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
What is different about the various appendixes that have evolved then? Remember, you have no doubt about that so you must have a reason for that lack of doubt.
Frankie,
Sure there can. That’s not this one, though. This isn’t “a” theory of evolution – such as, for example, the ID bollocks you peddle – it’s “the” theory of evolution!
WTF?
If you assert there is a boundary with no further reasoning beyond ‘there is’, I don’t need to do anything.
There is a tooth fairy. It isn’t up to me to show it exists, it’s up to you to support your claims with respect to it.
I wasn’t shifting the onus on anyone. You popped up in response to something I’d said. I was not importuning you.
[eta – If one is a baraminologist, which Frankie appears to espouse, one accepts inter-species common descent anyway, so I don’t know what he’s complaining about.]
The world not taking him seriously in 60+ years?
And if it is to be a scientific theory of evolution is has to exclude Common Descent.
It is an untestable claim. And because of that outside of science
BTW it isn’t up to us to show a boundary exists. It is up to you to support your claims.
If you assert that you have a process that can produce such a thing then you need to demonstrate it. If you want to make a claim you have to support it. It isn’t up to us to show there is a boundary. It is up to you to show that you have a mechanism capable of doing what you say.
Two different things- The common descent of baraminology does not include humans and chimps sharing a common ancestor, nor does it include hippos and whales sharing a common ancestor.
Oh dear- GA folks wouldn’t ask about answers, they would ask about solutions.
Try again.
He’s saying common descent isn’t testable science, even if it takes place only within kinds. [assuming your premise is true]
I guess that is one of the reasons I accept common descent. I came to understand that even young earth creationists accept some form of common descent. And if you accept it within “kinds,” why stop there?
Are you saying that the theory of common descent is “the” theory of evolution? Because I see it as a separate theory from what you outlined in your OP that I quoted.
So I accept the theory of evolution according to which allele frequencies change and I accept the theory of evolution aka the theory of common descent.
So that’s at least two theories of evolution I accept.
What theory of evolution explains the independent evolution of the appendix, thirty or more times? Because if your theories don’t explain the phenomena, they fail as a theory.
What do folks think of John Harshman’s argument that trees are like appendixes when constructing phylogenies? He has me on ignore because I have the gall to challenge his claims (he’s an expert). Maybe he’ll explain it to someone else.
There’s no doubt in my mind that Salvador is far more intelligent than I. But I manage to compensate. 🙂
[Assuming Sal’s an ID proponent, something I doubt, lol.]
Don’t you think that your theory ought to answer these questions?
Human family trees, ie common descent, is testable. Placing humans and chimps on the same family tree, Common Descent, is untestable
Well, they appear to believe in miracles. That’s all I’m saying.
I don’t know in what sense you are using the term evolution. Thirty independent sort of rules out the theory that the feature is shared due to common descent, right? So if common descent doesn’t explain it, what theory does?
It just happened, that’s all, is not a scientific theory.
Good point. But if it happens once people call it an accident. If it happens repeatedly, not so much. Why was it called out in the paper of three’s nothing remarkable about it? Didn’t “the theory of evolution” predict it?
I think most people would not classify things that happen all the time as miraculous. But I’m sort of with you here. Miraculous happens all the time and we just fail to take notice due to its frequency.
There is no such thing as a strong selective pressure for something that does not exist. This option is just not available to evolutionists in the current theory. Not in the toolkit. That’s teleology.
Even if we grant to you that some beneficial feature was shared by common descent, and even if we grant that the beginning stages are highly probable, it would also need to be the case that the subsequent stages also needed to be highly probable, else there’s no reason for the convergence across multiope lineages.
Further, if we accept your first two propositions, what happened in the cases where an appendix did not evolve? The theory needs to explain both the presence and the absence.
They didn’t evolve completely independently. Since 2009 Heather Smith and her colleagues have published multiple papers on the evolution of the cecal appendix. Many of the features they identify as an appendix seems to be really stretching the definition. PZ Myers had a good write up on the issues back at Pharyngula in 2009.
Evolution of the appendix?
Caption: The tree on the left is using the strict definition of an appendix, and the one on the right uses the broader definition. Taxa that have an appendix are in red, taxa in which there is a mixture of species with and without an appendix are in blue, and those without any appendix at all are in gray.
Nah, he’s just focused on becoming the next Duane Gish, regardless of how many children he has to abuse to get there. He’s not smart enough to realize the scam has mostly run its course and there’s no pot of gold at the end of the rainbow.
You, though, are an intelligent design dilettante. Don’t sell yourself short.
Mung,
In the same sense I use it whenever I precis the theory: genetic change (inc: mutation, recombination, LGT) in reproducing collections (populations or broader taxonomic groups) winnowed by the generational sampling process (inc: selection, drift).
I don’t really see common descent as a ‘theory of evolution’, so much as a corollary of it. I think there is often a confusion of process and history. Common descent is not a process, but the result of a process.
But essentially, if an appendage is useful to an organism that doesn’t have it, and there is a path by which it can be gained, then it is reasonable to assume the ‘selection’ part has a role to play. It doesn’t need any new theories of evolution. It just needs the same basic thing to happen more than once.
If we find it unremarkable to happen once, happening twice hardly seems a major hurdle, given that one may postulate a generalised selective advantage driving the 1st occurrence. Advantage is not a single-use kind of thing. This is why we get multiple instances of eyes, teeth, legs, multicellularity, etc – if we may speculate, not unreasonably, that the advantage is broadly the same in each case.
Actual selection requires intelligence. Natural selection is a process of elimination and doesn’t help you.
If evolution is teleological Allan has a point. But if it is blind and mindless he doesn’t.
“There’s no doubt in my mind that Salvador is far more intelligent than I.”
Salvador has already figured out ID is a scam.
The opening line of the abstract:
What is an evolutionary pressure leading to the appearance of [insert evolutionary goal here] (such as the appendix)? It literally makes it sound like if there’s an “evolutionary pressure” for eyes, eyes will appear.
Now as a theist, I can understand that a process might be biased towards specific outcomes by design, and if that’s how evolution works, I am all for it.
Speaking of the miraculous:
http://www.asbmb.org/asbmbtoday/asbmbtoday_article.aspx?id=48961
No design(er) is responsible for the bias, it’s the environment. Reality doesn’t give a fuck for your theism or what you’re ok with
Do you think that’s a scientific, testable claim, dazz?
How do we test whether an environment is biased towards the production of an appendix in some mammals but not in other mammals?
Precisely how many “environments” are there and how do we distinguish one “environment” from another?
It’s a nice thought, but it’s not science. Frankly, I find it hard to tell how it’s any different from goddidit.
Mung,
No, we know God didn’t do it because we know descent with modification did it, and we have every reason to believe that natural selection was involved because we can empirically test NS and we know it works.
Just like we don’t need to know every microscopic step in the process of formation of the Moon to have every reason to believe that gravity did it.
You begin to sound like Bill Cole, are you feeling the urge to go full retard or something?
It is possibly testable, goddidit isn’t.
Unfortunately for dazz no one can test the claim that natural selection produce any appendix. For one they don’t even have a mechanism that is capable of producing the organisms who have one.
Baldly declaring NS didit is not science. You have to have a way to test the claim and as of today you don’t.
“Miracle is a 2004 American sports docudrama about the United States men’s hockey team, led by head coach Herb Brooks, portrayed by Kurt Russell, that won the gold medal in the 1980 Winter Olympics. The American team’s victory over the heavily favored Soviet team in the medal round was dubbed the Miracle on Ice. Miracle was directed by Gavin O’Connor and written by Eric Guggenheim and Mike Rich.”
It was intelligently designed is testable whereas NS didit is not.
Yeah and “Supernatural” is a Grammy Award winning album/ CD by Carlos Santana
I can’t say I’m in the least bit surprised, but the paper does not tell us how the appendix evolved even once, much less 41 independent times, nor why.
