One mutation at a time. No need for simultaneous mutations (since the mathematics verges on impossibility). But, maybe, by gosh, we do need those “simultaneous mutations.”
Here’s the abstract from Nature of an article where MCT (micro-computed tomography) reveals the ‘innards’ of a primary fossil. Just read it, and you’ll get the notion of how modern science is simply eviscerating Darwinism.
Phylogenetic analysis of early tetrapod evolution has resulted in a consensus across diverse data sets in which the tetrapod stem group is a relatively homogenous collection of medium- to large-sized animals showing a progressive loss of ‘fish’ characters as they become increasingly terrestrial, whereas the crown group demonstrates marked morphological diversity and disparity. The oldest fossil attributed to the tetrapod crown group [that is, the very beginnings of this supposed evolutionary divergence] is the highly specialized aïstopod Lethiscus stocki, which shows a small size, extreme axial elongation, loss of limbs, spool-shaped vertebral centra, and a skull with reduced centres of ossification, in common with an otherwise disparate group of small animals known as lepospondyls. Here we use micro-computed tomography of the only known specimen of Lethiscus to provide new information that strongly challenges this consensus. Digital dissection reveals extremely primitive cranial morphology, including a spiracular notch, a large remnant of the notochord within the braincase, an open ventral cranial fissure, an anteriorly restricted parasphenoid element, and Meckelian ossifications. The braincase is elongate and lies atop a dorsally projecting septum of the parasphenoid bone, similar to stem tetrapods such as embolomeres. This morphology is consistent in a second aïstopod, Coloraderpeton, although the details differ. Phylogenetic analysis, including critical new braincase data, places aïstopods deep on the tetrapod stem, whereas another major lepospondyl lineage is displaced into the amniotes. These results show that stem group tetrapods were much more diverse in their body plans than previously thought. Our study requires a change in commonly used calibration dates for molecular analyses, and emphasizes the importance of character sampling for early tetrapod evolutionary relationships.
IOW, we see a kind of “explosion” of body plans, a top-down radiation of species instead of the bottom-up (think of Darwin’s ‘tree’) radiation expected by Darwinism.
Here’s a quote from the PR:
“We used to think that
the fin-to-limb transition was a slow evolution to becoming gradually less fish like,” [Pardo] said. “But Lethiscus shows immediate, and dramatic, evolutionary experimentation. The lineage shrunk in size, and lost limbs almost immediately after they first evolved. It’s like a snake on the outside but a fish on the inside. . . .
The anatomy didn’t fit with our expectations.” . . .
“Many body structures didn’t make sense in the context of amphibian or reptile anatomy.” But the anatomy did make sense when it was compared to early fish.
“We could see the entirety of the skull. We could see where the brain was, the inner ear cavities. It was all extremely fish-like,” explains Pardo . . .
IOW, a “fish” became a “land animal.” Just like that.
Liberals could solve all the problems of the world if they had enough money. And Darwinists could explain everything about evolution if they had enough time—in the fossil record, that is.