In a recent thread here at TSZ the question was raised as to whether naturalism is comfortable with highly typical events. My answer to that question was quite so. Exhibit: the appendix.
Although it is widely viewed as a vestigial organ with little known function, recent research suggests that the appendix may serve an important purpose. In particular, it may serve as a reservoir for beneficial gut bacteria. Several other mammal species also have an appendix, and studying how it evolved and functions in these species may shed light on this mysterious organ in humans.
But wait. There’s more…
Heather F. Smith, Ph.D., Associate Professor, Midwestern University Arizona College of Osteopathic Medicine, is currently studying the evolution of the appendix across mammals. Dr. Smith’s international research team gathered data on the presence or absence of the appendix and other gastrointestinal and environmental traits for 533 mammal species. They mapped the data onto a phylogeny (genetic tree) to track how the appendix has evolved through mammalian evolution, and to try to determine why some species have an appendix while others don’t.
They discovered that the appendix has evolved independently in several mammal lineages, over 30 separate times, and almost never disappears from a lineage once it has appeared.
Evolved independently over 30 separate times! Now that’s right up there in miracle territory if you ask me. I mean, what are the odds!?
For those who have access to this paper, do they really explain how the appendix evolved 30 or more times?
Of course, I’d also love to hear from all the fans of the miraculous powers of evolution just how they think it came to pass that the appendix evolved 30 independent times.
Source:
https://www.sciencedaily.com/releases/2017/01/170109162333.htm
How does my comment reflect my lack of acceptance of evolution?
Allan Miller:
What’s to disagree with or not accept?
And as a bonus, I also accept common descent. But that’s another theory of evolution, isn’t it? And common descent doesn’t explain why the appendix would evolve 30 times, independently, either. So it follows some other theory must explain that. Who can say how many will be needed. Probably at least 30. 🙂
The abstract of the paper says nothing about the claim of 30 separate evolutionary events.
Odd.
Abstract
The evolutionary pressures leading to the appearance of the cecal appendix, its evolutionary relationships with the cecum, and the link between these gastrointestinal characters and ecology remain controversial. We collected data on appendix presence and size, other gastrointestinal characters, ecological variables, dietary habits, and social characters hypothesized to drive appendix evolution for 533 mammalian species. Using phylogeny-informed analyses, we identified the first evidence of a positive correlation between appendix presence and cecal apex thickness, and a correlation with cecal morphology, suggesting that the appendix and cecum may be evolving as a module, the cecoappendicular complex. A correlation between appendix presence and concentration of cecal lymphoid tissue supports the hypothesis of an adaptive immune function for this complex. Other new findings include an inverse correlation between relative cecum length and habitat breadth, and positive relationships between cecum length and mean group size, and between colon length and weaning age.
Trees evolved independently dozens of times too, in many different families and orders of vascular plants. Is that also a miracle?
If you believe blind and mindless processes did it, then yes it would be a miracle.
I’d like to know why you think it odd that it’s not mentioned in the abstract and whether you think Science Daily made up the claim that “they discovered that the appendix has evolved independently in several mammal lineages, over 30 separate times, and almost never disappears from a lineage once it has appeared” out of thin air or whether perhaps they got it from actually reading the paper. Which is more likely, in your opinion?
The paper is free to access- all I did was a bing search on the title of the paper:
https://www.researchgate.net/publication/311535700_Comptes_Rendus_Palevol_Morphological_evolution_of_the_mammalian_cecum_and_cecal_appendix_Evolution_morphologique_de_l%27appendice_du_caecum_des_mammiferes
A minimum of 29 times and a maximum of 41
Could be. But to me “tree” doesn’t bring to mind the same picture as “mammal” and “appendix.” And what’s more, I bet you understand the difference.
In what sense is a tree a trait, John, like the presence of absence of an appendix?
I see that Mung has replied several times, possibly to me. If so, since I have him on “ignore”, someone who cares will have to answer him.
30times!! Hilarious. they have to say that. not only is it absurd but its a common problem of needing convergent evolution to explain bits and pieces in unrelated creatures. Its over folks.
