Examining the Fossil Record

Dr. Bernhoft, could you begin by defining terms? What exactly IS a fossil?

A fossil is the hardened remains of a plant or animal, preserved in rock. In order to become a fossil, a plant or animal had to die a long time ago, and be buried in mud or sand. Instead of just rotting away, the body of a fossilized creature was replaced by rock, with the same shape it had at the time of death. So you get a three-dimensional rock image of a plant, or part of an animal, maybe even an entire animal.

So you know what the plant or animal looked like when it died?

Exactly. Sort of like pressing a leaf between the pages of a book, only with rock.

So, fossils are like the "history of living organisms" written in organic remains instead of words. How far back can we trace using fossils?

Fossils go back about 600 million years, to the "Cambrian explosion" They appear abruptly, over about 10-20 million years; from that beginning point, you find fossils all the way through to recent geologic history.

Did Darwin consider fossils in his work?

Yes he did. He thought they were very important. But when Darwin wrote the Origin of Species 150 years ago, geologists had only recently discovered fossils. The existence of fossilized plants, animals, even exotic creatures like dinosaurs challenged many scientific and religious assumptions. Darwin's supporters looked to the fossil record for support for his theory of evolution. Darwin himself said that it was essential that fossils be found of ancestral creatures; he admitted that none had been found, but he believed that they would be. Believed, actually, that they had to be found, and that if supportive fossils could not be found it would disprove his theory.

OK, so Darwin basically DIRECTED us to examine the fossil records to test his theories. If we look at them, do we find a continuous record of development sort of intermediate species that are half one thing and half another?

No, we don't. Darwin said the fossil record should show gradual development from one form to another. But we don't see that at all. What we do see is a lot of big gaps between groups of creatures.

When a fossil appears in the record, it appears full-grown, so to speak, as developed as it is going to get, and that type of fossil stays pretty much the same either down to the present time (for creatures that are still alive) or until it disappears from the fossil record. There is no sign of the gradual development from one creature to another which Darwin said had to be found in the fossil record, if evolution is to be considered true.

Paleontologists scientists who study fossils call this tendency for fossil species to stay the same "stasis".

Define "stasis."

Stasis means that organisms suddenly appear in the fossil record, and then stay pretty much the same. They don't change, develop, or mutate into something else.

Let me make sure I understand you. Let's start at the beginning. As I understand it, living things developed in a particular order. They started with fish without backbones, eventually got backbones, and then evolved into amphibians, mammals and so on. Walk me through the fossil record here.

You're describing the so-called "evolutionary tree" that you often see in school textbooks. There isn't actually any fossil support for the evolutionary tree.

Stephen Jay Gould, the Harvard paleontologist you may have seen on PBS, points out that the so-called "evolutionary trees" that you see in high school textbooks are not trees at all; the connections between the various points are imaginary. All you have, according to Gould, are a lot of isolated points with huge gaps between them the connections are imaginary. There are no intermediate fossils between the points there is no scientific basis for connecting the dots.

What you see in the fossil record is a lot of huge gaps between families of organisms, without any sign of the intermediate forms which Darwin said you'd have to find if one species was developing into another.

What about that creature called the Coelecanth? I've heard that mentioned as a middle species.

The Coelecanth is a very strange-looking fish which many paleontologists thought based on the fossil record was an extinct creature midway between fish and amphibians, which died out 200 million years ago. Darwin, you see, believed that amphibians frogs, toads, salamanders evolved from fish.

The Coelecanth was thought to be a fossil midway between fish and frog until a French scientist bought one in the marketplace in Zanzibar, off the coast of East Africa. He took it home and found that not only is it not extinct, but it's just a funny-looking fish. No amphibian aspects to it, at all. And apparently it tastes pretty good. Folks in East Africa swear by it.

How about dinosaurs and birds?

Another interesting gap.

Orthodox evolutionary opinion holds that reptiles evolved into birds. There are a lot of problems with transforming a reptile into a bird not the least of which is the heart. Reptile and bird hearts are radically different, and it's pretty hard to imagine a heart midway between which would pump much blood. It's also not that easy to transform scales into feathers, nor to imagine an intermediate between scales and feathers that would serve any practical purpose.

There was great excitement last year at the discovery in China of what appeared to be a half-bird half reptile which looked like a cross between a small dinosaur and a turkey. Unfortunately, it now seems to Chinese scientists that bones from two different creatures have been combined; they don't fit together.

Was that fraud?

No, I don't think so. The Chinese scientific community is much less dogmatic about Darwin than we are in the West. The confusion just reflects the fact that fossils sometimes got buried together, sometimes violently floods, landslides, volcanic eruptions.

What about the lungfish, or platypus? Aren't they halfway between fish and mammals, or birds and mammals?

Not really.

The lungfish is a strange creature which lives in the East African desert. During the wet season, it is for all purposes a fish. It swims around and breathes through gills. But when the dry season comes, it hibernates in the mud, which dries out; during that season, it breathes through normal mammalian lungs. It isn't really an intermediate at all, but rather a mosaic it has mature fish organs, and carries mature mammalian lungs which it uses in the dry season, but it does not have any organs which are half fish/half mammal.

What about the platypus?

That's also a mosaic part mammal, part bird, but no halfway organs at all.

Earlier, you mentioned something called stasis. I think you said that stasis means that things tend to appear unchanged in the fossil record from the time they appear until the time they disappear. Can you give me some examples of that?

