At that point, we might as well throw every scientific theory out the window since they are all based on the same logic. Perhaps God only makes atoms behave as if they have electrons, neutrons, and protons. Perhaps God only causes planets to move about as if they are affected by gravity when in fact they are being guided by God’s hand. God makes rainbows in such a way that it only looks like light refraction is producing it when it is in fact due to God directly manipulating light.
Ann Gauger's latest salvo against Dennis Venema's arguments against an original pair of human beings
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Exactly. God could be even messing with our minds. I reject that sort of God, but some people might like the idea.
Steve
In comparing the two scenarios for which nested hierarchies provide support, you’ve been specific on evolution, but generic on special creation, along the lines of modern ID (where any sign of design will do) rather than Linnaean thinking.
In citing Linnaeus, I was being specific - he was guided by a long established (if now completely unfashionable) theological/philosophical foundation called the Principle of Plenitude. His intellectual generation believed that God must create every form that it was possible to create, or be unjust to the forms he missed out. Naturalists therefore expected to discover every possible species, and nested hierarchies were an entailment, not merely an option.
Linnaeus’s classification was at least in part to predict the gaps where new species would certainly be found - if not in distant lands, then somewhere on other worlds (whose scope had been massivley increased by the Copernican revolution).
If that seems esoteric, one needs to recall that the principle of plenitude was the direct source for Darwin’s repeated dictum “Natura non facit saltus”, an idea that came from Aroistotle’s scale of nature via scholastic philosophy. In effect, Darwin was saying that you need to look for the scale of nature in the chronological sequence of forms, thereby providing a philosophically naturalist alternative to Linnaeus’s “comprehensive design” philsophy.
So nested hierarchies do provide supporting evidence for common descent of a particular kind (they would be completely disrupted if a theory of predominant saltation were held). But since the specific theory Darwin sought to replace (and the alternative under discussion here) also treated nested hierarchies as evidence (to exactly the same degree) it’s not a useful apologetic argument for either.
In fact both evolution and Linnaean creation have leeway for hierachies being imperfect, the former because of “chance” events, the latter because of divine freedom. And both, as a result, have to deal with ambiguities - to return to Rieppel, he says that the phylogeny of turtles is even now disputed according to ones preferred methodology and presuppositions.
Point taken, AMW.
I’m not sure I was being unfair, though. Coyne is on record as saying that neither philosophy nor theology are sources of knowledge, so it’s not unreasonable to suggest that he may not be the most reliable person on those subjects. That’s before one mentions the strong criticisms on his understanding he’s received from biologists like the late Austin Hughes or Massimo Pigliucci, and a whole bunch of philosophers.
OTOH we’ve had on this very thread assertions made that ID supporters don’t do research - comments made directly to Ann Gauger, an ID researcher, which are therefore personally insulting to her. Not Snark?
Well, I guess my reading of Rieppel and the other cladists must be deficient, but I’m having trouble in following your train of facts here, without emplying logic to bridge the gap between the data of nested hierachies, which does appear to be a fact to me, and the conclusion of evolution, which appears to me to have the character of a deduction.
And that deduction in itself depends on a set of philosophical assumptions (rather like beaglelady’s assumption that Linnaeus’s God must be imitating the appearance of evolution, rather than the aopearance of evolution imitating God’s world of forms). The examination of these assumptions by cladists like Patterson (and others) led him to distinguish rather clearly (and controversially) the rigorous discipline of cladistics from the application of the results to a putative evolutionary history (which he agreed with, but as a conclusion, not as data/fact).
Why else do you think there was so much bitterness towards cladistics from mainstream biology in the early days? It’s all there, in the historical record.
But hey, I’m so stupid that when these guys write about the importance of “philosophy of science” they really mean “the fact of evolution”. At least you could credit me for reading their books and papers, albeit with a deficient understanding, limited education or whatever the problem is that prevents my understanding their apparently plain English.
Not more current that Linnaeus? But since we’re picking on minutiae, I concede that Humphries’ decease renders my description inaccurate, if not the argument.
