I come from the Michael Behe school if ID. I accept common descent, by which I mean universal common ancestry. It seems to be the consensus view in science, it seems reasonable to me, and I don’t have any compelling reasons to doubt it.
But could I actually defend my belief in common ancestry if asked? All living organisms share certain features in common. Organisms leave offspring. Therefore, universal common ancestry. That sounds pretty weak, I admit. I need to do better.
I don’t believe that new organisms appear out of thin air, so to speak. I accept that the organisms of today are the offspring of prior organisms. Even young earth creationists accept common descent prior to the flood and common decent after the flood, though they resist the idea of universal common ancestry. I still haven’t figured out how and where they draw the lines though, so why should I draw a line that I cannot defend. Therefore common ancestry. That still sounds pretty weak, I admit. I still need to do better.
So time to hit the books. What are the arguments for universal common ancestry in the books on evolution that I have. Erm… Halp!
Why do folks believe in universal common ancestry and what is the best book on “the evidence for evolution” to refer to in order to find the best arguments in favor of universal common ancestry?
What if it’s not the evidence for the theory of common descent per se that leads people to accept it, but rather how the theory of common descent provides an explanatory framework. Does its explanatory power outweigh the need for evidence for it and do people confuse what it can explain with what constitutes evidence for the theory?
What is the evidence for universal common ancestry and why is it considered evidence for universal common ancestry?
Sure it has. that’s why I am asking. lol. Books keiths. Focus. Books written for the general public laying out the case for universal common ancestry. Do you know of any?
Sal:
From Sal, of all people. LMFAO.
How many times does it have to be explained that the observed mutation rate is after DNA repair has already happened? Genetic variation comes from mutation. Humans have low genetic diversity compared to most species, but how is that relevant anyway?
No, that’s choosing sequences that can be tested by the method he uses. Are you suggesting that he should have sampled inappropriate sequences too? Do you have any idea whatsoever what test Theobald performed? Of course the test didn’t explain orphan systems. It didn’t explain a lot of things, including the retrograde movements of the planets, why you should consider a Roth IRA, or why it took so long for the Cubs to win the World Series. It explained only those things the test was intended to explain. That’s what all tests do.
You have a hammer, but not all questions are nails. And in fact, that’s actually a banana in your hand, not a hammer.
So you DO have a sense of humor. It’s just defective.
It’s evidence, not proof. And he mentions other evidence in passing as introduction to his test. I don’t see why it should be treated as a reason not to read about or credit the test itself.
Particular books with particular sequences of words. Languages that have the Lord’s Prayer starting with “Our Father, which art in heaven…” etc. have common descent. You don’t agree?
keiths:
Mung:
Now you’re asking. Hence my incredulous question about the preceding 10+ years:
Mung:
Why are you asking for books when we’ve already referred you to an excellent online resource?
If you want to understand the scientific case for common descent, wouldn’t it make sense, even to a Mung, to read a highly-recommended essay whose subtitle is The Scientific Case for Common Descent?
I asked for books first. Then you referred me to an online resource.
If popular books on evolution, such as the one by Jerry Coyne, Why Evolution is True, don’t make the case for universal common ancestry, then that could be a reason why people have not learned why it’s the consensus view in science.
Perhaps universal common ancestry has nothing to do with why evolution is true.
You say that like it is a bad thing
All human knowledge is fallible and therefore uncertain. Explanations are judged against competing explanations, Newton was superseded by Einstein. As will Einstein likely be by something which explains observations better.
Look at the science of ID, there is not even consensus of what science is,much less a consistent belief of how ,what, when or who of design.
Mung:
So? As I asked:
What is it with IDers and their Theobald phobia? Even Mung, who accepts common descent, is scared to read Theobald (or perhaps afraid to admit that he doesn’t understand Theobald.)
If you’re having trouble with parts of Theobald’s essay, Mung, then just ask for help. If you display a genuine willingness to learn, people here will help you out.
