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 Replies to “Universal Common Descent Dilemma”

  1. Allan Miller
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    says:

    Nonlin.org: Zero reading comprehension. That’s was the Darwinist claim that turned out false.

    It was never claimed that antibiotic resistant bugs would kill us all.

  2. Allan Miller
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    phoodoo: There are tall people and there are short people.Therefore speciation happens.

    Nah. Tall and short people can demonstrably interbreed. The Phoodoo Method in action: invent a situation in which a statement does not hold, and hope, by reductio ad absurdum, to deny the case where it does.

  3. Allan Miller
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    says:

    I’m noting a pattern with nonlin’s latest flurry of drive-bys: despite the crystal clarity of his prose, and the incisiveness of his insights into this sham discipline, all interlocutors suffer from comprehension issues.

  4. phoodoo
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    says:

    Allan Miller: Nah. Tall and short people can demonstrably interbreed. The Phoodoo Method in action: invent a situation in which a statement does not hold, and hope, by reductio ad absurdum, to deny the case where it does.

    Can Yao Ming breed with a midget? Are you sure?

    What if they simply choose not to mate, because of cultural differences, doesn’t that make them separate species?

  5. Entropy Entropy
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    Mung:
    I absolutely do not believe that the video which Rumraket linked to began with a single bacterium.

    Why? Why would this be such a spectacular problem? How do you think scientists can work on a single strain of bacteria if they didn’t isolate it first?

    Mung:
    But I’ll take this as an opportunity for me to learn something I did not know before.

    This sounds good. Let’s give it a try.

    Mung:
    How did they isolate one single bacterium?

    Well, I use to be in charge of a microbial collection, so I had to isolate colonies grown from a single cell all the time. There’s two main ways to do this that can be done in any microbiology lab.

    One of them is the dilution method. The method also works for counting the number of bacteria in a culture. It’s very simple: the scientists dilute a sample several fold using a sterilized solution, and spread a bit of the solution on a petri dish with growth media. Each dilution is 1/10 of the other. So, a single series of petri dishes could have 1/10, 1/100, 1/1000, 1/10,000, 1/100,000 etc. Of course, if the sample is highly concentrated, the dilutions have to go much further. At some point you see the growth of isolated single colonies, most of which would come, each, from a single cell. This can be repeated to ensure that the colonies come from a single cell.

    The other method uses a single petri dish. It’s called the streaking method. This one is a bit harder to explain. You start by putting a bacteriology loop into a flame to sterilize. Then you’d take a bit of a sample from some bacterial growth. Zig-zag streak it into a plate. Burn the loop again, pass it through a line of the prior streak to pull a few cells out and streak them into a new zig-zag. Repeat. This dilutes the bacteria at each streak, and you get isolated colonies, again mostly coming, each, from a single cell.

  6. Rumraket Rumraket
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    Entropy:
    The other method uses a single petri dish. It’s called the streaking method. This one is a bit harder to explain. You start by putting a bacteriology loop into a flame to sterilize. Then you’d take a bit of a sample from some bacterial growth. Zig-zag streak it into a plate. Burn the loop again, pass it through a line of the prior streak to pull a few cells out and streak them into a new zig-zag. Repeat. This dilutes the bacteria at each streak, and you get isolated colonies, again mostly coming, each, from a single cell.

    Yes. As you drag the loop through the streaks in this zigzag motion repeatedly, fewer and fewer bacterial will remain on the loop, until eventually only single ones remain here and there that will seed colonies. These can then be picked for an experiment.

  7. Mung Mung
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    Rumraket: In any case, it is actually not hard to isolate single bacteria with some common microbiology techniques.

    Thanks!

    Entropy: Well, I use to be in charge of a microbial collection, so I had to isolate colonies grown from a single cell all the time.

    And thank you too!

  8. Mung Mung
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    says:

    Allan Miller: I’m noting a pattern with nonlin’s latest flurry of drive-bys: despite the crystal clarity of his prose, and the incisiveness of his insights into this sham discipline, all interlocutors suffer from comprehension issues.

    Huh?

  9. Entropy Entropy
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    Mung,

    Not a problem.

