Why I wrote about 10 icons of evolution in my book. I could have written about more but I had to stop somewhere. The ten that I wrote about were first of all the 1953 Miller-Urey experiment that purported to show that life could have begun spontaneously on the early earth. And this is still found in most biology textbooks even though geochemists decades ago decided that the experiment was unrealistic and really doesn’t say anything substantial about the origin of life.
The second icon was Darwin’s tree of life – the branching pattern that would show how all organisms descended from a common ancestor at the root. And this is a theoretical statement but it’s presented in most biology textbooks as though a fact. The fossil evidence for example does not show this branching tree pattern. When you look at the different major groups of animals, they appear pretty much at the same time rather than diverging from a common ancestor.
The third icon I wrote about was homology in vertebrate limbs. If you look at the bone structure of the human hand or the human arm and you compare that to a whale’s flipper or a bird’s wing or a bat’s swing, there are certain striking similarities in the bone structure. And Darwin considered this to be a result of common descent. But people before Darwin had noticed the same thing and they attributed it to a common designer. The truth is: it could be either one. The bone structure itself doesn’t tell us.
The fourth icon is Haeckel’s embryo drawings, which purport to show that vertebrates are very similar as early embryos and therefore this provides evidence for common ancestry. But in fact the embryos are not similar and Haeckel faked the drawings.
The fifth icon that I wrote about was Archaeopteryx, a famous fossil of an ancient bird that had a long tail and teeth in its beak like reptiles and for a long time was thought to be the missing link between reptiles and birds. Biologists no longer think that because there are too many differences between Archaeopteryx and modern birds but textbooks tend to present it as the missing link anyway. The peppered moth is a famous icon of evolution in which moths supposedly changed color during the Industrial Revolution because dark moths were better camouflaged on soot dark and tree trunks and the birds couldn’t see them so they ate the light moths and left the dark ones. And this is still used in many textbooks as a classic example of natural selection in action when in fact biologists discovered in the 1980s that peppered moths don’t rest on tree trunks in the wild at all or normally. And so the textbook pictures have all been staged and the story has serious flaws. Darwin’s finches, another icon of evolution, are some species of birds on the Galapagos Islands that are very similar except for the size and shape of their beaks. And it’s thought and it’s quite possible that they evolved from a common ancestor because of having to eat different foods on the different islands. But the actual evidence shows us only that the beaks can change over a matter of years based on climate and diet but the changes are temporary. They oscillate back and forth and they don’t go anywhere. So as evidence for the Origin of Species, Darwin’s finches really don’t work. Another icon of evolution is the four-winged fruit fly. Most fruit flies have two wings but a series of mutations in a fruit fly can cause it to develop a second set of wings. Very normal looking but in fact there are no muscles attached to it so the second set of wings is effectively dead. The fly is hopeless. It’s kind of like having a small plane with an extra pair of wings tied to its tail. This is not the forerunner of a new race of insects but an evolutionary dead end.
The last two icons I wrote about were fossil horses and the ape to human picture. In both cases, there is some real evidence here. The important point in both of these icons is that a very heavy dose of philosophy is laid onto the evidence. In each case, mainly to persuade students that evolution is without direction or purpose, in the case of the ape to human icon, students are also told that humans in effect are nothing more than animals. Neither one of those claims comes from the evidence. Both of those are philosophical claims but they use the evidence to make themselves appear more scientific than they really are. And so that’s my criticism of those two icons. I have to assume that we have no reason not to think that in the Cambrian we can see animals that are just like modern arthropods in their body plan, just like modern vertebrates, just like modern mollusks, various kinds of worms, echinoderms which include the starfish. When we watch them develop today, we have no reason to think that similar animals in the Cambrian didn’t develop the same way. That’s why the Cambrian fossils are recognizable in most cases as members of modern animal phyla. So the complexity is already there, full blown right from the start. And if the complexities are there, then the complexity of development is also there because presumably these animals all developed from a single fertilized egg. And so the processes we see now, we can I think legitimately extrapolate back to the Cambrian. Before the Cambrian, whatever forms of animal life we had were far simpler than what we have in the Cambrian. So the genetic materials to support the diversity of life in the Cambrian had to appear rather suddenly. It was an explosion of genetic information, very real and I think inexplicable on Darwinian terms.
