The Appendix/Cave Fish Eyes/Etc. are (NOT) vestigial

(Ashwin S) #1

I will have to disagree with you there. There are places where the so called “playing fields” overlap.
I hate to say it. But guys like Dawkins certainly think so.

You may think so…let me quote plank Maxwell

A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.

Perhaps Ideas like ID are just waiting for a generation to die out…

I think you misunderstood. I was pointing out that evolution fits all outcomes… i.e no test is really applicable. For example: when the appendix was thought to be a vestigial organ, it pointed to evolution… now that it’s known to have a function… it still points to evolution.
No finding is going to disprove evolution. It cannot be falsified as a system.

That’s true for now. My expectation is that we will face similar problems to that faced in physics once we go deeper in the subject.

Creating Information Naturally, Part 1: Snowflakes, Chess, and DNA
(Matthew Pevarnik) #2

Who cares what he thinks? You and I have both agreed that just because we have a natural explanation for something, it doesn’t mean God can’t be involved or even intervene. You just stop at a certain point in terms of accepting natural explanations.

Who is Plank Maxwell? That’s a rather cynical perspective that this person has, whomever you are referring to and how come a random quote somehow trumps anything that’s ever been written in the past many decades.

I think an interesting case study is with the Steady State theory of Cosmology and Fred Hoyle. He was a firm believer in his idea all the way up until his deathbed, but at the same time, long before his death the entire field of cosmologists virtually stopped publishing on the topic because it does not accurately describe our universe. Sure we can be stubborn people, but as a whole you will find the models that work best and actually make predictions/describe things win out.

No I understood you. And no evolution can be falsified. Like with finding a rabbit in the pre-cambrian era. Or humans with dinosaurs.

Here’s a nice little blog post outlining some ways to falsify it:

I’m sorry Ashwin, you’ve been misled by whichever anti-evolution websites/books/DVDs you’ve been reading/watching. Vestigial organs or genes do not/does not mean they have no function! That is not what a vestigial organ even is. Whoever teaches otherwise does not understand what vestigial structures even are in the first place! NOBODY is claiming they have NO function. They simply have lost some (or even all but not necessarily all) of their original function. I.e. see

Can you have God sending rain in the context of meteorology? Can you have God still influencing the weather to some degree? If not, then why do you reject clear teachings of Scripture that say that it is God who sends the rain? If so, then why can’t you accept that God can be involved in another natural process, the one of evolution?

(Ashwin S) #3

All I said is that I wouldn’t call a process that includes miracles as evolution. I would call it creationism. And I don’t have any problem in believing God does miracles. I think I have mentioned this before also.
Most scientists would gladly agree with this position. Why do you have a problem with it? You yourself admit that science has its limits.
Now if you believe God is involved in evolution as a “purely natural process”, can you describe this involvement? Is it only through laws set up by him?

I’m sorry Ashwin, you’ve been misled by whichever anti-evolution websites/books/DVDs you’ve been reading/watching. Vestigial organs or genes do not/does not mean they have no function! That is not what a vestigial organ even is. Whoever teaches otherwise does not understand what vestigial structures even are in the first place! NOBODY is claiming they have NO function. They simply have lost some (or even all but not necessarily all) of their original function. I.e. see

I didn’t read it in any "anti evolutionary website. This is my source.

The pertinent portion is below:


“Maybe it’s time to correct the textbooks,” says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. “Many biology texts today still refer to the appendix as a ‘vestigial organ.’”

Using a modern approach to evolutionary biology called cladistics, which utilizes genetic information in combination with a variety of other data to evaluate biological relationships that emerge over the ages, Parker and colleagues found that the appendix has evolved at least twice, once among Australian marsupials and another time among rats, lemmings and other rodents, selected primates and humans. “We also figure that the appendix has been around for at least 80 million years, much longer than we would estimate if Darwin’s ideas about the appendix were correct.”

Darwin theorized that the appendix in humans and other primates was the evolutionary remains of a larger structure, called a cecum, which was used by now- extinct ancestors for digesting food. The latest study demonstrates two major problems with that idea. First, several living species, including certain lemurs, several rodents and a type of flying squirrel, still have an appendix attached to a large cecum which is used in digestion. Second, Parker says the appendix is actually quite widespread in nature. “For example, when species are divided into groups called ‘families’, we find that more than 70 percent of all primate and rodent groups contain species with an appendix.” Darwin had thought that appendices appeared in only a small handful of animals.


