Another veil in the mystery of life on earth has been pulled back: scientists at Purdue and the University of Texas have uncovered a sort of ancestral history of RNA offloading some of its cellular functions to proteins.
This is fascinating stuff… and the fact that such new insights are constantly being generated is a big ongoing slap in the face for creationists of all stripes, who insist that we should just give up looking and experimenting. If we can’t explain exactly how in detail everything evolved, we should give up and admit that it happened by magic, right? Well, Dr. Barbara Golden and her colleagues decided not to give up, and as a result of applying evolutionary principles, they have increased our understanding of the world. And possibly even cast new light on our evolutionary past.
How does it all work?
The basic idea is that if life on Earth really is all part of a sort of biological family tree, then modern life should preserve some intelligible record of the various past branchings. Some species will come from branches that originated after a particular evolutionary change took place. Others will come from branches that are rooted prior to that change, meaning that they and all their descendants will lack that particular trait.
Thus, by looking in the right places (informed by the patterns that common descent suggests), you can potentially get real insight on just how particular innovations evolved, step by step. If we’re lucky, there will be modern representatives each major branch before and after some change. And because any one evolutionary change is unlikely to repeat in the same way twice in two or more different lineages, these genetic contingencies are often still distinctive no matter how much additional time and change has occurred.
Here’s my artless illustration of the sort of patterns these researchers are looking at:
Now, creationists and Intelligent Design fans are welcome to scoff and dismiss this sort of research. No, this isn’t the same as certain proof that this is definitely how it happened historically: it’s just an illustration of why the idea is plausible. And no, it doesn’t explain everything. It may not even pan out in and of itself.
But this naysaying is still just defensiveness: if the creationist/intelligent design spin on biochemistry is correct, research like this shouldn’t even be possible, much less plausible, much less real.
If the RNA in various species never evolved, in some actual historical progression of events, from performing chemical functions itself to having proteins take over its tasks, then there’s simply no reason at all for the sorts of harmonies and ancestral patterns that these researchers are describing. There should be no hint of branching differences revealing intermediary steps in precisely the order that common descent would imply. There shouldn’t even be a way to form a family tree of life out of both living and extinct species. There’s really no reason any of it should fit together at all, much less in the very, very distinctive pattern of ancestry.
And it’s not like they have anything better to offer in comparison…