  10. Allan Miller
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    phoodoo: Can Yao Ming breed with a midget?Are you sure?

    What if they simply choose not to mate, because of cultural differences, doesn’t that make them separate species?

    No.

  11. Mung Mung
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    phoodoo: What if they simply choose not to mate, because of cultural differences, doesn’t that make them separate species?

    Under which species definition would they be considered separate species?

  12. phoodoo
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    Mung: Under which species definition would they be considered separate species?

    Right again!

    Now you are starting to get it! Pick one.

  13. Alan Fox Alan Fox
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    phoodoo: What if they simply choose not to mate, because of cultural differences, doesn’t that make them separate species?

    Talk about groups or populations, rather than individuals. Start with a group where individuals are mixing and breeding. Any novel gene that is positively selected, will spread though that population. But separate the single population somehow – just distance, say, or a geological event causing a barrier (sea or mountains,) and those populations will no longer share novel genes. This is bound eventually to lead to speciation where the populations remain separate.

  14. phoodoo
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    Alan Fox: But separate the single population somehow – just distance,

    Or choice…

  15. Alan Fox Alan Fox
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    phoodoo,

    If you like. Both sexual selection and artificial selection involve choice; either by potential mates or by breeders.

  16. phoodoo
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    Alan Fox:
    phoodoo,

    If you like. Both sexual selection and artificial selection involve choice; either by potential mates or by breeders.

    Great, so when we play the game this way, when two organisms choose not to mate, they become different species.

    That’s what’s so great about evolution, there are no rules.

    So if someone asks if you believe that speciation happens, you might as well just say, “If you want…”

    Right Mung?

  17. Alan Fox Alan Fox
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    phoodoo: Great, so when we play the game this way, when two organisms choose not to mate, they become different species.

    Populations are species, not individuals.

  18. phoodoo
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    Alan Fox: Populations are species, not individuals.

    You play your rules, I’ll play mine. Allan will play his.

  19. Allan Miller
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    phoodoo: You play your rules, I’ll play mine.Allan will play his.

    You can play what you like, but strawmanning the theory you seek to critique makes you look ridiculous, rather than the theory.

    What’s ‘the problem’, by the way? The one involving Great Danes and Chihuahuas? You never said.

  20. Mung Mung
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    phoodoo: Right Mung?

    No, that is not right. Once you pick a species definition we can discuss whether or not speciation has taken place given that definition. But you avoid picking one. Go figure.

  21. phoodoo
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    Mung: No, that is not right. Once you pick a species definition we can discuss whether or not speciation has taken place given that definition. But you avoid picking one. Go figure.

    I choose all everything. Everything that exist is a species. Once something else exists, it becomes a new species. So I guess speciation takes place.

    No, no wait, I changed my mind. All possible things are a species. So in that case no speciation takes place, because you can’t make more than everything, you can only make less.

    So no, speciation is impossible. I just defeated Darwinism.

  22. Rumraket Rumraket
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    Are you okay phoodoo?

  23. Allan Miller
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    Evolution lies in tatters. How could it survive such an intellectual onslaught?

  24. Mung Mung
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    It doesn’t mean you have to leave TSZ though Allan. But perhaps now you are qualified to create your own OPs.

  25. Allan Miller
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    Mung:
    It doesn’t mean you have to leave TSZ though Allan. But perhaps now you are qualified to create your own OPs.

    I was going to resurrect my argument on sex at some point. But I haven’t the time for much more than sneering and chortling at the mo.

  26. phoodoo
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    says:

    Allan Miller: But I haven’t the time for much more than sneering and chortling at the mo.

    You have come to the right place.