The guy is clearly stating that the appendix is not a vestigial organ to begin with.

With respect to the article you forwarded on how to falsify Darwinism, i will revert back once I have gone through it.

(Phil) #4

The function of the current human appendix is minimal at best. People do well with theirs, and only would see minimal benefit in case of severe diarrhea, and even that is sort of sketchy as to whether it helps repopulate the colon. I know of no studies that actually show that. Note the ScienceDaily article quoted states the researchers “proposed that it serves a critical function” but offer no studies, no research, no data that supports their proposal is true. In other words, it is just musings, based on the function it serves in other animals.
In any case, he actually does make a good case in the article of it being vestigial, since it has a more important role in other species.
In looking at Google, one of the researchers quoted in the Time article is quoted:
“So what does this mean for people who have had their appendix removed? Luckily, not much. “In general, people who have had an appendectomy tend to be relatively healthy and not have any major detrimental effects,” Smith says.”

(Ashwin S) #5


He is specifically referring to the claim that the appendix is a vestigial form of the caecum. He refutes it by claiming two facts.

  1. there are organisms that have a well developed cecum as well as an appendix.
  2. A large no: of mammal have an appendix and it seems to be over 80 million years old in terms of this origin. Again the question is, vestigial form of what? The facts indicate it’s not a vestigial form of the cecum.
    I found a biology stack exchange discussion that lists the related papers on the subject.

This theory got its first challenge when Parker et al (2007) suggested the appendix to be a safe-house of healthy bacteria when illness (such as diarrhea) flushes them out of the GI tract. It was based on the understanding, which came in 2000s by Sonnenburg et al (2004) and Everett et al (2004), about how the immune system supports the growth of beneficial intestinal bacteria. This was experimentally established when Dunn et al found that individuals without an appendix were four times more likely to have a recurrence of Clostridium difficile colitis.
After this, more functions of appendix were discovered, especially those related to immune system. It is because of the efforts of Zahid et al (2004) (the one you cite) and Rankin et al (2016) that appendix is now identified to be more related to immune system than digestive system in humans.
Also, research by Laurin et al (2011) and Smith et al (2013) concluded that during the evolutionary course, appendix has evolved about 38 times and lost as many as 6 times, suggesting that the cecal appendix has a selective advantage in many situations and argues strongly against its vestigial nature.

My main point was that when scientists found that the appendix was not vestigial, they found evolutionary support for the idea. Just as scientists found evolutionary support for the idea that it is vestigial. This shows a disturbing difficulty to actually falsify evolution in any way. In the future ,if it’s found that vestigial organs don’t exist at all and the entire idea was wrong, it still would not falsify evolution.
That was my main point. Anyway, I am giving the link to the papers if you are interested. The gist seems that the appendix has an immune function which has become redundant in the post industrial revolution scenario… of course such a small time scale should not have any evolutionary significance and so the appendix cannot be termed vestigial.

Edit : @pevaquark : FYIP.

(Phil) #6

I thought, we were talking about the human appendix, not the appendix of animals for which it may have a more prominent and indeed even a different function, UT interesting information nonetheless, so thanks for posting. The possible benefit in C. diff colitis is interesting, as that has only been an issue since the introduction of antibiotics. However, even there, the studies I found showed no difference in the incidence of C diff initially with and without an appendix, though perhaps less problems with recurrent disease. Again mostly speculative, and irrelevant to whether it is considered vestigial, depending on your definition.

(Ashwin S) #7

Is there a functional difference between the appendix of humans and animals? I can’t find any evidence suggesting the same.
Darwin used to think so. However there seems to be no scientific basis for this assumption.

Do you have any reference to any recent study that says the appendix of animals is different from that of humans?
Since the author is talking about convergent evolution, he must be assuming common functional features.
For example, when evolution says that the eye evolved many times, it is referring to an organ that provides the function of “vision”.
I was not able access the paper, so I can’t say definitively. Any light you can shed on the subject is welcome as long as it’s not hearsay.
Edit: I was able to find an article in scientific American that says the function of appendix in animals is also similar to that in humans.
It was good question to ask.

Edit :@pevaquark - FYIP.

