Universal Common Descent Dilemma

  1. Despite lack of observational basis, Darwin proposed Universal Common Descent (UCD) saying:Therefore I should infer from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed“. He also said elsewhere (referring to UCD): “…the littlest creature (or four or five of them)…” With his remarks, Darwin left the door open to creation (“life was first breathed”), but since then, Neo-Darwinists have rejected creation and replaced it with belief in undirected abiogenesis while maintaining belief in UCD.
  2. UCD is incompatible with the current view of Earth as just an ordinary planet circling an ordinary star located nowhere special inside an ordinary galaxy. If Earth is “nothing special” and abiogenesis is an ordinary “arising” of life from non-living matter, spontaneous abiogenesis would be a trivial common occurrence here on Earth as well as throughout the Universe, and we would have many “trees of life” instead of one. However, until now, all abiogenesis experiments have failed to produce life, spontaneous generation has been rejected, and the Fermi paradox stands, all these keeping the single “tree of life” and UCD hypothesis still alive and still inexplicable.
  3. Conditions for starting life should be similar to those required for sustaining it. The Big Bang model mandates a beginning of life. Furthermore, once started life must be sustained by the same or very similar environment. And since life is being sustained now on Earth, abiogenesis should be ongoing contrary to all observations to date. Tidal pools, deep sea hydrothermal vents, and the undersurface of ice caps have been hypothesized to originate abiogenesis due to their persistent energy gradients, but no abiogenesis or its intermediate phases have been observed around these sites. Given these, the only methodological naturalistic alternative is ‘limited window of opportunity for abiogenesis which suggests primordial life substantially different than all known forms of life, and perhaps originating on another planet followed by panspermia. However, this alternative defies Occam’s razor and the absence of supporting evidence including the earliest ever known fossils (stromatolites) that are of commonly occurring cyanobacteria rather than of alien origin.
  4. Universal Common Descent requires an inexplicable biologic singularity. All known forms of life are based on the same fundamental biochemical organization, so either abiogenesis happened only once or it happened freely for a while but then it stopped when the ‘window of opportunity’ closed and only one organism survived to become the Last Universal Common Ancestor (LUCA) of all existing life on Earth. However, these two biologic singularities should be unacceptable given the lack of evidence and the assumption of continuity in nature. Furthermore, the second scenario requires two discontinuities: one for the cessation of abiogenesis and the second one for the bottleneck leading to LUCA.
  5. In conclusion, UCD hypothesis leads to a number of bad and very bad scenarios: a) Earth is “nothing special” should lead to a “forest of life” rather than a single “tree of life” and to ubiquitous abiogenesis (unobserved); b) Alien life plus panspermia is refuted by the Fermi paradox and oldest known stromatolites fossils; c) Single event abiogenesis is an unsupported and therefore unacceptable singularity; d) ‘Window of opportunity’ abiogenesis followed by LUCA bottleneck is even less acceptable double-singularity. And this brings us back to Darwin’s “open door” to creation, perhaps the most rational alternative that fits all biologic observations.

Pro-Con Notes

Con: Maybe abiogenesis is happening a lot. I think the already existing life would dispose of it quickly though.

Pro:  if so, 1. We should be able to duplicate abiogenesis in the lab; 2. We should see at least some of the intermediate abiogenesis steps in nature; 3. Existing life can only process what looks like food. Cellulose is a well known organic material that cannot be broken down by a lot of organisms and is known to last as very long time in dry conditions.

1,101 thoughts on “Universal Common Descent Dilemma

  1. Allan Miller:
    If evolution were true, everything would be really clear-cut. Apparently.

    There is no recorded incidents of cats mating with bears interestingly enough.

  2. phoodoo: There is no recorded incidents of cats mating with bears interestingly enough.

    And you think this makes it easy to tell whether different organisms are biological, or ecological species, or subspecies, or what? How about a bacterial classification system, Ursids don’t mate with felids so you can tell E coli strains apart from Salmonella under confocal microscopy? Let’s not even get into plants. There are over 10.000 species of ferns alone, apparently.

  3. Entropy: 1. Lots of quite divergent forms can be “shaped” by breeders by selecting generation-after-generation for features of interest. Darwin used to breed pigeons, if I remember correctly. So pigeons were exemplified, with shapes I had never seen myself before reading the book. (This is why Darwin named the process he proposed “natural selection” as a simile to breeder’s selection.)

    2. It’s obvious that not every offspring lives to reproduction, since if they did, populations would grow beyond the resources of the planet very quickly. It’s therefore possible that there’s at least some competition for survival.