  27. Mung Mung
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    lmao

  28. Allan Miller
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    phoodoo: You have come to the right place.

    Indeed …

  29. Nonlin.org
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    Rumraket:
    Nonlin: If YOU isolate populations it’s called breeding.
    1. No, breeding is when you pair up particular individuals to have offspring. As in bring them together to encourage pairing. Isolation is when you separate them to prevent them from breeding.
    Nonlin We tried for thousands of years and it does not lead to “new species”.
    2. Now you are confusing divergence in character, which was the specific claim of yours I was responding to, with speciation.
    You claimed we don’t see divergence in character. And we clearly do. The longer two populations remain isolated from each other, the more they will diverge in genetic and physiological characters. That’s true even if they technically remain the same species because they are capable of exchanging genes reproductively if brought back together.
    3. Are polar bears and grizzly bears not divergent in character? I say they are as they are clearly distinct in their behaviors and appearance. Despite the fact that they can interbreed and produce fertile hybrids.
    4. If your original claim was not about divergence of characters, but about speciation through reproductive isolation, you should have said that instead. But I think in fact your original claim WAS about divergence in character, and you’re now just trying to make it about speciation instead because you now realize how obviously stupid and false your claim was.
    Nonlin: No one isolates in nature.
    5. I agree completely. No one isolates in nature. Yet isolation does still happen in nature. Why? Because in nature isolation is due to various genetic, geological, and meteorological phenomena when isolation happens. Continental landmasses drift apart with oceans forming between them, mountain ranges form where they collide, upon which snow collects, which melts and create rivers, which splits environments up. Rivers run into the ocean and create large flood deltas. Oceanic islands come and go over geological time scales and so on and so forth. And then there are the genetic factors that create isolation through mutual infertility, such as the chromosome doubling that some times cause reproductive isolation in plants.
    Nonlin: There is no law saying “mutations must accumulate”.
    6. I agree there is no such law, they nevertheless do. It is simply just an observed fact that mutations happen and accumulate over time.
    Nonlin: In fact we see mutations reverse to baseline over time, not accumulate.
    7. No, we don’t. While reversals are of course possible, and do occasionally occur, they are very rare compared to the general onslaught of new mutations. For quite obvious probabilistic reasons.

    1. If YOU do it with your own pets it’s breeding. Get it now?
    2. One was supposed to lead to the other (whatever “speciation” even means). Variation is not necessarily “divergence”. You don’t actually know “the longer populations remain isolated”. What you DO KNOW is reversible adaptations. This includes epigenetic inheritance, the peppered moth color, the Darwin’s finches’ beaks, and antibiotic resistance that goes away when antibiotic use decreases.
    3. If “divergence of character” were true, you would expect to see a gradual transition from polar to grizzly. We don’t.
    4. Claim is clear: variation – yes; “divergence of character” – no.
    5. There’s very few of those mega-events. Insufficient to account for biologic diversity. Nothing ever separated humans from chimps. Physical separation theory fails
    6. I gave examples (see 2.) Where are yours?
    7. See 6.

  30. Nonlin.org
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    Rumraket: No it’s a demonstrable fact that that is how antibiotic resistance evolves. You can watch this excellent video for a demonstration.

    I did watch. That’s not “evolution”. It’s what bacteria do. Best confirmation is that ab-resistance goes away and that they do not transmutate into other bacteria.

  31. Nonlin.org
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    Allan Miller: But if reproductive isolation – biological isolation, not merely a stretch of ocean or a mountain – is trivial, you have your answer as to why there is not some kind of universal ‘meta species’ in a genetic continuum.

    Again, what do you do with humans and chimps that were never isolated by ocean or mountain?

  32. Nonlin.org
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    says:

    Allan Miller: There’s bound to be something in there about how much more deadly antibiotic resistant bugs are than their ancestors were in a world without antibiotics.

    You’re confused by a few extreme hospital cases. They tell us to not abuse antibiotics because…? What would be the point if bacteria had evolved?

  33. Nonlin.org
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    says:

    Allan Miller: It was never claimed that antibiotic resistant bugs would kill us all.

    Yep. “Survival of the fittest” and other such nonsense. One of many, random picked:
    https://www.wallstreetdaily.com/2016/10/19/superbugs-antibiotic-resistant-bacteria/

  34. Nonlin.org
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    says:

    Allan Miller: I’m noting a pattern with nonlin’s latest flurry of drive-bys: despite the crystal clarity of his prose, and the incisiveness of his insights into this sham discipline, all interlocutors suffer from comprehension issues.

    Nah, just those preprogrammed with the Darwinist religion. De-programming you is not the purpose. Distilling some half-decent, thoughtful counterarguments is. …an almost impossible task.