(Ashwin S) #8

I have listed the papers published on the subject to @jpm
Pls go through the same.
The function of the appendix in the immune system in both animals as well as human beings is well documented.
It seems it’s the apologists for evolution who have been peddling fake science in this case.

(Phil) #9

Well, certainly suggestive but not well documented. There is even a paper that that finds a lower incidence of ulcerative colitis in people who have had their appy out, so it may be involved negatively as well. As with most human research, confounding factors make it very difficult to tease cause and effect from happenstance. For example, do people who get appendicitis have other problems that make them more susceptible to GI illness or vice versa? Is appendicitis and its removal the cause or the effect or just statistical noise? In any case, you can state with certainty that it is not critical, as most people do fine without it.

(Ashwin S) #10


It’s not just susceptibility to ulcerative colitis. There are other immune system related functions.
There is a role in embryology also which is being studied. I.e it contributes to the immune system during embryo formation/early stages of foetal development.
So, even adults who have had their appendix removed have already enjoyed some of its functional benefits.

You may not like it. But scientists who work in the field have started candidly admitting function to the appendix and denying it’s vestigiality.

That’s a weird statement. Perhaps we should remove the appendix at the foetal development stage and see how critical it is…

Edit: link to a paper showing function of the human appendix in foetal development.

(Matthew Pevarnik) #11

I think the appendix discussion is a little distracting, as again a vestigial organ or gene is the remnant of something that once had more function. I am not sure why you can’t admit that while it may have some function, 11+ million cases of appendicitis say in 2015 with 50,000 deaths is not a good thing! In the US alone we’ve got some 300,000 appendices (plural of appendix lol?) removed each year. A ticking time bomb for many people around the world is yeah, something that may be a leftover from a more useful appendix.

But would you be able to address some of the other questions I had above? It seems that what you believe can falsify the theory of evolution actually tells me that unfortunately you don’t quite understand it-hence why the first article you read on how to falsify had so many disclaimers since many people do not actually understand what they are trying to argue against.

(Phil) #12

Since you mentioned removing the appendix, it brings to mind that not only whether the appendix is functional or not, is not part of whether it is vestigial, but also is irrelevant in medicine, as in modern medicine, you only remove diseased appys. (At one time they took our appys at the time of hysterectomies etc, but that is no longer the case. Not because of loss of function, but due to increased complications due to infection etc due to opening the gut. There is a debate about whether you can treat some appendicitis with antibiotics alone, and that goes to whether it may up later again and cause problem. Anyway, it is interesting, but ultimately off topic. Sorry for the rabbit chase.

(Ashwin S) #13

Cancer happens too… So are cells which develop cancer vestigial?
I agree this is distracting. However since you claimed that saying the appendix is not vestigial is “anti-evolution” etc… I wanted to make the current scientific situation absolutely clear.

For your claim to be valid. You have to prove the below.
That the appendix had an important function that disappeared.

Can you cite papers showing what it was…
As far as I understand Darwin’s argument. He assumed the appendix was a cecum that had become useless in apes and human beings because we consume less cellulose. This does not seem to be the case.

As to evolution being falsifiable. My main point is that it is inherently unfalsifiable.Aspects connected to evolution can be proven wrong (such as neo Darwinism). But not the over arching idea…
Hence I feel it’s more of a philosophy than a theory.
I would love it if you could point to some actual scenarios that would falsify evolution.
Other than rabbits in the pre- Cambrian… with an added disclaimer that discounts all practical challenges.

(Matthew Pevarnik) #14

So a vestigial gene or organ again is one that has since lost its main function or purpose that it once had (all or at least some of it). Cancer would not fit that category at all so no, cancer is not a vestigial gene or organ for human beings.

It seems that the appendix is quite more interesting than I imagined! So I do genuinely thank you for helping to learn more about it. This paper is quite interesting to me and I think relevant for what I want to say next:

That paper suggests 32 independent appearances of the appendix, 7 of which have been lost completely. But out of the 361 mammalian species included in the analysis, only 50 actually have an appendix. If it’s so useful, then why did not more lineages get it and keep it? Certainly though whatever Darwin thought about it was wrong. It’s certainly less clear whether it fits the true vestigial structure as it would be dependent on each species. But…

Who cares what Darwin thought exactly? I mean I get that you are in part arguing against Darwin’s ideas on the appendix which are certainly more complex and nuanced than he could have ever known. He was a smart guy, but I have found this odd tendency for folks to kind of well argue against the theory of evolution based off of what he said over a hundred years ago. As nicely outlined in this blog post:

(Ashwin S) #15

It’s a valid question… I could also ask, if intelligence is so useful, why are there not more species as intelligent as human beings…
If the opposable thumbs is so useful… Etc etc…
I am sure that if you think about it, you can easily formulate an “evolutionary” explanation.
From the creationist POV (which we share , if not in the details)… The basic answer would be …
God created diversity.