    3. Variation exists between individuals in a population of any species. Since the offspring tends to look like their parents (even if not perfectly), it makes sense that if some hereditary characteristics are behind survival to reproduction, then such characteristics will be passed on to the offspring. As the process goes on and on, the populations should consists of better adapted individuals.

    4. Is this so? Any evidence of diverging populations? Well, Darwin found that fossils that looked similar to current species in some geographical location were located within such geographic location. For example, giant sloth fossils in places where today’s sloths live.

    5. Is this so? Any evidence of diverging populations? Darwin noticed that the more similar two species, the closer they lived. Distance seemed to correspond with divergence in the looks of species in the same families. I don’t remember which examples he used.

    6. How far does this go? Any evidence that, say, something like eyes could evolve? Darwin showed that today’s life forms showed examples of eyes, from very simple to the complex eyes we’re used to think about exist, which show that eyes could evolve in “stages” “each useful to its bearer.”

    7. Etc.

    So, some populations diverge a bit, therefore they all diverged all the way.

    No explanation came from Rumraket. Yours has the fallacy he criticized. Okay, I guess.

  4. Erik:
    So, some populations diverge a bit, therefore they all diverged all the way.

    Some populations? Just a bit? I mentioned ranges in divergence Erik, not just tiny divergences. Also, I didn’t count how many Darwin presented. I just gave you a tiny bit just to get you started and understanding that it wasn’t just finches. You didn’t expect me to write a whole volume about evidence in a single comment, did you? You didn’t expect me to post the whole of On The Origin of Species and then all the research done ever since, did you? You might also have missed these other paragraphs (some bold to help you out, as if you cared):

    Entropy:
    So, as this small list, obviously not possibly making too much justice to that 600 pages book, shows that the 600 pages didn’t just say “finches! look at finches! therefore evolution!” I’d advice reading it, even if enormous amounts of evidence have accumulated ever since, and even though Darwin didn’t know much about how heredity works, and even though there’s more to evolution besides natural selection.

    For much more than that you can use google scholar to find the latest research about evolution in scientific journals, and, as Rum showed, there’s also online explanations that try and make it accessible to the more general public.

    Erik:
    No explanation came from Rumraket.

    Rum was wise enough not to bother explaining it here, when there’s more comprehensive explanations online available. easier to point to them than trying to summarize. After your dismissal of my explanation, I see Rum’s take on the matter. Of course you’d dismiss any explanations here, they’d necessarily be summaries of summaries, thus you’d jump to “meh, that’s just tiny and few.” Had you followed the link you’d find four long web pages instead. But, as I predicted, you don’t really care. So, I’m not too surprised.

    Erik:
    Yours has the fallacy he criticized. Okay, I guess.

    Your carelessness, or your illiteracy, might have blinded you to how I intended to help you out, but that’s what I expected. With you guys it’s never about evidence or explanations, with you it’s just your claims, that are then shown wrong, but then you don’t even try reading for comprehension. At least you could have acknowledged that now you knew it’s not just finches. That would have shown a tiny bit of maturity. Anyway, since you’ll be dismissing this too, I’ll leave you to your ignorance.

  5. Entropy: My prediction, you really don’t care because you already made your mind that only what creationist charlatans say about evolution counts.

    I resent being called a creationist!

  6. Erik: By what reasoning is the principle of evolution (of species by common descent) established then?

    By the principle of divergence.

  7. Mung:
    I resent being called a creationist!

    Sadly, your sense of humour flies over my head too often. Good one!

  8. phoodoo: There is no recorded incidents of cats mating with bears interestingly enough.

    Oh, sorry, I mean if evolution were true nothing would be clear cut. Apparently.

  9. Entropy,

    Erik really is a bit of a special case. If I recall correctly, he’s another who denies even simple speciation, larding ignorance with trademark haughtiness. So we’ve got Erik, phoodoo, Bill Cole, Nonlin, J-mac and Joe G in the TSZ No Speciation Roll of Honour.

  10. Allan Miller,

    Allan,
    Nothing to do with this OP. Sorry.

    I’m working on the piece that is related to your area of expertize: gender evolution. It mainly relates to a quarter of youths who seem to genderless, or gender nonconforming, and the evolution of gender in view of evolutionary theory, population genetics and reproduction.

    Can you point me to some papers that explain why natural selection evolved gender reproduction and why it is now devolving it in homo sapiens?
    I know that you had been very busy in the past to address this issue but since you don’t seem to be as busy now, maybe you can help me out…

    Thanks!

