And for
@1Tonne I don't know what's going on in your thread there with people stalking you. But in response to your last post:
"
Even if some phyla appeared before the Cambrian, the explosion still represents a sudden surge of complex body plans with no clear evolutionary ancestors. How do you explain that?
If these phyla existed before the Cambrian and still exist today, doesn’t that suggest that they haven’t fundamentally changed? Wouldn’t evolution predict more transitions rather than stable body plans for hundreds of millions of years?"
Its not sudden. It spanned tens of millions of years.
And no, it doesn't suggest that they haven't fundamentally changed because phyla are such a massive category or animals. Like chordates. They existed back then and exist today, but this encompasses a very large array of species.
"
Even if the Cambrian explosion spanned tens of millions of years, the key issue is the sudden appearance of diverse, fully-formed body plans"
This is of course contradictory. Because tens of millions of years is not "sudden". They didn't all just "appear" suddenly. Rather these species are observed in the fossil record at various points along tens of millions of years of rock layers. And observation in the fossil record should not be confused with animals "appearing" into exist or something weird like that. Because we know that fossilization follows certain patterns and likelihoods based on things like environmental conditions and the nature of the species being fossilized.
Obviously no one would expect soft bodied Precambrian species to fossilize as readily as hard shelled and hard toothed Cambrian species. So you'll naturally find these "appearances" of hard-shelles animals in the fossil record, even though realistically they were already there, soft bodied, beforehand as well in earlier times (which is why we have things like genetics, and other forms of evidence, like trace fossils, that additionally affirm this). The "appearance" being more of a product of conditions of fossilization, as opposed to an actual material ex nihilo appearance out of nothing of animals.
"If evolution is correct, we should see more fossils from the Precambrian showing transitional forms that lead to the sudden diversity of the Cambrian period."
Not necessarily. As noted before, ancestral species were oftentimes microscopic and soft bodied. Which means that the fossil record would more than likely disappear as you go back deeper and deeper in time. The smaller animals get, the softer they get, the older and more recycled and melted the rock gets via plate tectonics, the fewer and fewer fossils you'll have.
That doesn't mean that animals just appear out of nowhere, it just means that fossilization becomes more and more rare when you start getting back into hundreds of millions, or even billions of years old of time.
And that's why the best examples of the fossil record we have are from more recent times, like in the past 50 million years. We have things like elephant fossil sequences and horse fossil sequences that are extremely well detailed, and that's because they haven't had time to degrade and be destroyed by geologic processes, And these animals are much larger than precambrian species that may have been the size of our pinky or smaller, an elephant is the size of a trailer home. So we have this difference in size, difference in fossilization conditions, difference in morphology of animals, elephants have hard tusks. Many pre-cambrian species were soft like jellyfish.
So the answer is actually the opposite of what you're saying. If evolution is true, we should not actually expect super ancient metamorphosed rock to contain a detailed fossil record of soft bodies tiny organisms.
"
How can we explain this dramatic surge in complexity within the time frame we see?
What mechanisms do you think would have caused such rapid and diverse changes in such a relatively short period of time?"
Tens of millions of years is an incredibly long amount of time. And as noted before, things like the opening up of new niches allows for diversification of species into new environments. And I mentioned things like the rifting of rodinia and the end of snowball earth, which serves almost like an opening of floodgates for new niches for animals to fill. You didn't seem to like this answer, but it's not my job to respond to your incredulity. I think that it's a perfectly reasonable explanation.
"
Macroevolution, however, refers to the evolution of new species or higher taxonomic groups. While both processes involve genetic changes, macroevolution implies significant changes that create entirely new forms of life. The distinction is important because while we see microevolution happening around us all the time, macroevolution, the kind of change that leads to new species or genera, hasn't been observed in the same way, particularly when it comes to the fossil record."
Id disagree here. Speciation has been observed, ie macro evolution:
"
Could you provide examples of clear transitional forms leading up to the explosion? "
Sure.
Here is an example of a Precambrian species, Haootia quadriformis, interpreted as a muscular cnidarian, proceeding Cambrian cnidarians of the Cambrian explosion such as dinomischus, Archisaccophyllia, or Cambrorhytium.
And I'll just say this up front; God of the gaps arguments are not valid arguments against paleontology.
If you have these well detailed transitional sequences of things like elephants, tetrapods, birds, or horses (more modern well preserved sequences), it's not really valid to say, well let's look at the most ancient rocks (highly metamorphosed and recycled) and let's look at the most ancient microscopic and soft bodied life forms (less likely to fossilize) and let's use that to determine if the fossil record supports evolution.
That's kind of like backwards creationist logic.
That's more of a dishonest approach I'd say. So, while I don't mind looking at ancient fossils, obviously nobody bases their understanding of the fossil record on Precambrian soft bodied ediacaran.
The best way to determine the fossil record's support of evolution really is to look at more recent sequences of macro or large vertebrates. Like elephants, or whales, or tetrapods etc.
It's like if you have Micheal Jordan, the basketball player, you don't judge if Michael Jordan was a good basketball player based on his high school or grade school skills, you judge him based on the most recent and highly detailed records of his career.
God of the gaps has never been a reasonable approach to YECism or any form of creationism because it never actually includes its own positive arguments. It always relies on and falls back on personal incredulity (I don't feel comfortable with the precipice, the deepest and more ancient details, and further extent of science, therefore insert God in that gap). You don't want to just insert God at the furthest edge of science. Because when science makes a new discovery, God will just keep retreating. And getting smaller and smaller as science advances.
And that's what intelligent design attacks on evolution are. They're just modern versions of God of the gaps. The same old arguments, rehashed over time just with new language and new approaches. But God of the gaps was never a valid approach to science or to scripture.
And I'll add
@River Jordan here as well. On concepts of theistic evolution.
And I'll just throw this in for good measure (because creationists have no response for it), Genesis describes ancient Israelite cosmology. So, whatever reason it is that you have an issue with evolution, it doesn't have anything to do with the Bible. Genesis is not a science textbook:
