Yes, of course, especially if you’re thinking about the record in any one area. And the distribution of taxa being limited in space as well as time, it does little good if the time missing from point A is found half-way around the world at point B.
I should add that the fossil record doesn’t even have to be missing in some area; a change in environment could locally eliminate many species that continue to survive in some unsampled region, or show the sudden appearance of many species that could have been found in that unsampled area.
As @Roy and @AnEvolvedPrimate said, that’s basically evolution. How does it differ? I suppose it might differ in the way @John_Harshman suggests, with a series of massive polytomies, but I took your “explodes” term to simply mean an adaptive radiation of the type we typically see in the fossil record, which would not require any polytomy. (And, of course, he’s right. We don’t see huge polytomies, and that’s probably because they are not real but are artifacts of the limits of our evidence; if two bifurcating events happen closely together, it’s not necessarily possible to say which of them happened first.)
It’s fair to say that the fossil record does show adaptive radiations. They tend to be the product of ecological opportunity and things like that – for example, you get a huge mammalian adaptive radiation after the dominant large fauna are comprehensively exterminated in the K-Pg event. But the fact that adaptive radiations happen is not a challenge to, but rather an illustration of, evolutionary processes. And so I am having considerable difficulty seeing how your “stem species” notion is different from conventional evolutionary explanation at all.
That’s because it’s so vague as to be compatible with almost anything. I suspect his model has some unstated features: most importantly, that God causes the saltations and that otherwise they would be impossible; also, I do think he envisages a stem species giving rise to many independent saltatory events, pretty much all at once.
Yeah, that seems to be true. And it means that one can carry on never defending a position, because there’s no position to defend, while contending that the scientists have got it wrong. I don’t know about Giltil, but I’d be very unhappy to find myself in that sort of nihilistic zone. Surely at some point, if one cares about the origins of living diversity at all, one has got to have some kind of idea or understanding of the ideas of others which can be characterized meaningfully.
To the ID-proponents and creationists, this was never really about getting the history of life on Earth right. It was always about trying to create some sort of platform on which to instigate a deeply socially conservative and fundamentalist religious revolution.
One possible difference is that in @Giltil’s rocket scenario, every ‘explosion’, i.e. diversification, is on a single lineage, rather than each lineage having the potential to radiate independently of the others. Rather like the great chain of being, instead of the evolutionary bush. So the ‘explosion’ that resulted in the radiation of bird species would have to be on the same lineage as the radiation of mammals, for example - and the same lineage as the radiation of flowering plants. Though it’s also possible that he, like many creationists, simply doesn’t know or care about any lineage other than the one leading to humans.
Well, yes. But I still might think that individuals who take a particular interest in the “controversy” would want to have SOME idea beyond a mere negation of evolution as to what they think happened (and happens). I know that if I somehow came to believe in extreme saltationism, I would think that a thorough familiarity with the fossil record would be the first thing I would try to learn. I cannot imagine advocating for that view for years without ever bothering. It would be embarrassing to be constantly caught short of relevant facts.
I’ve lost count of the creation/ID advocates I’ve seen who are completely unembarrassed when caught posting vagaries, blather, falsehoods, copied rubbish, misquotes or even outright lies.
It’s as if being ‘right’ (aka invincible incompetence) means never having to say sorry.
I’d like to point out that @Giltil has posed a hypothesis that appears to be testable (perhaps with some modifications already suggested). So it’s probably wrong, but this too is science.
Has he? Shouldn’t it make an explicitly, concrete, and unambiguously measurable prediction that is observationally distinguishable from competing alternatives, to be testable?
How would you test it? What are the observable differences from the usual evolutioniary scenario? This thing needs a whole lot of work before it rises to the level of “testable”.
Has he? Shouldn’t it make an explicitly, concrete, and unambiguously measurable prediction that is observationally distinguishable from competing alternatives, to be testable?
It needs a little help. I think @Roy’s suggestion #227 is one way to approach it - and (I predict) also quickly rejected by phylogenetic models comparing it to Common Descent.
My point here is that Gil has gone out on a limb to pose a hypothesis that (with a little help) could be testable. This is not any great development in evolutionary biology, but it’s a huge step for a Creationist. I do not intend faint praise - imagine if every Creationist could do the same.
Like others, it is not clear to me how this differs from the standard evolutionary model of common descent. Would your scenario be represented differently than in the phylogenetic tree below? In your hypothesis, would the six bird species shown all be connected thru straight lines originating from a single point, rather than thru a branching tree pattern as shown?
But is that different from the standard evolutionary scenario? We could draw a lineage from the LUCA to human beings. Along this line, there would be an “explosion” leading to flowering plants that occurred 1.6 billion years ago, then another leading to birds 325 million years ago.
Of course, if you draw the lineage with birds at the end, then we are the ones “exploding off” at 325 mya. And a lineage leading to plants would have an “explosion” occurring 1.6 billion years ago that included mammals and birds, along with everything else that wasn’t in the plant kingdom. But, as far as I can tell, that is no different from @Giltil’s “hypothesis.” There, the explosion that led to flowering plants could also have been the origin of a lineage that eventually led to both birds and mammals. It is merely arbitrary which lineage is considered the “main” one, and which the “explosion.”
If I had to guess, I would suspect @Giltil believes his hypothesis is depicted by the diagram on the left below, while the other two represent evolution. Whereas, of course,they are all the same tree.
Yes. In the above scenario, all the explosions are on one lineage. Rocket A becomes rocket B, rocket B becomes rocket C etc. Only the main line can branch; no branching of other branches. Evolution includes rocket A becoming rocket B and, separately, rocket C. Any lineage can branch, not just one.
Yes, that matches my understanding as well. Which raises the question of what difference is there in his hypothesised ‘stem species’ that allows them to explode, and in the ‘non-stem species’ that prevents them from diverging? It would seem that, in order for this ‘hypothesis’ to be anything more than untethered speculation, some sort of mechanism that has at least the potential for doing this would need to be proposed.
Would it be unreasonable to speculate that this hypothesised mechanism would need to ensure that the bulk of the genetic diversity in the original stem species went with its descendant stem species (allowing it to further ‘explode’) rather than to the non-stem offshoots? How does this mechanism match what we know about the mechanisms of speciation?
Well, let’s unpack things here.
From Bechly’s piece, I inferred that Müller has acknowledged that the fossil record documents non gradual forms of transition. Here is the relevant passage of Bechly’s piece: One of the main proponents of an extended synthesis is the Austrian scientist Prof. Gerd Müller, who held a very revealing keynote at the conference New Trends in Evolutionary Biology at the prestigious Royal Society in London in November 2016. In his keynote Professor Müller showed a slide that introduced five explanatory deficits of the Modern Synthesis, which is just a synonym for Neo-Darwinism (Müller 2016, Bechly et al. 2019). Among these five explanatory deficits, which Neo-Darwinism fails to explain, he listed phenotypic complexity, phenotypic novelty, and non-gradual forms of transition (emphasis mine)
Now, I recognize that from the above passage alone, my inference was not warranted, for the non-gradual forms of transition Müller mentioned are not explicitly associated by him with the fossil record.
However, in the piece you referred us to at 192, one can see that Müller devotes a lot of his time discussing the underlying causes of the non-gradual forms of transition. IOW, his piece is mostly about the causes of the discontinuities, not their consequences on the fossil record. But isn’t the case that these various causes of non-gradual forms of transition that Müller cites will be reflected in the fossil record?