  11. Allan Miller:
    Entropy,

    Erik really is a bit of a special case. If I recall correctly, he’s another who denies even simple speciation, larding ignorance with trademark haughtiness. So we’ve got Erik, phoodoo, Bill Cole, Nonlin, J-mac and Joe G in the TSZ No Speciation Roll of Honour.

    That’s funny, since your side can’t even agree on what a species means.

    Why do you call different types of dogs, dog breeds, and not dog species, since they are all different, and many types can’t even breed well together?

    So here’s what we know: We can get vastly, vastly different looking animals through selective breeding. And plants too for that matter. And yet we never, ever cross this so called species barrier (Granted,we are keeping in mind your side has no definition of species-or a million definitions- same thing).

    We also know that bears still can mate with bears. And cats can’t mate with bears.

    If evolution were so dam obvious and easy, you would think that by supposedly speeding up the process through artificial selection, we could make all sorts of new species and prove evolution, right there in the lab. And yet we can’t, not even with simple bacteria. How many generations will it take?

    What should that tell you, skeptics? I know what it tells most skeptics-close your mind even harder. Funny lot you all are.

  12. phoodoo: And you we never, ever cross this so called species barrier (…)

    If evolution were so dam obvious and easy, you would think that by supposedly speeding up the process through artificial selection, we could make all sorts of new species and prove evolution, right there in the lab. And yet we can’t…

    We have. Evidence for rapid speciation following a founder event in the laboratory.

    How many generations will it take?

    It took approximately 20 years for the invertebrate worm Nereis acuminata to speciate through isolation from the wild-type species, by becoming incapable of producing living offspring when paired with the wild-type (the offspring weren’t just infertile hybrids, they died before reaching a juvenile stage) in a laboratory setting.

    Phoodoo why did you claim this hasn’t happened without bothering to check first?

  13. Rumraket,

    What do they call this new species they created in the lab?

    Well, You did your best at googling Rum. You found a paper from 1990, that shows some flatworms that give birth to not particularly healthy offspring. And furthermore states:

    “this was not a controlled experiment, consequently results from our study can not help to resolve the ongoing controversy”

    Wow, skeptic.

    Chihuahuas can’t mate with St. Bernards. New species?

    Ha. Skeptics!

  14. Rumraket: Phoodoo why did you claim this hasn’t happened without bothering to check first?

    Rum, why do you claim this has happened without bothering to check first?

    Oh wait, I know, you are skeptic!

  15. phoodoo: Keep googling Rum.

    Well we’re on the internet, so that’s the only way to actually find and present evidence in an internet discussion. What the hell else do you expect me to do if I am to back it up when I dispute your claims? You seem to say that googling for information is somehow a bad thing. I guess that explains why you are in the position you are. Stay ignorant deliberately if you so wish. To each his own I guess.

  16. phoodoo: Rum, why do you claim this has happened without bothering to check first?

    But that’s exactly what I did. I bothered to check, and I even bothered to check citing articles exactly because it was an old reference.

    It’s becoming increasingly clear that these are foreign concepts to you. Apparently even taboo. As if checking and correcting yourself is a bad thing to be embarrassed about. I feel I learn more and more about you. Is that really what it is like in your social circles?

  17. Rumraket,

    Rumraket: You seem to say that googling for information is somehow a bad thing.

    No, that’s your frequent criticism not mine. I was parodying you.

    The question is one wonders what you think you have found? You think finding two strains of lopseed plants that can’t cross pollinate will help you solve the conundrum of bears being bears and cats being cats, and all the dog breeding in the world has only ever given us more dogs?

    You know what the two strains still are? Flowers. Maybe you can try going reading about the difficulties in separating this one small group of plants.? Why is it difficult. Because they are just like dog breeds-totally different animals and yet all dogs in the end.

    https://en.wikipedia.org/wiki/Phrymaceae

  18. Phoodoo: do you think that divergence happens?

    1) If so, what precludes divergence from causing genetic reproductive isolation, in addition to fiddling with form and habit?

    2) If not, do you think even subspecies waddled off that overloaded ark?

  19. Rumraket,

    Intellectual honesty? What in hell do you think you are playing at? The Darwinati will hear of this. Expect an ‘educational’ visit.

  20. Allan Miller:
    Rumraket,

    Intellectual honesty? What in hell do you think you are playing at? The Darwinati will hear of this. Expect an ‘educational’ visit.

    Don’t forget the authors of that paper. How dare they challenge the almighty Darwinist dogma and the Holy Materialistic Establishment?

    OK Allan, you take care of Rum, I’ll go get that Francisco J. Ayala guy. Untolerable!