Not sure what you mean. If you mean “evidence for evolution” that wasn’t the point. I was replying only to T aquaticus’s concession that Coyne does indeed use theological reasoning against Creationism , but that he also uses positive evidence for evolution, eg the existence of nested hierarchies. It was solely the fallibility of nested hierarchies as a proof of evolution to which I drew attention.
As an aside, one shouldn’t make the assumption that questioning the strength of arguments is a sign of unbelief in evolution, or unfamiliarity with it. One should be glad when one’s defence lawyer advises you of weak points in your presentation. Even apart from the last eight years spent commenting on BioLogos as a (critically conscious) theistic evolutionist, I’ve been studying evolution since university nearly 50 years ago, and even before that as a child.
Unlike some here I never had to rebel against imposed Creationism, so I don’t treat evolution as a sacred cow. Truth, however, is sacred.
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AMW
That dichotomy has been alive and well in the literature since 1927 when geneticist (and orthogenicist) Yuri Filipchenko, Dobzhansky’s mentor, first coined it.
Whenever anything more than one master-theory of evolution is admitted (think niche contruction, Evo_devo, structuralism) then the likelihood of different mechanisms predominating at different levels exists, and the terms “macroevolution” and “microevolution” are useful.
And surely we ought to have moved beyong the idea of a single Grand Theory of Evolution after the pattern of the Modern Synthesis of the 1930s?
Sorry to cite Rieppel again (having just read him), but he’s a historically-aware writer and puts these issues very well in relation to specific theories and their protagonists.
The Principle of Plenitude per se does not entail nested hierarchies. If one does not impose some other constraint, then it is trivially true that there are far more possible species than have ever existed, and species arranged in any nested hierarchy are a vanishingly small fraction of the total. In isolation, then, the principle would make a prediction that is completely inconsistent with reality.
Creationism based on this principle is only consistent with a nested hierarchy if it is coupled to an independent and very particular notion of “every form that it was possible to create”. Essentially, a nested hierarchy is evidence for creationism if species can only be created in a nested hierarchy. What is the source of that notion, independent of the observation that living things do fall into a nested hierarchy?
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Point taken, Jon Garvey.
In fact, I nearly retracted my comment just minutes after posting it, in light of the snark often shown by EC folks on BioLogos, which I hadn’t griped about before. But I thought, the reason I mention it to you is because it stands out. Meaning, you appear to take great care to make thoughtful arguments and present a winsome case, and then when the sarcastic zinger comes, it sort of poisons the whole post for me. I wanna say, “Dude… you know I was actually with you up until you had to go and assume the worst of your moronic interlocutors. That was an unnecessary turnoff.” This is just my experience. But it’s a different experience from reading some of the more purely snarky comments, where it’s “snark all the way down.” =)
Anyhow, have a good day!
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Ultimately Aristotle and Plato, but it was pervasive not only in mediaeval times but through to the eighteenth century, with echoes beyond. Arthur Lovejoy’s book The Great Chain of Being, though written back in 1934, is still maybe the best summary. The idea pervaded educated (and popular) society as much as naturalism does today (and taken for granted in the same way), and formed the basis of much of early-modern science’s research program, as well as, at the other extreme, Romanticism. It was even behind the English style of church-bell ringing, the idea being to ring every possible combination of your bells in emulation of the complete work of God.
By way of just one germane example, the naturalist Jean-Baptiste Robinet, writing his magnum opus between 1761 and 1768, wrote:
The activity of the Sole Cause is complete; in the product of this activity is everything that could exist… The work of the Creator would be incomplete if aught could be added to it… He has filled the fossil kingdom with all possible combinations… He has made all vegetable species that could exist. All the minutest gradations of animality are filled with as many beings as they can contain. The animal mind exists under all the forms fitted to receive it.