Most of the arguments you named yourself already: All cells use ATP as energy currency, all use DNA and RNA for coding and expression of genetic information. The genetic code is, with minor variations, universal. And all domains use similar molecular machinery for transcription and translation of genetic information.
As for a book: I don’t know of one that covers universal common descent in any detail. Maybe you like Andrew Knoll’s “Life on a young planet”, which deals with early evolution of microbial life, not much on deep phylogeny though.
I actually got something right? What a lucky guesser I am!
That the things held universally in common by all known organisms would be evidence for their universal common ancestry. Who woulda thunk it. Eh keiths?
I’ll be sure to read Theobold to see if he names anything that I missed.
Creationism might explain that
Or maybe that explains creationism.
Some kind of inbreeding, anyhow.
Glen Davidson
Mung,
Of course they’re evidence for universal common ancestry. They’re also evidence for universal common design.
Get off your ass and read Theobald so that you’ll understand why the bright folks accept common descent and reject common design.
It’s not good evidence. Even with such a ridiculous standard of evidence, I still read it.
No. When the start is “Our Father, which art in heaven…” etc. then we are quite certainly dealing with one and the same language, not with different related ones.
lol
OK, you sure can cling to a metaphor. But now suppose you see the Wycliff translation, or some other translation with slightly different wording. Or suppose you see a translation into Frisian. Related languages? Leaving the metaphor, the point is that many features of organisms have detailed similarity that goes way beyond “they have vowels. Your analogy was a bad one.
You’ll need to explain what you mean by “common design.”
Erik,
This, lest we forget, from the man who thinks the commonality of Flood stories in diverse cultures is good evidence for their common descent from eye witness accounts of Ye Actualle Floode.
?
Which of course, doesn’t count as evidence that Erik is a Christian
You are not going to run away from the destiny of endosymbios in the origin of eukaryotes…neither will John Harshman…while still denying it …lol
Looks like god Theobald is just as confused as the rest of the Darwin’s faithful here…Or are they confused because they look up to him to save their faith???
So common descent is reasonable eh
First correction.
its not the scientific community. There is no community. it could only be those who studied/got paid the subject. its not all scientists. In fact since science is very subject driven it could only be small numbers that have become accomplished in the subject to justify a claim to being scientists in the subject.
Its not even all biologists. They do actual biology. Hands on goo. Its only evolutionary biologists or creationist biologists.
How much community is that? whats the head count.
YEC creationists do accept common descent, as said, and examples are people.
Behold the diversity in biology of people and yet we say from one couple only 6000 years ago.
Then we have the snake example. the snake was cursed with no legs and all snakes have no legs and so snakes were one kind and looked alike when created. behold the diversity today.
Just because biology can change a little is not evidence or hinting it could change a fish into a rhino.
On creation week everybody had eyeballs and lips etc. It would be this way from a common design from a creator. why not? what else?
why not the God of physics/laws do the same thing in biology.
surely looking at likeness in traits and only imagining the option of common descent is poor research and thinking.
so likeness in traits is not proof of common descent.
Yet common descent conclusions is eNTIRELY based on matching traits.
Body plan likeness is not intelligently proof of common descent.
Its just a line of reasoning from raw data.
Genetics etc etc are all the same concept. jUst matching things and saying AHA common descent!!
Its old poor research from the 1800’s.
people are getting smarter and common descent based on mere comparisonism is not good enough.
Indeed do evolutionists have evidence for common descent.
Mung:
keiths:
Mung:
Stop stalling. Read Theobald.
Byers:
Well, that settles it.
What are you talking about? Of course it is…Not only that, it is also communion, communism and camouflage as it all evolved from it…
They do… for common desert
Theobald basically says the same thing I said.
I left out the argument from handedness but got everything else.
Mung,
That’s the intro. There’s more.
Another thing about the common descent vs common design argument is that some of the dissimilarities don’t make sense if they are the result of common design.
An example would be why there are different DNA replication machineries, and different membrane lipids in bacteria vs archaea, as there doesn’t seem to be any good funtional reasons why these should be different. As far as I’m aware, there is no environment on Earth where archaea live, where there isn’t also bacteria living alongside them.
