From the Earth to the Geek

The Toronto Globe & Mail for April 2 reported that in an article in the April 2 issue of Science, researchers described an aquatic, salamander-like creature with arms that it would use to push downward to move through shallow rivers or to prop itself up while waiting for prey or to get air.

What's cool about this creature is that it lived somewhere around 365 million years ago.

At the time the creature lived, the late Devonian period, there were no vertebrates living on land; some 30 million years later, there were reptiles, birds, and mammals living permanently on land. The details of that transition are unclear, but this find from along a road cut in Pennsylvania of the world's oldest arm bone (an upper arm bone, or humerus, to be exact) is a major one that helps to bridge the gap between fin and limb.

Analysis of the arm bone, which is small enough to fit in the palm of a human hand, suggests a shoulder joint that would not allow a great degree of motion.

However, it would anchor a large muscle across the chest, enabling the tetrapod [a four-limbed animal] to produce a pushup or bench-press motion in a low, wide stance.

Fish also possess this kind of structure, but in a much less sophisticated design.

"This function represents the intermediate condition between primitive steering and braking functions in fins and the derived aquatic or terrestrial walking gait," the study noted.

Just over two weeks ago, I said this:

Evolution - genetic change over time in response to environment - is a theory. It's not a guess, not "just an idea," not a hypothesis. It's a theory. Not one easily tested in a laboratory, obviously, but one whose agreement with an enormous number of observations from biology, geology, and paleontology is overwhelming.

One of the reasons evolution is accepted by all reputable scientists is that every new discovery fits in the structure. Yes, there are gaps and questions, yes, there are arguments about details, but there is nothing that just doesn't fit, nothing that says "I don't work." I note this again because here we have another example: a new discovery that fits right in the scheme of things, indeed neatly fits in a gap.

And I say that offers more wonder and excitement than all the ignorance-peddling Bible-thumpers combined can conjure up.