Do primates have the appendix?? Do they use it? Why not if still leaf eaters etc. Why would they noy lose it if a different evolution path has gone on as they say?
Probably the appendix is from the days before the fall or before the flood when people did not eat meat. Possiblt a aid for living eternally on earth.
Try not to muck up the thread. 🙂
If they have no explanation it will soon become apparent. Try to focus on the proffered explanations and how reasonable they appear to be.
And thanks for the link to the paper!
Atheist Sal. LoL!
Another evolutionary theory down the drain. 🙂
What? Why read and respond to the OP if you aren’t interested in the author’s response? 🙄
Well, you see, if trees evolved thirty times independently, then it’s no wonder that the appendix did likewise!
Frankie,
Joe. You claim to understand (have written?) GAs. From random seeds GAs sometimes always converge to a common answer and sometimes provide different answers. Why is that?
Does this explain the independent evolution of the appendix? Evolution is an algorithm that given a different seed converges on the same result?
The appendix is not the only organ to undergo convergence:
http://scienceblogs.com/pharyngula/2006/06/09/penis-evolution/
Mung,
No. It might help understand why Dolphins look like sharks. But I’m just chatting with Joe now if that’s okay.
No offense, but what is your explanation?
Sounds like evolution may not be as improbable as ID requires.
You said that to Frankie?
Keep that up and your status as most intelligent ID proponent at TSZ will be threatened.
Mung:
Patrick:
You said that to Mung?
Keep that up and the calibration of your Intell-O-Meter will be questioned.
Of course, I’d also love to hear from all the fans of the miraculous powers of Intelligent Design just how they think it came to pass that the appendix was designed 30 independent times.
Mung,
No, it isn’t. Think: If an allele sweeps from single copy to fixation, whether by selection, drift or drive (none of which are independent ‘theories of evolution’), what are all the descendant copies, if not commonly descended?
You will doubtless protest that this is within a population, and you’re talking about species. But what, in fact, draws the boundaries of a population, or of an allele?
Any collection subject to this generational winnowing exhibits the same tendency: loss of some lineages, ie coalescence of the remainder.
Mung,
“You accept evolution except where you don’t” can hardly be interpreted to say you don’t accept evolution. Obviously, there is a caveat.
Here’s the subconversation:
A general mutual headshake about those crazy evolutionists and what they believe. Clearly, you accept evolution except where you don’t. And 30 independent origins of a feature is just too much.
Every biological phenomenon is a ‘theory of evolution’.
‘kay.
I’m struggling to understand why something evolving 30 times independently, is somehow more miraculous, than something evolving once. For my own part, I reject the concept of frequency as indication of anything having a miraculous nature.
If it really evolved 30 times, then that would imply there’s a strong selective pressure to evolve it (meaning whatever it does, even if very weakly and inefficient, is still highly beneficial to the organism when and if it works, however crappy), and that the beginning stages are highly probable (which in turn might be due to common descent).
As far as I know, all animals have some sort of digestive system, with a digestive tract wherein a bacterial flora is living in a symbiotic relationship with the host. They both benefit form tmutual cooperation. The bacteria in the gut are protected from the environment and get a steady supply of nutrients, and in return the host benefits from the bacteria breaking down the food so it can be easily taken into the bloodstream. Now, once in a while you might eat something bad, that contains toxins or gives other sorts of digestive issues, at which point the body can purge the digestive tract. Good for getting rid of the bad stuff you ate, bad for your gut flora. Preferentially you’d retain healthy bacteria while getting rid of bad ones, and the bad shit you ate. That’s basically what the appendix does. Serves as a small area where some bacteria can hide from the purges.
And the appendix doesn’t seem to be a particularly complex organ, rather more like a tiny chamber that doesn’t get purged when the gut is, which implies most of it’s evolution involves rather simple manipulations of gut morphology.
So did those mammalian appendices emerge and evolve independently or not? because if they did, I guess they’re not technically vestigial organs, right?