  35. Nonlin.org
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    says:

    Alan Fox: But separate the single population somehow – just distance, say, or a geological event causing a barrier (sea or mountains,) and those populations will no longer share novel genes.

    Where does everyone get impenetrable seas and mountains on demand? Can I have some mountains and tropical seas with islands?

  36. phoodoo
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    says:

    Alan Fox: But separate the single population somehow – just distance, say, or a geological event causing a barrier (sea or mountains,) and those populations will no longer share novel genes.

    Every new gene is a novel gene, that others don’t share until they do. What does it matter if they are separated or not? If its a “new” gene its new to everyone except for the “lucky accident” one.

    If you have a dog breeding farm, your dogs keep reproducing with only dogs in your farm. It never seems to stop them from reproducing with other dogs if you let them.

  37. Rumraket Rumraket
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    Nonlin.org: Rumraket: No it’s a demonstrable fact that that is how antibiotic resistance evolves. You can watch this excellent video for a demonstration.

    I did watch. That’s not “evolution”. It’s what bacteria do. Best confirmation is that ab-resistance goes away and that they do not transmutate into other bacteria.

    You watched but didn’t understand. It is evolution. Evolution is what bacteria do. Yes the antibiotic resistance would go away if the bacteria are allowed to evolve for a sufficient period of time in an environment without any antibiotic in it, because then there’d be no selective pressure to maintain the function of the adaptation to antibiotic, so loss of function mutations will eventually rid the bacteria of their gained resistance. Guess what, that is ALSO evolution.

  38. Rumraket Rumraket
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    says:

    phoodoo: Every new gene is a novel gene, that others don’t share until they do. What does it matter if they are separated or not? If its a “new” gene its new to everyone except for the “lucky accident” one.

    If you have a dog breeding farm, your dogs keep reproducing with only dogs in your farm. It never seems to stop them from reproducing with other dogs if you let them.

    The point of separation is to prevent gene-flow between populations. That is what leads to divergence. If you separate the two populations, the mutations that happen in population A, are unlikely to also happen exactly in the same way in population B. So over time, more and more mutations accumulate in A, and in B. But they’re mostly different mutations. So genetically population A and B become more and more different from each other.

    But if they’re not isolated, the members of A can go and breed with B, which means the mutations that happen in population A, now can find their way into population B when they have sex. The offspring of an A and B individual will have a mix of A and B mutations. That offspring with genes from A can then have sex again with more members from B, and pass those genes on to more B members. And the other way around, members from B can go into population A and so the B mutations can make their way into the A population. And so on and so forth until both populations have the same mix of genes.

  39. Rumraket Rumraket
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    says:

    Nonlin.org: 1. If YOU do it with your own pets it’s breeding. Get it now?
    2. One was supposed to lead to the other (whatever “speciation” even means). Variation is not necessarily “divergence”. You don’t actually know “the longer populations remain isolated”. What you DO KNOW is reversible adaptations. This includes epigenetic inheritance, the peppered moth color, the Darwin’s finches’ beaks, and antibiotic resistance that goes away when antibiotic use decreases.
    3. If “divergence of character” were true, you would expect to see a gradual transition from polar to grizzly. We don’t.
    4. Claim is clear: variation – yes; “divergence of character” – no.
    5. There’s very few of those mega-events. Insufficient to account for biologic diversity. Nothing ever separated humans from chimps. Physical separation theory fails
    6. I gave examples (see 2.) Where are yours?
    7. See 6.

    Honestly, I think your responses here are so bad that merely reading the post to which you are responding is enough.

  40. Allan Miller
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    Nonlin.org: Again, what do you do with humans and chimps that were never isolated by ocean or mountain?

    Those are not the only isolating mechanisms; they were merely examples. Another potential mechanism simply involves local extinction. Ranges demonstrably ebb and flow; populations blow across the land like smoke. Would you have it that it is impossible that there could ever be a ‘fire-break’ dividing a population, across which gene flow would be limited or nonexistent? Most especially in the case of the Creationist’s favourite animal, the chimp, and some hairless variant or other?

    Strong word, impossible. Populations are never divided. Not by anything. Also sprach Nonlin.

