It's been a long time since I've responded to an Uncommon Descent post, and I'm starting to remember why. There's one that went up over there the other day on the fossil record that's really almost mind numbing - starting with the title, which is "Why Not Accept the Fossil Record at Face Value Instead of Imposing a Theory on it?"
Here's what seems to be the main argument:
Here’s a simple example – extinction estimates. Darwinists will say that 99.99% of species that have ever lived have gone extinct. Well, that’s actually a bunch of B.S. There are roughly 250,000 species that have been identified in the fossil record, and well over 1,000,000 species that exist today. Taken at face value, even if every species in the fossil record has gone extinct (which they haven’t), that means that 80% of species that ever existed ARE STILL ALIVE. That’s quite a stretch. So where do Darwinists get their number? By assuming that innumerable species existed in the transitional spaces. Why? Because they _must_ have existed there for their theory to be true.
You don't need to know anything about evolution to conclude that the fossil record is, by its very nature, spectacularly incomplete. You just need to know a little bit about sedimentary geology, a little bit about the process of fossilization, and a little bit about biology. When you take that knowledge and apply it to what we see on the planet, the conclusion that the fossil record is spectacularly incomplete is not just obvious, it's inescapable.
Let's look at just some of the major factors that lead to this conclusion.
Hard Part Bias:
Soft tissues fossilize poorly for a variety of reasons. They are more easily damaged, they decompose more rapidly, and they are often distorted by the weight of sediments that accumulate on top of them. Most of the fossils of soft-bodied organisms come from a very, very small number of sites. This is why the fossil record for jellyfish is very poor. It's why it took more than a century to figure out what kind of animal conodont elements came from. It's one of the reasons that there are entire phyla that have no fossil record at all.
Shells, teeth, and bones tend to stick around longer. They're tougher, and they're not as easy to eat. This means that the fossil record, as a whole, is very, very heavily biased toward preserving things that have hard parts.
If you doubt this, I'd suggest taking a walk along the beach. Bring a pad and pencil, and look at the shells you see there. How many are occupied by living organisms? How many are empty? And how many have something dead inside them. I'm willing to bet that barring really exceptional circumstances (like a very recent toxic waste spill) you'll find very few shells that contain the dead remains of their owners.
Fossils are found almost exclusively in sedimentary rocks. This means that the organisms that live in areas where sediment accumulates are much more likely to be preserved as fossils than organisms that live in areas where sediment is eroding.
The bulk of sediments are deposited into shallow marine environments, and the fossil record for these environments is comparatively good. Large lakes, dry basins, swamps, mudflats, and river delta complexes are other environments that tend to accumulate sediments, and we've got a fair number of fossils of organisms that lived (or, more accurately, died) in these areas.
Mountains, hills, and high plateaus, on the other hand, are not places where sediments are deposited. They're the places that sediments come from. Things that live in these places do not get preserved.
In the Late Devonian, there was a mountain range to the east of the Appalachians. We know this because it left the record of its existence in the rocks that we see in the Appalachians today - rocks that were clearly formed in shallow sea and nearshore environments that lay to the west of mountains. In a sense, you could say that the formations of the Catskill Delta are the fossil remains of the older mountains - but whatever might have lived there did not fossilize.
The movement of the continents throughout geological time creates and destroys major geological features. Mountains have come and gone. Sedimentary beds have been transformed under immense heat and pressure to such an extent that any fossils that they contained are unrecognizable. Islands in ocean basins - which tend to contain many unique species - erode away and are sucked down into subduction zones.
The Devonian mountains I just mentioned are one example of these processes - some of the metamorphic rocks that lay at their core are now exposed outcrops. Current mountain ranges provide us another example. When we look at fossil-bearing rocks along a cliff face, we're looking at what erosion has left us. Anything that was embedded in the rocks that eroded away before we got there has been lost.
The Hawaiian Islands provide another example of these processes. The current islands are the latest in a chain that's been around for a long time. The coral reefs of Midway atoll, way up the chain, sit on top of the remains of what was once a large volcanic island. The current large islands have large numbers of species that are found nowhere else in the world. When we look at other oceanic islands, we see that this is a common feature of isolated islands, so it's likely that Midway, and all the other islands that have eroded away as they've moved away from the hot spot, had their own unique species. But they, too, have left no fossil remains.
We know, for a fact, that there are enormous quantities of fossil-bearing sedimentary rock that we can't get to. Some of these rocks are located in places we can't reach. Most of it's buried underground.
When I was a paleontological tech, I would occasionally work with samples that came from deep wells. In some cases, the rock that I was looking at had been pulled from over a mile underground. I could look at the fossils that were in the core that the drillers recovered, but not at anything that was even a millimeter beyond the edges of the drill. There are tens of thousands of cubic kilometers of fossiliferous sedimentary rock under the surface of the Allegheny Plateau alone. If those rocks - which span a decent chunk of the Paleozoic - contain just one currently unknown fossil species per thousand cubic meters of rock, the total number of species just in that area would exceed the number of extant species by an enormous margin.
And let's not forget Antarctica. Any undiscovered fossil in the rocks that are currently buried under the ice there is going to remain undiscovered for a very long time.
This is something I actually explored the other day. As I pointed out then, ten thousand paleontologists working nonstop for 150 years at a rate of 2 cubic meters of rock per day are capable of thoroughly searching a miniscule percentage of what's out there.
This is why paleontologists are still naming and describing species. In the latest issue of the journal Palaeontology alone, there are a number of articles describing and naming new species from fossil remains. Just skimming through it quickly, I see two new trilobite species, a new bivalved arthropod, four new decapods, a new bryozoan, and three new bivalve species. Each of the papers describing the new species is the product of dozens, if not hundreds, of person-hours of work. And there's absolutely nothing special about the journal or issue I picked.
To sum all this up, we know that the fossil record is spectacularly incomplete. Based on the number of fossils that have been discovered, our understanding of the various biases favoring the preservation and of some forms of life over others, our knowledge of how much rock is out there that we have not and cannot examine, and our awareness of just how much effort it takes to find, identify, and describe just one new species, we can safely assume that the fossils that have been named represent only a very, very small fraction of the species that ever lived.