Richard Dawkins writes “The Lava Lizard’s Tale” in The Guardian:
The black lava fields of Santiago are an unforgettable – almost indescribable – spectacle. Black as a female marine iguana (of course the simile really should go the other way) the rock is called rope lava, and you can soon see why. It is drawn out and plaited in twisted ropes and pleats, folded and gathered like a black silk dress, coiled and whorled in giant fingerprints. Fingerprints, yes, and that brings me to the point of the lava lizard’s tale. As the lizard scuttles over the black lava of Santiago it is treading the fingerprints of history, rolled out by the sequence of particular events that tran-spired, minute by minute, on one particular day late in Darwin’s century, marking the minutes of that day, the day of the Santiago volcano.
There cannot be many other ways to see, laid out before you, a complete history, second by second, of one particular day, more than a century ago. Fossils do the same thing but over a much longer time scale. The molecules of a fossil are not the original molecules of the animal that died. Even fossil tracks, like those Mary Leakey found at Laetoli, don’t really do it. It is true that Laetoli shows you the exact places where two individual Australopithecus afarensis (those diminutive hominids carrying chimpanzee brains around on human legs), perhaps a mated couple, placed their feet during a particular walk together. There is a sense in which these footprints are frozen history, but the rock that you see today is not as it was then. That couple walked in fresh volcanic ash which later, over thousands of years, solidified and compacted to make rock. The lava ropes and pleats of Santiago, those giants’ fingerprints, are still composed of the very same molecules that were frozen into precisely those positions, only a century ago. And the time scale over which the distinct ropes and pleats were laid down is a time scale of seconds.
More here. And see parts one and two of this series here and here.