  41. Allan Miller
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    Nonlin.org: Nah, just those preprogrammed with the Darwinist religion. De-programming you is not the purpose. Distilling some half-decent, thoughtful counterarguments is. …an almost impossible task.

    Sure it is.

    Not only are your interlocutors incapable of comprehension, they are religiously indoctrinated to avoid the obvious conclusion that there should be a single global pan-species if evolution were true, by their feebly clinging to the notion that genes travel between subpopulations only by available paths, and at somewhat less than the speed of light.

  42. Allan Miller
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    phoodoo:

    If you have a dog breeding farm, your dogs keep reproducing with only dogs in your farm.It never seems to stop them from reproducing with other dogs if you let them.

    Unless all breeds other than Great Danes and Chihuahuas had been eliminated. Genes can presently only flow between them via other, serially more compatible, organisms. Divergence is already well in train; it just requires a quick snip to finish the job.

    This is of course an extreme supposition, but has a perfectly reasonable natural analogue: local extinction. Genes can only flow if there are organisms through which to flow. Stem that flow, and divergence can proceed unchecked by cross-fertilisation. Further divergence is itself a brake upon gene flow: it is self-reinforcing.

  43. Nonlin.org
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    Rumraket: es the antibiotic resistance would go away if the bacteria are allowed to evolve for a sufficient period of time in an environment without any antibiotic in it, because then there’d be no selective pressure to maintain the function of the adaptation to antibiotic, so loss of function mutations will eventually rid the bacteria of their gained resistance. Guess what, that is ALSO evolution.

    Who needs “selective pressure to maintain the function” when you have “beneficial mutations”? But obviously, reverting function means no “divergence of character” (because you can’t have it BOTH ways) and of course no evolution. And observe that the original eColi never became anything else, ab-resistance or not.

  44. Nonlin.org
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    Allan Miller: Those are not the only isolating mechanisms; they were merely examples. Another potential mechanism simply involves local extinction. Ranges demonstrably ebb and flow; populations blow across the land like smoke. Would you have it that it is impossible that there could ever be a ‘fire-break’ dividing a population, across which gene flow would be limited or nonexistent?

    So it could be this, it could be that, but it was neither. And what about chimps and bonobos that are NOT that different and would happily mate after 3 mil yrs? Don’t you see “divergence of character” makes no sense?

  45. phoodoo
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    Allan Miller: Unless all breeds other than Great Danes and Chihuahuas had been eliminated. Genes can presently only flow between them via other, serially more compatible, organisms. Divergence is already well in train; it just requires a quick snip to finish the job.

    This is of course an extreme supposition, but has a perfectly reasonable natural analogue: local extinction. Genes can only flow if there are organisms through which to flow. Stem that flow, and divergence can proceed unchecked by cross-fertilisation. Further divergence is itself a brake upon gene flow: it is self-reinforcing.

    But Allan, this completely misses the essential claim that evolution makes. The claim is NOT that sometimes some groups of animals stop mating. The claim is that NEW things emerge which outcompete or out-populate the old things, and thus novelty is created. But your examples are demonstrating the exact opposite of that. You are demonstrating how things are eradicated, not built new.

    If chihuahuas and great danes stopped breeding, where does that lead us to something new? It doesn’t.

    But the premise you have unwittingly slipped in, is that THIS is what you mean by speciation in nature. By diversification. If there are many different kinds of dogs, this shows evolution. If there are many kinds of finches, this shows evolution. And if you call wolves and dogs different species, this shows even more that evolution happens. And if some robins have a slightly redder chest, and some more brownish, even more evidence for evolution. And if some people are tall, and some are short, well that is clearly evidence of evolution in action!

    And so if one day we go and dig up bones of a chihuahua, and a great dane, but we don’t know what they are, well, there you go, transitional animals, from chihuahuas to great danes, look at the evolution which took place. Obviously over millions of years of course.

  46. Allan Miller
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    Nonlin.org: So it could be this, it could be that, but it was neither.

    Do you deny these mechanisms in toto? The fact that we may not know in a particular case does does not force the conclusion that none of them was involved, and some magic bloke done it.

    And what about chimps and bonobos that are NOT that different and would happily mate after 3 mil yrs?

