We, including you, do know that you are ignoring the evidence. Note that @John_Harshman cited evidence, actual fossils, which you ignored in favor of presenting as evidence, an abstract that itself didn’t cite any evidence.
…[quote=“Giltil, post:210, topic:16777”]
but if it is the case, I am not the only one, for he is not a creationist, not at all.
[/quote]
Labels instead of evidence. You seem to be convinced that examining any relevant evidence will not support your assertions. Is that correct, Gil?
In real science, rhetoric doesn’t do the convincing–evidence does. Perhaps you should consider evidence instead of rhetoric.
For my part as a scientist and Christian, I do think that those who go to great lengths to avoid examining evidence, pretending that science is a mere rhetorical exercise, are grossly deceiving others and themselves.
And in any case, when it comes to simplicity it’s a preference when all else is held equal. If a more complex theory also has much greater explanatory power we might actually prefer it over a simpler theory that fails to account for a lot of data.
Needless to say, evolution doesn’t even have a competitor. Anyone who thinks the theory is too complex is welcome to come up with a simpler one that explains all the same phenomena better.
Some may suppose that “God did it” is a simpler theory. It’s simple, but it isn’t a theory or even a well formed hypothesis. I’ve been trying unsuccessfully to extract such a hypothesis from proponents.
It happens that I’ve already explained my hypothesis several times on this forum. So let me sketch it again. Maybe in the grand scheme of life, some undifferentiated and archaic organisms in the past have functioned somewhat as stem cells in the development of individual organisms, giving rise to many different more differentiated organisms. Let’s call it the stem organism hypothesis.
That wasn’t an explanation. It was at best a vague metaphor*. Can you do better? Are you talking about individual stem organisms or about stem species? Where do these stem species or organisms come from? What makes them differentiate? And more importantly, can you provide any examples or any evidence that such things might exist?
What should be something of a clue is that your proposed saltational developmental process is not observed anywhere ever. We do however see evolution.
Saltational development isn’t employed in selective breeding and domestication of crops and livestock, evolution is. When species of viruses, bacteria, fungi, and innumerable other parasites, pests, and microorganisms adapt to novel challenges, such as pollutants, pesticides, and antibiotics, they don’t do it through this hypothetical differentiation-like process of saltational jumps, they evolve gradually through mutations and natural selection.
The only vague commonality here that I can see, is that your putative stem-organisms are supposed to function a bit like a last common ancestor of a specific clade. As in a species that gave rise to all subsequent species in the clade. But that’s about it.
Apart from the vagueness of that statement, isn’t the problem with your view simply that when we look at many, many lineages, we keep finding a “stem” behind everything, and that those stems converge as we go back in time? Heck, the cladists even use the word “stem” in a somewhat different sense to refer to parts of the evolutionary history of lineages. You can track all the mammals back to the mammal stem, and find they’re just modifications of basal tetrapods; you can track tetrapods back to the tetrapod stem, and realize that they’re just modified fish; and you can track all the fish back to the fish stem, and realize that they’re just modified versions of early chordates; and so on.
If these “stems” didn’t converge, of course, then this might point to life having originated multiple times. But they do, both morphologically and genetically.
If there were multiple origins, there should be evidence for that – and that should be positive evidence, not merely denials (built, in most cases, upon nothing but quote-mining) of the power of evolutionary processes to account for what we see. Where is this evidence of multiple origins?
It’s not entirely clear about @Giltil (another feature of his vagueness), but I think that Bechly’s saltationism, at least, features universal common descent.
One of the puzzles about him, for me, has always been that he allows himself to be made absurd by his association with the DI. It’s possible to be an iconoclast/crank/dissenter/whatever without associating oneself with others who are just outright mountebanks, and he does himself a disservice by that association. There have been any number of proponents, over the years, of one sort or another of hopeful-monsterism, but not all of them are so vigorous at destroying their own professional credibility.
I can’t say I know a lot about saltationism. However, let’s start from the premise that the fossil record is very incomplete and consists only of random “snapshots” of organisms that existed at widely separated periods of time. Is there any way that saltationism could be confirmed or refuted by such a record? It seems to me that, even if we assume saltation does not happen, we would still expect to find organisms who seem to appear “suddenly” with multiple new features, because the transitional forms have not been preserved or found. How would a saltationist distinguish such artifacts from actual instances of saltation?
One might ask an analogous question here to bring out the absurdity of what creationists, or saltationists, might claim about the fossil record:
To what resolution is the stratigraphic record complete? Is there a layer for every decade?
Not a geologist, so I assume there must be considerable periods where we simply don’t have any layers at all. Pick the time around when Tiktaalik existed, approximately 375 million years ago. Is there a layer that is 375.01 mya, 375.02 mya, 375.03 mya etc.?
I assume the answer is no, and that there are considerable periods where there simply are no layers at all. Creationists, and saltationists of whatever stripe, are basically positing that we cannot infer that evolution has taken place in periods where we lack stratigraphic representation, and that when there appears to be gaps in the fossil record, then either there was no life at all or that, one day an existing species gave birth to an entirely new and radically different one.
My stem species hypothesis doesn’t necessarily requires multiple origins. Let me offer you an analogy where the history of life could be seen as a sort of firework. A rocket A is ignited and at a given time/altitude, it explodes and diversifies, creating multiple bursts of color, sound, or pattern. But in this imaginary firework, rocket A continues its way in the sky. As it travels further in space and time, it becomes rocket B, and at a certain point, it explodes and diversifies again. Rocket B then goes on and becomes rocket C which, at a certain point, explodes and diversifies again. And so on. In my hypothesis, the stem species are analogous to rockets A, B, C, etc….
Depends on the size of the saltation, I would think. Is it hypothesized to explain every gap in the record? And if we find an intermediate fossil, does that falsify the saltation or just make two where there was previously one?
Yes, this is another way in which it’s too vague to be useful.
This would have certain consequences for phylogenetic reconstruction: you would see a tree that has a flurry of branches (a massive polytomy), with one branch later giving rise to another polytomy, and one of those to a further polytomy, etc. But this tends not to be what we see. Polytomies tend to have only a few branches, and most of the tree is generally found to be bifurcating. Of course you would have to identify a specific hypothesis of groups descended from these stem species, without prior reference to a tree, in order to test it. But identifying even one group that arose through saltation, or one that didn’t, seems beyond you.