Considering the fossil record one might assume that if there was a transition from sea to land it must have been swift or there would be more evidence?
One might assume that but one would have no grounds for doing so. There is considerable--and growing--evidence for the sea-to-land transition of both plants and animals.
The discovery of Tiktaalik is an excellent example for two reasons: the undeniable morphologic evidence it provides, and the prediction-based method that brought about the discovery. The scientits who discovered the fossils
reasoned out where such a creature should be found if the ToE, and the sense the theory has made of prior discoveries, were correct. Lo! There it was.
All evidence is interpretable, but a large body of evidence narrows the range of interpretations.
If I find your fingerprints at the murder scene, I consider you a suspect, even though I know you had innocent reasons to be there at other times.
If I find gunpowder residue on your hands, I consider you an even more likely suspect, even though I know you often shoot at the local range.
If I find your DNA in skin cells found underneath the victim's fingernails, or the victim's blood spattered on your shoes, my interpretation of the other evidence begins to narrow considerably. Put enough such pieces of evidence together, and the most skeptical jury will hang you.
Any single piece of evidence permits diverse interpretations; a large body of evidence begins to take its own shape.
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