But the faithful seem satisfied that their theory, which doesn’t explain the phenomena, is better than the alternative [which also doesn’t explain the phenomena]. Somehow.
You don’t know how or why the appendix evolved independently “possibly as many as 41 times, throughout mammalian evolution” but you know that it did. Somehow.
No, dazz. Common descent does not cause anything to evolve. Common descent may explain why all mammals have an appendix, but all mammals don’t have an appendix. And common descent doesn’t explain that.
And following your reasoning, since you don’t know that common descent did it, you don’t know that God didn’t do it.
Common descent does explain why all mammals have similar digestive tracts which function is similar ways where evolving an appendix in a species’ particular environment would be a selectable advantage.
I said descent with modification: we know they share a common ancestor, we know they’re different, including their appendices, it follows then that they were progressively modified along the way because we know fully formed organs don’t appear out of the blue in the reproductive process. And we know how organisms are modified generation after generation by means of mutation, selection and drift. That’s more than enough to rule out “design”, how would you propose the designer could intervene in such a process? It makes no sense whatsoever
And what kind of “explanation” are you looking for? you want to know exactly what the selective pressures were like millions of years ago for each lineage? perhaps you want to know every single mutation that led to the formation of the appendix of each of the species? That’s fucking ridiculous.
Claims of common ancestry are not testable and therefore outside of science. If all Common Descent can do is explain the similarities, which is all it can do, then it is impotent as it needs to explain the anatomical and physiological differences observed, which it canot
Yes there is, this is a common mistake. There can’t be strong differential reproductive success without variance, but IF that variance crops up, it will be hugely beneficial.
Evolution has no foresight, but that means there is no guarantee the right mutations pop up for that thing that would be beneficial, if the they did. But this is not the same as saying there can’t be a selective pressure for something that doesn’t exist.
For example, fish that are slim. If all fish were fat and bulky (meaning no fish were slim and “torpedo shaped”), any mutation that happened to make the carrier fish a bit more slim would be highly advantageous due to reduction of hydrodynamic drag. This is an ever-present selective pressure of life in water. Anything that moves in water expends less energy if it experiences less drag. So either it has a lifestyle where it moves very little (sits in a cave, camouflaged, or lurks in silt on the bottom), or it is slim. That selective pressure will always exist in water. This isn’t teleological, it’s an intrinsic property of the environment.
Well of course not. Mammals are special, they’re like you. Trees are just, you know, life.
Yes. The scenario I described pretty much explained all that. Just look at what we already know, we can extract a scenario for the evolution of an appendix-type structure from first principles.
Basically all animals have a digestive system of some sort. And that digestive system is, essentially, a long tube. In this tube live bacteria. This is of benefit to the bacteria, and to the animal. The bacteria break down nutrients and keep some of it for themselves, what is left over can be very easily taken up by the animal host, because the bacteria already did a lot of work breaking it down. The bacteria are protected from the environment while inside the host. It’s a win-win for both parties most of the time.
We also know that animals some times eat stuff they can’t digest. Maybe it’s insoluble, or it takes up a lot of water and becomes hard, or it might even be toxic. If that happens, the animal has a reflex that purges the “tube” for this indigestible material. This is bad news for the bacteria living there, because they’ll get purged out too. Which in turn is bad news for the animal host, because it fares much better when it has a good supply of healthy bacteria of the right kind for reasons already detailed.
What is the appendix? It’s sort of a small chamber where the bacteria can “hide” and survive when the digestive environment is bad for them. Either because of those purges that flush them out, or maybe in periods of starvation.
So if an organism doesn’t have an appendix, a chamber were the bacteria can hide, it’s at a disadvantage compared to one that has. Does such a chamber have to be “perfect”? Not really. Even a small indentation or crevice where some few healthy bacteria can hide, during a purge, is better than NO place to hide. For both parties, the bacteria and the host. This, when we think about it, seems to be a universal truth for anything with a digestive system with bacteria in it, which will occasionally eat something bad it can’t digest that triggers a purge.