  21. phoodoo:
    We also know that bears still can mate with bears. And cats can’t mate with bears.

    That looks like the Biological Species Concept: species defined on the basis of interfertility.

    phoodoo: If evolution were so dam obvious and easy, you would think that by supposedly speeding up the process through artificial selection, we could make all sorts of new species and prove evolution, right there in the lab. And yet we can’t, not even with simple bacteria.

    Bacteria? NOT the Biological Species Concept then.

    phoodoo: You know what the two strains still are? Flowers. Maybe you can try going reading about the difficulties in separating this one small group of plants.? Why is it difficult. Because they are just like dog breeds-totally different animals and yet all dogs in the end.

    And that is not the Biological Species Concept either but rather the they-all-look-like-flowers-to-me concept.

    phoodoo. I think it is only fair that you explicitely state your personal species definition (only one, I believe?), since you have broadcast contradictory messages about what you consider to be different species. Otherwise we will just be chasing the ever moving goal posts.

  22. Corneel,

    The BSC seems implicitly the one generally gone for, when pushed. Erik, Bill and phoodoo have all declared interbreeding as indicative of genetic relationship. Which is interesting. Of all the various mechanisms of pre- and post-zygotic isolation, the key one is F1 fertility, for gene flow. If that fails, the rest is academic. This requires a successful meiosis between the parental genomes, which requires extensive sequence alignment.

    So, ironically, in a roundabout way they favour substantial alignment as a diagnostic test of common descent when nature does it, but not when we do.

  23. Allan Miller: So, ironically, in a roundabout way they favour substantial alignment as a diagnostic test of common descent when nature does it, but not when we do.

    Heh!

    Only valid for animals, I presume. It seems that no amount of genetic dissimilarity can split a group from the unified “boring ol’ flowers” clade.

  24. phoodoo:No, that’s your frequent criticism not mine. I was parodying you.

    No I’m pretty sure the opposite is true. I’ve said many times that the information is out there for people who want to learn, but they just have to be willing to learn and spend some time reading.

    The question is one wonders what you think you have found?

    An observed instance of speciation, which you claimed did not exist. Let’s just note for a moment that you were wrong when you claimed speciation had not been observed.

    You think finding two strains of lopseed plants that can’t cross pollinate will help you solve the conundrum of bears being bears and cats being cats

    That question is nonsensical. I don’t consider “bears being bears” and “cats being cats” a “conondrum” in need of solving.

    By the way, while on the topic of this ridiculous “they’re still bears/cats/dogs/flower/bacteria” thing – how many different cats have you tried breeding, or bears for that matter? Can panda bears mate with polar bears, or with grizzly bears and produce fertile offspring?

    So far you seem to only be aware that Grizzly and Polar bears can mate and produce fertile offspring. But how many different bears are there, can they all mate and produce fertile offspring?

    How many of the felines can do that? Can a house cat mate with a lion and produce fertile offspring, can a puma mate with a leopard and produce fertile offspring?

    and all the dog breeding in the world has only ever given us more dogs?

    What the hell else should it give us? Going by how you think two different species of plants are “still flowers”, you could just as well decide to call two species of canines that can’t interbreed “still dogs”.

    It seems you are now flying away with the goalposts on an intercontinental ballistic missile.

    You know what the two strains still are? Flowers.

    I knew this was coming. “They’re still flowers”. Hahahaha, oh my.
    This one is almost as stupid as “they’re still bacteria”, which constitute an entire domain on the tree of life. There are hundreds of thousands of species of flowers, and bacteria for that matter.

    When humans and chimpanzees split from their common ancestor, they remained apes. “They’re still just apes”. Did you know you’re “still a mammal?” That’s essentially your response.

    Oh gee, a flower species evolved and produced another flower species.You know trees also grow flowers, right? So by your fatuous new goalposts, even if something like a dandelion (a flowering plant) were to evolve into an cherry tree, the fact that it still flowers means, in your terms, it is “still a flower”. How fantastically stupid.

    Maybe you can try going reading about the difficulties in separating this one small group of plants? Why is it difficult. Because they are just like dog breeds-totally different animals and yet all dogs in the end.

    Completely irrelevant. There is now two species where before there was only one. Your challenge was met. You were wrong. Just own up to it and move on.

  25. Allan Miller: Intellectual honesty? What in hell do you think you are playing at? The Darwinati will hear of this. Expect an ‘educational’ visit.

    SHHH NNO, noooo.

    I’m sure I will be called before Arch-evolutionist Dawkins to confess and repent. If I am lucky.

  26. Rumraket: Bad example then.

    Good example of self-correction though!