Do they share a single, common ancestor “organ”?
Are you daft? Evolution by design is still evolution. Just because your position’s main processes are impotent and are incapable of the task doesn’t mean evolution by design is also impotent.
There can be a theory of evolution that doesn’t include Common Descent. And if it is to be a scientific theory of evolution is has to exclude Common Descent.
BTW it isn’t up to us to show a boundary exists. It is up to you to support your claims. Your attempt to shift the onus proves that you cannot. So why make the claim in the first place?
ID doesn’t require evolution to be improbable as ID is not anti-evolution. ID argues against blind watchmaker evolution being the sole mover of evolutionary processes. ID is OK with designed to evolve.
Sometimes always- really?
GAs model evolution by means of intelligent design. They are active searches seeking solutions to problems. They have nothing to do with blind and mindless processes
But anyway, sometimes always there is only one solution and sometimes always there is more than one solution.
Really, he should have been talking to you and yours
From the linked paper (just to piss off creos)
Come on Mung, don’t you know, nature just does?
Therefore, I hereby nominate Frankie to the title of “most intelligent ID proponent at TSZ”.
A surgeon once told me I had a blind loop that could be removed. I’m not sure how that’s different from an appendix. I’ve had C.diff twice after antibiotics. The good buggers can hide from purges, but not from antibiotics.
stcordova,
The adaptive mechanism here is generally understood by age 5 in humans 🙂
The paper is a very comprehensive study yet there is one glaring omission. Unless we are talking about Lamarckian inheritance the alleged evolution of the appendix has to be unpacked at the genetic level.
Multiple independent appearances of organs has been fully explained:
Each creature that can see or glow possesses all the required parts for those respective organs and everything is already fully integrated, just as one would expect if God created them. Similarly, the mammalian appendix appears fully formed in those creatures to which God decided to place it.
http://209.157.64.200/focus/news/2998034/posts
That’s a very poor answer. I asked for “answers” not “solutions” – I’m just trying to use precise language which may be beyond you. Why are answers sometimes different, even between runs with the same seed? Do these answers all have the same utility?
Richie, You get answers for questions and solutions for problems. GAs provide solutions for problems. It isn’t my fault the terminology is beyond you.
And different solutions are found for the simple reason more than one solution exists. If only one solution is found then most likely only one exists.
Now you can stop trying to hijack the thread
Mung- Richie seems to be saying that in an intelligent design evolutionary (IDE) scenario, active targeted searches (GAs) can find different solutions and so it is with the appendix. IDE searched for and found all of them as needed.
Frankie,
Focus, Joe: “Why are answers sometimes different, even between runs with the same seed? Do these answers all have the same utility?”
“most likely” is not very scientific.Nor quantifiable. And said by the guy chiding someone else for their lack of precision immediately prior to that.
I don’t know what that means with respect to GAs. GAs actively search for solutions to problems and not answers to questions. Use the proper terminology for accuracy and precision.
If you are saying that different archetypes require different appendix for the same utility- different solutions starting from the same seed- I have no doubt about that. The “one appendix fits all” model doesn’t seem right.
Also seeing that my responses can be trapped in moderation for hours I suggest that you just make your point. This can go on for days and you still wouldn’t have made a case for blind and mindless processes nor will you ever intend to.
So just get to the point, if you have one
Yes, OM, probability has nothing to do with science and cannot be quantified. 🙄
My apologies, Mung, but I couldn’t let that go.
Frankie,
Oh dear. GA folks would see utility as an objective function, like fitness, or as economists use it. Care to try again?
Yeah Richie, stop trying to hijack the thread, can’t you see that’s Frankie’s job?
No, I’m pointing out that your statement was so vague as to be useless.
“most likely only one exists” – that’s not quantified is it? That’s not a specific probability. That’s what we call “an unsupported opinion”. If you would like to provide some actual numbers, as “most likely” is not a number, then perhaps I’ll reconsider.
So Frankie, if you cannot quantify “most likely” then your claim, by your own words, has nothing to do with science.