    What about them? Clearly they don’t mate often enough to homogenise into a single type, as one can see from genetic analysis of patterns of introgression. It is bound to be the case, given the graduality of divergence, that there will be instances where it is incomplete. The existence of interfertile cases can hardly be evidence that the process can never run to completion, since they must exist at some point if it ever does.

    Don’t you see “divergence of character” makes no sense?

    I’m not sure I’ve ever used the term ‘divergence of character’. The divergence is in the genomes. To some extent these determine character, and so that changes too, giving rise to numerous potential pre- and post-zygotic isolating mechanisms, but the crucial checkpoint is F1 meiosis, which is substantially contingent upon the alignment of the DNA itself, rather than anything it specifies. The more differences between the the haploid genomes, the less likely a successful meiosis will occur, hence there is a progressive increase in hybrid sterility, even where matings do occur.

  47. Allan Miller
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    phoodoo,

    I know, you would dearly love to change the subject. Nonetheless, speciation is the process of divergence leading to the development of biological isolating mechanisms, and hence the cessation of interbreeding between them even on range re-merger. You’d rather talk about phylogenesis than cladogenesis, I get that, but as far as common descent is concerned, cladogenesis is the thing.

    The mechanisms I have outlined are collectively the reason why you can have two populations that cannot interbreed, and yet which have substantial DNA sequence alignment. Because of divergence and isolation, extensive sequence alignment despite hybrid mortality or sterility points to common ancestry of the two groups, just as, less controversially, it points to their common ancestry when two groups can interbreed.

    This too is a ‘claim of evolution’. Do you accept it? A simple yes or no will suffice.

  48. phoodoo
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    Allan Miller: nd yet which have substantial DNA sequence alignment.

    So your claim is, if two organisms have similar (it doesn’t really matter how similar does it) DNA sequence alignments, and can not interbreed that is evidence of common ancestry. Likewise if they have similar sequence alignment and can inter-breed that is ALSO evidence of common ancestry.

    So the only thing that would be evidence of NOT common ancestry would be if one organism uses DNA copying and one uses a xerox machine. And even then, they still could have common ancestry, but branched so long ago, that it is hard to trace that common ancestor.

  49. Allan Miller
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    phoodoo: So your claim is, if two organisms have similar (it doesn’t really matter how similar does it) DNA sequence alignments, and can not interbreed that is evidence of common ancestry.Likewise if they have similar sequence alignment and can inter-breed that is ALSO evidence of common ancestry.

    Well, it’s the same thing in both cases, so yeah. Creationists seem to accept the second but not the first. Perhaps you could explain why. Bear in mind that interbreeding is itself a test of substantial sequence alignment, because of the requirement for high sequence identity in F1 meiosis. Conversely, high sequence alignment does not guarantee an ability to interbreed, because it takes rather few genes to set up a reproductive barrier in principle.

    So the only thing that would be evidence of NOT common ancestry would be if one organism uses DNA copying and one uses a xerox machine.And even then, they still could have common ancestry, but branched so long ago, that it is hard to trace that common ancestor.

    If two organisms lack sequence identity, that is not evidence of common ancestry. This is that hypothesis testing thing again, rejecting the null or not, rather than ‘proving’ it.

    Anyway, you have scuttled to the far end of the spectrum again. We are not talking of organisms so different that the evidence is silent. We are talking of organisms on the cusp, just before and just after the origination of reproductive isolation if the evolutionary scenario is to be believed. There is high sequence identity on both sides of this divide. Why?

  50. Erik
    Ignored
    says:

    Allan Miller: 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.

    You don’t recall correctly. I only deny that microevolution is proof for macroevolution. And I also deny the claim that there is no distinction between microevolution and macroevolution.

    Because if microeveolution and macroevolution are the same thing, then “species” is a meaningless word. And Darwin openly aimed to make it a meaningless word, “the term species […] does not essentially differ from the term variety…”

    Microevolution, such as dog breeds, dogs as domesticated wolves, I don’t know if anybody has a problem with this. Contention begins from what goes beyond. The answers to this have boiled down to one thing: You already accept microevolution, therefore all species have common descent.

    Or do you have a different answer?

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