The only explanation that I could find for the function of the appendix that was lost was Darwin’s… If somebody else identified the original function of the appendix, that got lost… I would love to learn.


I also think you have the concept of evidence a bit wrong. The whole point is that we inherited our appendix from our ancestors, and that is true whether the appendix has important function or a very unimportant function. We still observe a nested hierarchy of shared features which is what evidences common ancestry and evolution. If humans had feathers that would be evidence against evolution, whether those feathers are vestigial or provide a vital function.

Darwin proposed that organs which fell into disuse would accumulate changes that shrink the size of the organ or cause it to lose the function it had in the ancestral populations. Darwin thought that the human appendix was an example of this process. Whether the human appendix turns out to be a result of this process or not has little to do with the possibility of this evolutionary pathway occurring.

(Ashwin S) #17

Hi T_aquaticus,

I agree. I have already stated that evolution will not be falsified even if all vestigial organs turn out not to be vestigial.

We had to go into this long discussion because @pevaquark was of the opinion that claiming the appendix is non-vestigial was anti-evolutionary nonsense. So I had to establish that there is scientific reason for making this claim.

Things like feathers in human beings happen often in evolution. It’s doesn’t falsify it in any way. It’s called convergent evolution.

(Matthew Pevarnik) #18

Can you show us what it would look like to make God a scientific hypothesis? By what mechanisms does He interact? How can we build models that describe exactly what He does and does not do? When you do this, then it can make sense to call the handiwork of God science.

What are you referring to? We certainly do not spontaneously generate the genes for making feathers. Do you mean atavisms?

This was my main point before. Where do you get this idea from? My point before, asking about vestigial organs or genes is that you have a very similar understanding of them to most anti-evolution literature. Most anti-evolutionists commonly believe and write that vestigial structures cannot have any use/function/purpose. Therefore they use anything that is/was labeled as vestigial, find some potential use, and then write their anti-evolution article. Some may not have any function (i.e. remnants of the GULO gene that cannot make Vitamin C for us- that would be a vestigial gene) but others may have greatly reduced function or have a different function than what they once had. Vestigial structures can certainly be complex but it is a myth that they cannot have any function- that was my point all along. I apologize for confusion of what my main point was.

(Ashwin S) #19

By God, we mean an immaterial, intelligent consciousness that is infinite in nature. Hypothesis can be made involving God.
ID theorists have tried to make predictions of things that result from intelligence being found in nature. Information is something that is demonstrated to arise from intelligence…
So that would be one prediction that is already verified.
The mathematical/logical nature of the universe would also be predicted by intelligence… so that’s another one.
It’s not very difficult.
Immaterial phenomenon such as consciousness interacting with matter would also be a prediction because God is assumed to be immaterial.

I don’t mean Atavism. I was referring to the concept he pointed to… of evolutionary features such as feathers being found in places not predicted by the evolutionary tree. This happens often enough to have a name for it- convergent evolution.

My main point has always been that both sets of facts can and will be explained through evolution. If something is vestigial , it supports evolution. If it is not… then it evolved.
Hence facts like vestigiality or non vestigiality cannot falsify evolution… no fact really can.


There are definitely vestigial features. The toenails on manatees are a good example. The extensor coccygis muscle in the human tailbone spans a fused joint and is definitely vestigial because it no longer lifts a tail as it does in other species. These features are evidence for evolution because they follow the expected phylogeny. You don’t find mammals with vestigial feathers, or birds with vestigial mammary glands, as two examples.

It’s a bit more nuanced than that. Saying that an organ is not vestigial because it has function is usually the anti-evolutionary nonsense we are talking about. No one has ever said that a vestigial feature can have no functional at all. A vestigial feature can still have a secondary or rudimentary function and still be vestigial.

Feathers in humans would not be convergent evolution. Convergent evolution produces analogs, not homologs. The bird wing and bat wing are convergent adaptations, but those wings are obviously not homologous.