate that evolution did not occur.

If you understood them, you would not think so.

Homology demands that organs be formed from the same parts of the embryo, or they cannot be described as homologous.

No, that's wrong, too. For example, the same HOX genes can affect the same cells, but in a different layer of tissue. The evidence clearly shows that these genes can, depending on the initial state of the blastoderm, affect different layers. As you might know, vertebrates are deuterostomes, while mollusks are protostomes. And the shift in tissues affected by the same genes is quite understandable.

If you want to understand why, you might read Sean Carroll's Endless Forms Most Beautiful. It's a very accessible introduction to the science of evolutionary development.

But as Sir Alistair Hardy said:

The concept of homology is absolutely fundamental to what we are talking about when we speak of evolution - yet in truth we cannot explain it at all in terms of present day biological theory. Living Stream p213

That would have to have been written at least thirty years ago. (Barbarian checks) Ah, 1965 the year I entered college. Which would make it um...
48 years old. Long before we understood homobox genes and the way they work. Sorry. Science moves on, and we now understand how that works. Hardy was just wrong.

As you say, :correctly (?)

A half-century is a long time, in biology. But now I understand how you were misled.

Barbarian observes:

Vertebrate eyes are derived from endoderm, mollusk eyes from ectoderm.​

Those are totally distinct and different parts of the embryo.

No kidding. And the layers actually form differently in the blastula of protostomes and deuterostomes. And yet, as you just learned, the same genes work for both of them.

Therefore they do not and did not have a 'common ancestor', or they would have developed from the same parts of the embryo: from the same genes, in fact.

They do arise from the same genes. The genes just act on different layers of the very early embryo. But notice, all of those layers come from a single fertilized cell. Which of the cells that are descended from that single cell, get switched on might vary, but the genes that do it remain the same.

Incidentally, Sir Gavin de Beer made a large amount of observations on embryological development and one of his conclusions was:
'Homologous structures need not be controlled by identical genes, and homology of phenotypes does not imply similarity of genotype'

Sounds a bit unlikely. Show us an example. I'm guessing that Sir Gavin didn't show you one, um? I know why. In fact, he was able to show that some cartilage didn't form from mesoderm, one of the facts that led to the investigations that founded evolutionary development.

thereby forever ruining the concept of the UCA, and of the validity of homology as a support for evolution.

Gavin de Beer disagreed with you. Although he brought up a fact that challenged current thinking on the origin of homologous organs, his work led to the research that resolved the problem, as I showed you earlier.

He did some pioneering work on the embryological evidence for the evolution of the skull, and first proposed mosaic evolution, the notion that change is not smoothly accomplished, but that different parts evolve at different rates.

It's pretty clear that he thought his research demonstrated what you claim it refutes. And since he was an actual biologist who actually knew what he was doing, I'm inclined to go with his opinion.