    However, I don’t understand the point in arguing over whether or not speciation actually happens. I don’t see the point in coming up with examples. Though I could be wrong. someone might actually be convinced by it.

  27. Corneel: And that is not the Biological Species Concept either but rather the they-all-look-like-flowers-to-me concept.

    Everything is coming up roses!

  28. I think that everything that swims in the ocean must be the same species, from plankton to whales. It is the “ocean dwellers” kind. What’s the technical name, anyone?

  29. Mung:
    I think that everything that swims in the ocean must be the same species, from plankton to whales. It is the “ocean dwellers” kind. What’s the technical name, anyone?

    I think as long as we are playing evolutionist games, every animal alive is a new species. Why not? What’s a definition to an evolutionist? As long as they are different.

    Still not sure why evolutionists don’t count every kind of dog as a different species.

  30. phoodoo: I think as long as we are playing evolutionist games, every animal alive is a new species.

    This is not as ridiculous as the writer intends. Where sex is not involved, in the prokaryotes, one could argue that each individual forms a mini-clade with its own offspring.

    Where sex is involved, one only has to grab the idea of a population, where genes are mixed and shared, to get an idea of a species. Speciation can occur and populations drift into differences simply due to distance or other differences in a habitat.

  31. Mung: They are incipient species.

    How long have dog breeders been at work? It seems dogs domesticated themselves to some extent in prehistory. What breeders have done is choose dogs with desired attributes to breed from. This has the unfortunate side effect of reducing genetic diversity. The rate at which new alleles turn up is unaffected by selection, so rapid artificial selection in relatively small populations will exhaust diversity eventually.

  32. As a thought experiment, a simple way to create two species of dog on the BSC would be to kill*** all breeds except Great Danes and Chihuahuas. ‘They’re still dogs…’, croaks a confused onlooker.

    *** Sorry, what was I thinking, I meant ‘send to a farm’ …

  33. phoodoo: I think as long as we are playing evolutionist games, every animal alive is a new species.Why not?What’s a definition to an evolutionist?As long as they are different.

    Still waiting for you to enlighten us as to the One True Species Concept, then. You have the floor.

  34. ‘They’re still dogs…’, croaks a confused onlooker.

    Just look at the power of artificial extinction!

  35. Mung: However, I don’t understand the point in arguing over whether or not speciation actually happens. I don’t see the point in coming up with examples. Though I could be wrong. someone might actually be convinced by it.

    Presumably he asks for observations of speciation because to him that is actually an important type of evidence, otherwise one wonders why he even asks.
    But I agree with you in the sense that I don’t think the case for common descent, or evolution, rests on our ability to cause or to have observed speciation take place. And I could have told phoodoo as much, but I would have anticipated him taking such a response as a kind of “excuse” or rationalization to use when we “lack evidence” or something to that effect.

    That’s how creationists have responded in the past and for some reason phoodoo is fond of parroting what looks curiously like classic creationistic talking points. Maybe he’s just trolling, who knows?

    I think the evidence for common descent, which we have discussed here many times before, is what really settles this matter. But I didn’t want to go over all that again with phoodoo as I really don’t think he’s here to have an open minded discussion about that. So I thought it simpler to just produce a counterexample to his claim for the 1½ minutes of entertainment his goalpost tossing “they’re still flowers” would provide.

  36. Kantian Naturalist: Good to see you’ve come to a reasoned conclusion from your years of close study of far-from-equilibrium thermodynamics in open systems and molecular biology.

    I asked for ‘counterexamples’. But it’s clear you have none.

  37. Joe Felsenstein: Somebody tell nonlin.org about allopatry.

    Allopatry nonsense. Minor and reversible variability within the SAME family (what is a species anyway?) has not been shown to lead to “divergence of character” nonsense.

  38. Joe Felsenstein: Also the proof that evolution cannot happen because of the Second Law of Thermodynamics is (a) totally wrong, and (b) has failed so badly that Answers in Genesis outrightly recommends that creationists not use that argument. If nonlin.org thinks that the SLOT argument is valid, nonlin.org should start by reading the posts here refuting that. They’re easy to find. And any arguing about that should be a separate thread.

    We’ll see about that. I have some ideas but not entirely crystallized.

    This is from answersingenesis.org and is NOT supporting your claim:
    “The problem for creationists is that we have yet to generate a rigorously formulated entropy-based hypothesis that clearly shows that life cannot arise through natural undirected processes. However, evolutionists generally have failed to produce a reasonable argument which agrees with observation that the second law of thermodynamics does not prohibit evolution.”

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