Robinet was one of the pioneers of evolutionary thinking, and partly, perhaps, because change over time increased the possibility of filling the gaps in plenitude, just as the possibility of other worlds had done in the previous century. Buffon similarly worked from similar principles in his challenege to the idea of species (as later adopted in Darwin’s initial argument in OoS), concluding that in the end the universe consists only of individuals (and hence every possible variety).
In fact, if one did the research, one would find that a great many ideas underpinning contemporary biology were conceived through the Principle of Plenitude, even though their intellectual roots have now been generally forgotten. It was probably that underlying assumption that even made it possible for Linnaeus etc to see nested hierarchies in the first place, beyond the similarities between creatures that had always been observed (but interpreted differently, so that bats were a kind of bird, and shellfish, starfish or jellyfish kinds of … fish).
The concepts of homology and analogy were well understood by the pre- (or anti-) evolutionary comparative anatomists before the general acceptance of phylogeny, and they were defined by Owen in 1843. The acceptance of evolution led to the idea that homology should be defined by common ancestry, and to the confusion between definition and explanation. (A L Panchen)
None of what you’ve quoted addresses the question at hand: why should all possible species form a nested hierarchy? Living things plainly do not form all possible combinations. There are no lizard-headed giraffes, 8-legged camels or hippogriffs, and Linnaeus didn’t expect to find them. Why not? Why the expectation that species should form a nested hierarchy?
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Aren’t “Nested Hierarchies” more or less a requirement or necessity if you are going to categorize living things?
Behold the Earth … okay, everything that has chlorophyl gets moved to the left, everything that doesn’t gets moved to the right; we’ll call that last bunch animals (for now).
Every animal with a vertebrate, gets moved to the left. And so on and so on.
What makes Nested Hierarchies so powerful in Evolution is that we should be able to estimate the genetic similarity of two life forms by how close they appear to be regarding their position in a common nested hierarchy!
Dunno. But Leibniz was a keen proponent of the idea, and maybe his “best of all possible worlds” idea is an explanation: what God created was all that (in his wisdom) was possible to create. The crocoduck, presumably, was doomed never to fly.
But I don’t know enough of the history to know if, as the world shrunk through exploration and the guys with the single big foor and the heads in their chest didn’t appear, whether people might have expected them to be on other worlds. If so, there would be nested hierarchies of hippogriffs and their sister-groups, I suppose.
No doubt they had their explanations, though, just as people in our times have explained the gaps by extinction (and some have peopled the ancient world with grotesque “failed evolutionary experiments” that cast doubt on the existence of a good God even when purely hypothetical themselves).
And the other side of the problem coin, as I said in an earlier post, is that both Chain of Being and Evolution have to account for homoplasy at macro- and molecular level. Lamarck, another “plenitude theorist” actually developed his “acquired characteristic” theory, according to Panchen, to account for homoplasy: nested hierarchies were dealt with by a natural trajectory through the forms. Actually my own reading of Lamarck agrees with that - he had two separate theories, for the hierachies and the exceptions to them…
It’s the central question, though. The issue is whether nested hierarchies should be considered evidence for creationism. If the only reason creationism expected nested hierarchies was that, well, we’re used to seeing nested hierarchies in living things, then they’re not entailed by creationism. Nested hierarchies are entailed by common descent, however (with the caveats I mentioned previously). Neither creationism per se nor an assumption of a great chain of being implies nested hierarchies.
The situation is qualitatively different for the two cases. The overwhelming majority of possible species do not exist; “astronomical” undersells how many possible species don’t exist, unless you assume the necessity of nested hierarchies. Exceptions to the nested hierarchy, on the other hand, are clearly exceptions to a pattern that is both clear to the casual observer and mathematically robust.
Sure. Any scientific theory of the diversity of life has to explain homoplasy. A good theory should explain them by mechanisms that are both plausible and testable, which evolution does.
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No. They’re a requirement if you choose to use a nested hierarchical description. The nested hierarchy of living things is an objective feature of Earth’s biology. We could still categorize living things if mammals had feathers.