Another would be enhancer and promoter regions, why would those be different at all? If both bacteria and archaea were designed by the same designer, who re-uses parts for it’s designs, why even change the regulatory elements? To transcribe some protein coding gene in bacteria, which has a homologus gene in archaea, there’s a need for an upstream piece of DNA that can be recognized by a transcription factor and initiate transcription. Yet those two regions can be wildly different, while the gene can be quite similar and conserved? Why? Why not just re-use the exact same enhancers and promoters, and the same transcription factors? Why the difference between them? Again, you’ll find both organisms living next to each other, so there doesn’t appear to be any environmentally determined functional constraints that explains why the promoters should have a different sequence.
This is one of those cases where, if they really were exactly identical, that would make sense as a consequence of “common design”. You could then say a designer is using something that has already proven to work, for another project. Yet this is not what we see.
If all the things we see in the diversity of life which are similar, were not merely similar but identical, the branching pattern would disappear, and it would become extremely difficult to explain how they could have been conserved completely unchanged for billions of years. If that was the situation we were in, then common design would make more sense. Yet that is not what we see. Even the most ultra-conserved and universally-present elements in all of life (like some ribosomal RNA or proteins) still recapitulate a branching pattern that correlate with the branching patterns captured by other widely distributed elements. They show divergence when they wouldn’t need to beyond environmental adaptation.
Examples where functional constraint could explain differences for ribosomal protein and RNA, would be extreme thermoadaptation in hyperthemophilic archaea and bacteria as compared to their more “normal” counterparts. As in there are good physical reasons why a prokaryote that lives at 120 degrees C would need changed RNA and protein sequences, so they retain folding ability, stability and function at extreme temperatures and pressures. But again the problem crops up. There are both hyperthermophilic bacteria and archaea living alongside each other in extreme temperatures. Their ribosomal RNA and protein is thermoadapted and clearly different from their “normal” counterparts in more mundane evironments. But again they’re not identical. So again the branching patterns show up even when there are environmental factors that a designer could invoke to explain why we should find them to be identical.
There are a virtually endless amount of indicators like these that we are looking at the results of a very, very long process of descent from a common ancestor, through independent lineages.
Common design simply cannot rationally explain these observations. The kinds of rationalizations you have to invoke why we see these patterns on a design-model become complete illogical, and effectively unfalsifiable, as you are in the end forced to conclude that the designer has designed life either by accident or intentionally so that it looks like it evolved by common descent.
From my reading he picked 16 proteins. So he only looks at proteins and only a few proteins at that, and the reason they were picked was because they are ubiquitous.
Am I wrong?
No one but you knows what you mean when you say common design. You’ll have to define what you mean by common design.
Yes, sure. Common design is when the same (or a very similar) designer is designing the things we see, and so is basically re-using things from it’s designs in other things it is designing. This is supposed to explain why things in one thing (like the ribosome in bacteria), are similar to things in another thing (the ribosome in archaea).
This could be invoked, at least superficially, to explain why all life uses DNA-based genomes of an identical handedness, for example. Because the designer is just re-using the same things it has already designed.
A central pillar. So you would think that books trying to convince people of “the truth” of evolution would be sure to cover it. Right?
But this is where I argue that, if we really go with that sense of common design, it still turns out not to make sense. There are a few things we can sort of invoke common design to make sense of, but there are so many other discrepancies that, when we try to account for all of the data we have, it stops making sense. That common design as an explanation for similarities, doesn’t actually explain them, both because there are patterns in the similarities and dissimilarities, and there’d be no reason for them to be merely similar instead of outright identical, in many situations.
That if we really go with the common design rationalization, things shouldn’t actually be merely similar, they should be virtually identical down to the last atom. And the only deviations should be due to funtional necessity.
Could you move the discussion of common design to the common design thread vs common descent thread? This thread is about universal common ancestry.
Thank you.
This is a thinly disguised God of the Gaps argument.
We’d all like to answer the question of where this huge diversity of life came from. Right now there are mountains of evidence in diverse areas that mutually reinforce our understanding of evolution.
