There’s a new study reported on at Phys.Org. This was a few weeks back. It seems that a “cousin” of a shark had a bony structure. And it appears that sharks FIRST had a bony structure and only subsequently developed a cartilagineous structure.
The lead researcher Dr. Martin Brazeau, from the Department of Life Sciences at Imperial, had this to say: “It was a very unexpected discovery. Conventional wisdom says that a bony inner skeleton was a unique innovation of the lineage that split from the ancestor of sharks more than 400 million years ago, but here is clear evidence of bony inner skeleton in a cousin of both sharks and, ultimately, us.”
Dr. Brazeau goes on to further say:
“If sharks had bony skeletons and lost it, it could be an evolutionary adaptation. Sharks don’t have swim bladders, which evolved later in bony fish, but a lighter skeleton would have helped them be more mobile in the water and swim at different depths.
“This may be what helped sharks to be one of the first global fish species, spreading out into oceans around the world 400 million years ago.”
So, per Behe’s First Rule of Adaptive Evolution, we see “loss of function” as the basis for a very pivotal adaptation in the history of evolved life-forms.
Isn’t it interesting how well Michael Behe’s “Rule” holds up, while Darwin’s “theory” is found impotent almost daily. What we see happening in sharks–if confirmed, is the opposite of Darwinian expectations. IOW, it was a “very unexpected discovery.”
EDIT: Here’s the paper as found on bioarxiv.