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An astute observation, George, that touches on the distinction between natural classifications and classifications of convenience. Both create nested hierarchies, and extra lifting has to be done to correlate the pattern seen with natural reality. Linnaeus, it seems, was most interested in the “covenience” category - but with the ulterior motive that having everything classified neatly enabled one to have a complete inventory of God’s works and note gaps.
As Rieppel says, they’ve been arguing up to the present about which hierarchy in the turtle represents the real biological relation, between morphological and genetic, the patterns of different genes and development patterns and so on. Since none of the hierachies is perfect, and often disagree, there’s always an element of judgement in deciding which are natural and which are artifacts of your classification system. That was behind the movement of the “Pattern Cladists”, who refused on principle to draw any linkage between cladograms (data) and phylogeny (inference).
I suppose not many would take your specific example seriously enough to classify this sea slug as a plant, but the relations of Euglena have taken longer to untangle, means of nutrition having been one of the first things to be deemed an artificial distinction, even though intuitively obvious.
Richard Buggs of Kew, who first decoded the Ash tree genome (to combat ash dieback disease here) found that no less than 9,604 out of 38,852 protein coding genes were unique to ash, not found in species even in the same botanical order. Obviously the degree of specificity can only been known once every species is sequenced, but to the degree they are unique to taxa, orphan genes’ evolutionary relations are invisible or non-existent. At the same time, they show those taxa to be natural entities rather than gradualist continua.
But under a Creationist scenario, it would be possible to have a Nested Hierarchy of various phenotypes, with no genetic correlation at all.
What throws a wrench into the Creationist scenario is that the Nested Hierarchies on Earth seem to correlate all three of the following:
- similarities in phenotype correlating to
- genetic simlarities correlating to
3) the genetic basis of a “designs that are good enough” rather than
“designs that are always good”!
If God would go through the effort of making each and every creature through special creation, why would he include a weak anatomical or physiological design between two special creations?
The point of I.D. is that it is supposed to be Intelligent right?
So why would God break the Vitamin C gene in several primates and then copy the same "“stupid problem” into humans?
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If you tried to categorize vehicles you would find that they don’t fall into a nested hierarchy. The same for categorizing buildings, pieces of art, playing cards, and tons of other things. A nested hierarchy is unique to biology.
Even more to the point, humans can create species that don’t fall into a nested hierarchy. We have designed mice that have human and jellyfish genes. The same for fish. We mix and match genes from different species all of the time. All of these are clear and obvious violations of a nested hierarchy. So why are humans able to create species that violate a nested hierarchy, but God is not? Why couldn’t God create a species with three middle ear bones and feathers? Why couldn’t God create mice with exact copies of human genes just as we did?
So there is absolutely no expectation that special creation would produce species that fall into a nested hierarchy. None. However, a nested hierarchy is the only pattern that evolution can produce, given an absence or rarity of horizontal genetic transfer. This is why nested hierarchies are only evidence for evolution and not special creation.
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Not at all. If there were numerous and obvious violations of a nested hierarchy then we wouldn’t put them in nested hierarchies.
Playing cards are a good example of how violations can occur. Your first branch would be red and black cards. Each of those branches bifurcates into spades and clubs for black cards and hearts and diamonds for the red cards. So far so good. You then have to split up the suits into ranks, and that is where the trouble begins. You have an Ace show up in every branch where the common ancestor of that branch did not have an Ace. That is a clear violation, and it is true for all of the ranks. You can’t put playing cards into a nested hierarchy.
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Yet the fact remains, Steve, that entire generations of thinkers, including some of the early evolutionary scientists, didn’t see a problem with non-existent species, and based their research programs on a creationist principle of plenitude, which in at least some cases entailed nested hierarchies.
There may be good reasons for preferring an evolutionary explanation, but that’s a judgement on likelihood, not a question of fact.
The question of non-existent species being astronomical seems par for both courses still to me: there are maybe 150K fossil species and 10m living ones. If we follow the “99% extinct” guesstimate, non-represented species in the evolutionary past would be 6.6K to 1.