To answer this question for himself Sal focuses in on one minor area- orphan genes/features. Now within this area are plenty of beautiful examples of how non-coding sequences can give rise to proteins or how features can be modified incrementally for another function, but Sal ignores those and just focuses in with extraordinary tunnel vision on what ever fraction of these features we currently don’t have an explanation for.
Its always seemed to me that the major players in ID are completely uninterested in grappling with the evidence in totality.
Choices for design should be based on suitability to need, not to heredity (or at least to other choices that group together without grouping by fit of function to need–if one disputes the “heredity” aspect).
Of course there could be exceptions, such as to have a certain look. But that doesn’t explain why bird wings have a rigid structure fused out of bones that became articulated in terrestrial dinosaurs. It’s idiotic “design,” while evolutionary processes have to work with what is inherited.
Glen Davidson
I think most books that are written to convince people of the truth of evolution are more written for people why deny macroevolutionary change in general (fish becoming tetrapods, land mammals becoming whales, monkeys becoming humans), and that the authors suspect people don’t really care whether some bacterium shares and ancestor with an archeon three thousand eight hundred million years ago. I think they’re generally written for creationists or people who mostly deny that humans came from something other than humans and have an evolutionary history.
And one way to explain why some things are evidence for universal common ancestry is to contrast it with another possible explanation. It is relevant as it argues for common descent rather than independent emergence. The mere fact that I contrast it with common design doesn’t make it unfit for this thread.
And you asked me what I meant by common design, so I answered.
As Sal called it, junk science.
Yes Sal, your sampling bias is indeed junk science.
But evaluating relatedness depends upon dealing with related sequences, not upon unrelated (or uncertain, anyway) sequences. It’s using the relevant data, while not using what is not relevant (or whose relevance is unknown, at least). It’s not cherry-picking to use the relevant data, Sal just wants to use the “exceptions” as an excuse to throw out the relevant data.
Why wouldn’t he? He doesn’t even see why objective science should exist, since merely finding out what’s true (supposedly) doesn’t get you what you want. It’s a marvelous example of just how appalling is the effect that ID has upon minds.
Glen Davidson
I like undisguised Darwin of the gaps arguments better…especially when they are presented as facts…lol
I guess one way of describing it is that IDers always look to the facts of nature that don’t tell us anything so they can use their default explanation as opposed to the facts that do tell us something because those always point to evolution
Whats a Darwin of the Gaps argument?
Very witty Wilde, very VERY witty!
Do snakes literally eat dirt?
I just don’t want this thread to get derailed by Sal’s silly “common design” argument, especially when there is already a current thread on that specific topic.
🙂
If something doesn’t fit or even contradicts evolutionary prediction; Darwin of the gaps is used or you say it evolved or it is complex but it evolved somehow…
Just like in this study. The results don’t fit the evolutionary predictions:
Instead of saying something is wrong with gene regulations between humans and chimps, you have to use Darwin of the gaps instead; in this case complex instead of saying as it is an face the consequences of Darwinian bullies…
Gene regulation differences between humans, chimpanzees very complex
“The team found 815 genes with differing mRNA expression levels but only 571 genes that differed in protein expression. In total, they identified an estimated 266 genes with mRNA differences that did not lead to changes in protein levels. They found similar results in rhesus macaque cell lines when compared to both chimpanzees and humans, confirming the trend.
“Some of these patterns of mRNA regulation have previously been thought of as evidence of natural selection for important genes in humans, but this can no longer be assumed,” Gilad said.
The study raises questions over why mRNA expression levels differ between species if they do not necessarily cause protein differences. Although further study is needed, Gilad believes this study suggests that protein expression levels evolve under greater evolutionary constraint than mRNA levels, via a yet-uncharacterized compensation or buffering mechanism.
And there you go…by using a Darwin of the gaps argument you keep your job, possibly the funding, and the Darwinian bullies will leave you alone…
That’s how the systems works… and the ones that dare to dissent are punished and eliminated…