Fossil fills gap leading into the development of land animals.

If you are a regular reader of Deep Thought, you may recall about how I blogged extensively on evolution and the recent trial in Dover, Pennsylvania. And even before that, I wrote Just science belongs in science class, about why evolution qualifies as science and in the absence of a scientific test, creation, intelligent design or others similar theories do not qualify, regardless of personal beliefs (my own included).

Now, proponents of I.D. often point out that evolutionary theory contains 'gaps' or 'holes' and as such it is an 'unproven theory.'

True, it does contain gaps and holes. And it has not been scientifically proven. I addressed this criticism head on in the linked post though:

Conceded that evolution is an unproven theory. But then, so are most theories in science (for example, no one has formally proven the Theory of Gravity either-- we just know it works as described by Newton). There is more and more evidence all the time to support evolution (be it the discovery of fossils, genetic experiments, observation of natural selection, DNA linkage, etc.) while I have yet to see any purported evidence that it is false that holds up under closer scrutiny.

No theory is proven or absolutely accepted as fact. In science theories are tested all the time. The idea that there is some sort of 'conspiracy' to always produce results that support the establishment theory is ridiculous-- becoming the 562nd scientist to carry out an experiment in support of established theory is not much of an achievement, but being the first one to come up with a way to show that it is either wrong or needs to be modified, is an achievement-- so scientists are always trying to disprove what has been postulated by other scientists.

And evolution has to be honest probably been the most scrutinized theory in the history of science. There are, in fact, many people who for either religious or other reasons desperately want to prove it false. And yet, every time I read a paper by one of them, the logic is just not there.

In contrast, the 'holes' that people like to point to in the theory eventually are filled in. And one of the biggest, the question of how fish evolved into amphibians and moved onto the land, just took a big leap forward in terms of being 'filled.'

NEW YORK - Scientists have caught a fossil fish in the act of adapting toward a life on land, a discovery that sheds new light on one of the greatest transformations in the history of animals.

Researchers have long known that fish evolved into the first creatures on land with four legs and backbones more than 365 million years ago, but they’ve had precious little fossil evidence to document how it happened...

It sort of blurs the distinction between fish and land-living animals,” said one of its discoverers, paleontologist Neil Shubin of the University of Chicago.

Experts said the discovery, with its unusually well-preserved and complete skeletons, reveals significant new information about how the water-to-land evolution took place.

“It’s an important new contribution to (understanding) a very, very important transition in the history of life,” said Robert Carroll of McGill University in Montreal.

The creature is called, Tiktaalik roseae and looks like a cross between a fish and a crocodile.

And in its discovery, evolutionary theory is tested. Following the scientific method, it establishes a hypothesis (prediction) that such a fossil (as well as others filling 'gaps' in the record) exists. Until yesterday's announcement, this was just an implied prediction, but if evolution were true, such a fossil would have to exist. So, it has been shown to exist, thus validating the prediction and strengthening the theory of evolution.