There are lots of fossils which go back a long way in the fossil record in some cases, hundreds of millions of years:

• various bacteria
• insect wings
• cockroaches
• horseshoe crabs
• squid
• certain snails
• ants
• bowfin fishes
• gars lungfishes
• sturgeon
• many frogs and toads
• crocodiles and alligators
• bats
• squirrels
• shrews
• tapirs
• opossums
• porcupines
• aardvarks

Unchanged for millions of years.

Right.

Textbooks talk about North American horses, drawing a tree with branches connecting one creature to the next. What about them?

Textbooks don't always keep up with scientific progress. I was talking recently with a biology student at the University of British Columbia who was taught last year the old idea that "ontogeny recapitulates philogeny" the idea that human embryonic development repeats evolution from blob to fish to mammal to human an idea which has been discredited for over 100 years, ever since its author, Ernst Haeckel, was censured for fraudulent drawings. But it's still in the texts at UBC maybe to help justify abortion, since few object to killing a fish or a reptile but not because of scientific validity.

So it is with the famous "North American Horse Sequence." It's still in a lot of texts, but paleontologists don't consider it valid. For one thing, there is not that much difference between the early and late parts of the supposed sequence. For another, the actual fossil record of horses is much more complicated than the supposed sequence might suggest. There is considerable overlap in size, shape and number of toes between the various "points" of the sequence, and most paleontologists don't think there is any sequence there at all. Many of the creatures in question also overlapped in time. There is certainly not a sequence of little, multi-toed ancestors evolving into big descendants with hooves, like the pictures suggest.

What about early man? We've all seen pictures of the "middle stages". What about Neanderthal man?

Most scientists now consider Neanderthal man to have been a modern man with rickets.

Isn't that a disease that people today can catch?

Yes. It affects how calcium builds up in the bones. That's why Neanderthal's bones look like they do. Cro-Magnon man another supposed ancestor is now thought to be just an early European. Same as modern Europeans.

There are no humanoid skeletons older than Neanderthal man.

There are a lot of bone fragments which people argue about; you may have read about the supposed humanoids from 3 or 4 million years ago, found by the Leakey family in Africa. If I recall correctly, they actually won a Nobel Prize for their work. But Sir Solly Zuckerman, who is a giant in this area and a Fellow of the British Royal Society, says that what the Leakeys have found are early ape skulls. And lots of other paleontologists agree with Zuckerman.

As for the charts you may have seen showing descent from one Leakey humanoid to the next and on to modern humans, even Mary Leakey who has done a great deal to publicize her family's humanoid fossils admits that they are not in sequence at all their bones overlap in time. They lived at the same time. They are not ancestors and descendants at all, just various apelike creatures which may or may not have been related.

But popularizers of evolution go off on tangents.

There is an artist named Burian who in 1952 painted Homo Erectus one of Zuckerman's apes to look black and apelike. In 1965, Burian painted Homo Erectus as lighter skinned, with more modern facial features. And in 1975, Burian painted Homo Erectus as hairless and caucasian in features.

Same bones, same artist, but a great "evolution" on canvas in only 23 years. Whether Burian's racial assumptions have evolved I cannot say.

There have been a few outright frauds as well: Piltdown man which was very famous after WWII turned out not to be a remote human ancestor, but a slightly filed ape jaw and some fossil teeth. Nebraska man was fabricated entirely from a pig's tooth.

Both, in their time, were defended by serious scientists.

Even more accepted specimens, like Java Man and Peking Man are now thought by many scientists to be apes related to the gibbon, and not human ancestors, at all. To complicate things further, Richard Leakey has recently discovered a humanoid skull older than the ones which made his family famous, but much more modern in type. His comment? "Either we toss out the skull, or we toss out our theories of early man."

No serious scientist is willing to draw a family tree for humans based on the available evidence. But you'll still see them in the school textbooks.

Is it just that the fossil record is still really incomplete?

Darwin and TH Huxley argued that the fossil record was incomplete, and that intermediate forms would eventually be found to support the theory of evolution. But as of now, there are 200 million fossil specimens representing 250,000 fossil species. 42 out of 43 living orders of land vertebrates have been found as fossils (97.7%) as have 261 out of 329 living families (79.9%). If you exclude birds, which don't fossilize well since their bones are so flimsy, it's 156 out of 178 living families (87.8%). In some regions, such as N Am, the fossil record is virtually complete. So although it is true that intermediates could still turn up, it is beginning to look somewhat unlikely that they will.

Is what you're saying a secret?

No. It's not a secret at all. Stephen Jay Gould calls the lack of intermediate fossils the "trade secret" of paleontology. He writes a lot in the scientific literature about the need for a new theory of evolution to explain away the lack of fossil evidence in fact, he has developed just such a theory involving huge jumps from horse to rhinocerous in one generation so to speak. But he hasn't shared any of that with the general public. As far as I am aware, he has never let the "trade secret" out of the bag on PBS. He just discusses it with his colleagues.

The scientific consensus is that there are huge gaps between species and groups of species, that there are no common ancestors and no intermediate fossil forms. The "evolutionary tree" is a fiction found only in school textbooks.

So, Darwin gave us a way to test his theory by using the fossil record. But Darwin's theory flunks Darwin's test. The theory doesn't fit the facts.

Funny that the standard of Survival of the Fittest doesn't seem to apply to the theory that coined the name.