But there was also an explosion of information of another sort and that’s the information that gets us body plans. The body plan as far as we know is not in the DNA. For example, we know a lot of genes that play roles in development that are very similar in fruit flies and humans and yet fruit flies and humans have totally different body plans. It turns out that those genes, the most impressive ones, the most dramatic ones, are active fairly late in embryo development, long after the body plan is established. So whatever is establishing the body plan, it’s something else and there obviously had to be an explosion of body plans as well as an explosion of DNA information.
Certainly DNA is essential. You cannot get an animal without the proper DNA but developmental biologists know that there’s a lot more to development than the DNA. We sometimes hear the notion of a genetic program where the DNA is the blueprint for the organism. That’s quite a common image but in fact we know that there’s a lot of information for development that’s not in the DNA. So properly speaking, the DNA is not the blueprint; it’s more like a parts list. The DNA provides the animal body with proteins and RNAs and other chemical constituents but the DNA does not dictate the form of the animal as far as we know. House is another good analogy for the way DNA functions in the cell. The DNA is like a parts list. I could create 10 different piles of building materials, all of them identical, all of them with lots of lumber and piping and wiring and nails and roofing and cement and so on, same thing in each pile and give each pile to a different person and send them off where they can’t see each other and say “build me a house”. And the odds that any two of those houses would look the same are very slim because with the same materials you can build all kinds of structures. And it’s the same with the cell. The DNA provides the building materials or the list of building materials but then the cell decides the floor plan. The floor plan is somewhere else because to build a house you can’t just have building materials, you need actually assembly instructions, you have to do things in a certain order. If you build the roof first, you’re in big trouble. You have to put the foundation in, the walls, the piping, the wiring. You need a certain sequence here. And you need a floor plan to know how to lay out the floor and the walls to begin with, where to put the windows. And the DNA gives us the list of parts but the rest for the most part – certainly the floorplan – is somewhere else.
We’ve known all along that most mutations are either harmful or neutral (neutral meaning they don’t have any noticeable effect, at least not right away). But really beneficial mutations, which would be the only kind evolution could use anyway, are extremely rare. Furthermore, they are biochemical in nature. For example, in antibiotic resistance – we know mutations can lead to antibiotic resistance – and then those bacteria can survive in the presence of say streptomycin where others could not. But the bacteria that survive are still the same species of bacteria, still tuberculosis for example. So even the rare beneficial mutations we find do not really transform the organism. They make minor changes within existing species, which have never been controversial. And of course the evidence for mutations has already suggested that to us. I can take a fruit fly embryo – and this has been done in fact – and it can be mutated in every possible way the DNA. And there are only three possible outcomes – a normal fruit fly, a defective fruit fly or a dead fruit fly. That’s it. You can’t even change the species much less get a horse fly or something like that.
We’ve certainly found a lot of evidence but for what Darwin’s theory is, that all living things are descended from a common ancestor modified by unguided natural processes such as natural selection and variation, Darwin didn’t write a book called “How existing species change over time”. That’s not even relevant. People have known that for centuries so minor changes within existing species are not the issue here. And yet when Darwinists say that there’s overwhelming evidence for Darwin’s theory, 90% of what they talk about is minor changes within existing species. That’s not the point at all. The point is the origin of new species by this same process and no one has ever observed the origin of a new species through variation of selection and they’ve tried. They’ve tried many times but that key element in Darwin’s theory – the origin of a new species – the title of his book has never been solved. Now the common ancestry part, the argument for that, is usually based on similarities and differences like I have certain similarities to this animal or that animal and certain dissimilarities which show this or that. Those arguments are interesting but they’re not conclusive. Because you can argue the same way on the basis of common design. I look like this and not like that because there’s a design reason for that. You can do the same with cars. In fact, Darwinists have used car models as an illustration of descent with modification but cars are designed, they’re created by engineers. So until you get this one important step where one species can originate from another species, why should I accept common ancestry at all? Because the mechanism is not there. The similarities and differences can cut either way but what we’re totally lacking at this point is good evidence for Darwin’s basic mechanism.