So, if there should ever be an individual born, with a mutation that causes there to be such a tiny crevice, that individual will have an advantage. Is a tiny crevice as good as a full-blown appendix? No. Fewer bacteria can hide there, and it still some times gets purged if the expulsion is very violent or whatever. So organisms with the tiny crevice do better than those without it, and those with a slightly bigger, deeper one do better than those with a tiny one (and even better than those without it entirely). And so on and so forth. There’s clearly a selective pressure all the way from no appendix, to a full-blown, bona-fide appendix.
Sure, and two options seem to present themselves. Either the organisms without an appendix have a different kind of diet and lifestyle that makes it’s presence superfluous (maybe their gut bacteria have evolved some other coping mechanism to avoid purges? You’d have to look into that of course), or they’re just among the lineages that didn’t suffer the right mutations. After all, just because something would be beneficial doesn’t mean the right mutations will happen to everyone and everything. Yes, here the explanation might essentially be that much dreaded concept: chance. As a matter of chance, while an appendix is beneficial, not every lineage got the right mutations. I can already hear creationist heads exploding.
+1. Intentionally obtuse abuse of language is arguably the most defining characteristic of the disingenuous.
Mung,
And therefore talking shite, as usual. Do you go along with this? Despite having many books on your shelves, there is no method one can apply which can elucidate the claim of common descent? Bearing in mind that this is routine – as has been discussed before – in genealogical and forensic testing?
On what basis does one decide that common descent of – say – those Sandpipers I regularly bring up as my ‘type species’ – is not ‘scientifically testable’, when the relationship of a forensic sample to its source is?
Aha!!!11!!!!!1 The RIGHT mutations. Those magical mystery mutations can change an invertebrate to a vertebrate just because change happens. Those mutations can change a fish into a land animal and then a land animal back into an aquatic one- again just because change happens. Eliminate the bad changes and the good get to accumulate and voila!
These magical mystery mutations operate when/ where no one can observe them. They cannot be studied which means no testing and no verification. And if you don’t accept that then you are an IDIOT with religious motivations. 🙄
Mung,
What pathetic level of detail did you have in mind?
So let me see if I have this straight: You can’t imagine how a convoluted, somewhat baggy tube of relatively rapidly reproducing cells could evolve a slightly larger pouch that confers an advantage vis a vis survival? That sounds more like a failure of imagination than a deficiency of the theory.
Different tests. The test that says I am related to my father would show neither of us are related to chimps.
The only way to test Common Descent is to account for the anatomical and physiological differences observed.
Voles- A lot of micro but no macro
Yup after all this “evolution” a vole is still a vole.
Oh, they didn’t get the “right” mutations, eh?
Mung,
I am satisfied that explanations that require only generational variation and sampling – things which happen – are preferred (by me) to explanations involving invisible and undetectable entities acting as if generational variation was all that was going on. It seems an unnecessary extra job for such entities already fully occupied with moral bookkeeping and such.
No. I’ve already stated that I think claims of common descent are testable.
dazz,
How do you know descent with modification did it? Are you claiming that de novo proteins and other structures can form with variation from reproduction? How do you show that your knowledge is not based on a-priori assumptions?
Mung,
Ah Jeez, another opinion piece where someone uses a word. That’s it, then. Can’t argue with that. This is BA77’s tactic!
Rumraket,
How many mutations do you think are required to build an appendix?
There isn’t anything about generational variation that can extrapolated into macroevolution. So that would be a problem
Rumraket,
Is it correct to conclude that the appendix is not a vestigial organ then Mikkel? Because if a vestigial organ is explained by the disappearance of the selective pressure to keep it / evolve it, then it seems to me positive selective pressure is the opposite to that
Frankie,
Word-gaming on Darwin’s choice of word: providing comfort to Creationists for 160 years and counting.
What is the alternative,somehow it was designed and caused 41 times?