Adam and the Genome 2: Chapter 1- Evolution as Scientific Theory
We continue our review of the book, Adam and the Genome: Reading Scripture after Genetic Science, by Dennis Venema and Scot McKnight. Today, chapter 1.
Dennis begins this chapter by reminiscing about his childhood love of science. He grew up in northern British Columbia (that’s in Canada for those of you from Rio Linda) and spent a lot of time outdoors with his father and brother. He developed a great love and wonder for the natural world and a desire to know it better. While other kids wanted to be policeman and fireman, he wanted to be a scientist. He notes:
“Real science, as I understood it from my private-Christian-school workbooks, matched up perfectly with what God said about creation in His Word. “Darwin” and “evolution” were evil, of course—things that atheist scientists believed despite their overwhelming flaws, because those scientists had purposefully blinded their eyes to the truth. I distinctly remember that even hearing those words said out loud felt like hearing someone curse, and not mildly.”
It is important to note this, because many feel that people believe in evolution because they have been “brainwashed” by secular liberals, whether raised by secular parents or from teachers in secular schools. But Dennis’ “brainwashing” was the opposite typical of fundamentalist or conservative evangelical variety. Since his parents couldn’t afford private Christian college he was off to the “secular” university with prayers from his pastor and congregation that he would not lose his faith in the process. And it still wasn’t until after graduate school that he finally came to terms with evolution. The process that began to persuade him was earning an honors degree and writing a research thesis. In his own words:
“It changed everything. I was working on an open scientific question, one without a canned textbook answer. To address the question, I needed to understand the principles of developmental cell biology, genetics, and how gene products work at the molecular level. I was designing experiments to test hypotheses, and troubleshooting them to get them to work properly. For the first time I was doing real science, and I was hooked.”
And this was the epiphany that many of us who are scientists have had: that science is a slow, step by step process of understanding the underlying principles that tie the facts together into a coherent whole. In the common parlance a “theory” is just a guess or a speculation i.e. “I have a theory that aliens helped build the pyramids”. But in science a theory is what facts grow up to be. A theory is the explanatory framework for why the facts are the way they are.
So when the average uninformed Christian says, “Evolution is just a theory”, they mean that in the common parlance. But in science evolution is a theory the way gravity is a theory. No, we don’t know exactly how or why gravity operates the way it does, dimples in the space-time continuum and all that, but we know the theory explains how bodies of mass are attracted to each other. Think evolution is just a theory, fine, think gravity is just a theory, step off a cliff and you’ll quickly (at 32 feet per second per second) find that the theory is not falsified. Wait, don’t you mean—proved? No, and this is the next very important point Dennis makes.
Scientific hypotheses (theories in infanthood) are never “proved” they are only “not falsified”. They are not falsified until the next experiment is done, the next prediction is made, and the next discovery is uncovered. If, based on your hypothesis, you predict A should happen, and then you find B happened, you must, if you are a good scientist, go back and modify your hypothesis to take B into account. So then a hypothesis that is not falsified after many, many predictions and tests eventually grows up to be “a broad explanatory framework that has withstood repeated experimentation and that makes accurate predictions about the natural world: in other words, a theory (page 4)”.
So a scientist never “believes” in evolution, they simply accept it provisionally, as the best current explanation for the facts at hand. This is where many apologists for evolution go off the rails, as I’ve seen time after time, in discussions. The theory of evolution has abundant proof for over 150 years, they’ll say. Their interlocutor will come back and say, give me one shining example of absolute proof of evolution. And the evo-apologist will flail around with “homo Naledi” or “Lucy” or archaeopteryx. Then the interlocutor will scorn, that’s your PROOF; Lucy was an ape, archaeopteryx was a bird, you’ve proven NOTHING. And you know what, they are right, you haven’t PROVEN anything. You, and they for that matter, have failed to reject the hypothesis. That is all. But it is enough. Because time after time, bone after bone, fossil after fossil, gene after gene the hypothesis has failed to be rejected. So there is no knock-down, slam-dunk evidence for evolution there is only the slow, cumulative, failure to reject the hypothesis.
Another problem that it seems has recently gone from bad to worse is the reporting of science in the media. The media loves to spout the headline of “overturn previous theories” or “changes everything we though we knew”, but, as Dennis points out, this is so often misleading. Of course, these headlines are often about dietary science, which has become, let’s be frank, a racket. Dietary research is naturally interesting to everyone since we all want to lose weight and stay healthy, but is very difficult to do right, and very easy to exploit. The very term “snake oil salesman” refers to the peddling of a dietary supplement.
Dennis then recounts the infamous story of Johannes Bohannon, PhD and the study published in the spring of 2015 about how eating chocolate would help you lose weight. The story caught fire and spread around the world but the real experiment was to see if a weak study with obvious flaws could be published and grab media attention. The lead author of the study revealed after the fact:
“I am Johannes Bohannon, Ph.D. Well, actually my name is John, and I’m a journalist. I do have a Ph.D., but it’s in the molecular biology of bacteria, not humans. The Institute of Diet and Health? That’s nothing more than a website.
Other than those fibs, the study was 100 percent authentic. My colleagues and I recruited actual human subjects in Germany. We ran an actual clinical trial, with subjects randomly assigned to different diet regimes. And the statistically significant benefits of chocolate that we reported are based on the actual data. It was, in fact, a fairly typical study for the field of diet research. Which is to say: It was terrible science. The results are meaningless, and the health claims that the media blasted out to millions of people around the world are utterly unfounded.”
So it’s no wonder that the public gets confused about real science and fake science. The media does the public a great disservice by this type of reporting, but let’s be honest: “Overturns all previous theories” is going to sell better than: “Incremental advancement to a large body of prior knowledge”, as Dennis points out.
Dennis then covers the “two books” understanding; the view that nature and Scripture are each books authored by God. All truth is God’s truth. It’s His creation, His universe; therefore whatever we discover to be true must, by foundational presupposition, be His truth. God is revealed in his creation. Psalm 19:1 declares: “The heavens declare the glory of God; and the firmament sheweth his handiwork.” Romans 1:20 tells us: “For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead…” This is often called “General Revelation.” God is revealed to us in the Bible, His Special Revelation. John 5:39 says: “Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me.” Therefore, between God’s General Revelation (nature) and His Special Revelation (the Bible) there must be perfect harmony.
The study of God’s general revelation is what we call science. The study of God’s special revelation is what we call theology. But because of epistemological and hermeneutical limitations we have neither perfect understanding of nature nor perfect understanding of the Bible. Hence conflict is not only to be expected, it is inevitable.
Dennis then recounts the Galileo/Copernicus geocentric vs. heliocentric controversy. The basic issues that were on the table for them are the same as they are now; the truth of the new science versus it’s perceived threat to the authority of the Bible. He gives a long quote by Jonathon Edwards who held that when science and scripture are in tension, the science must give way to the Bible because it is the “higher authority”. But then Edwards gives a scientific argument that since we can feel earthquakes we ought to be able to “feel” if the earth is moving around the sun. Edwards quote:
“Nay, truly, if the earth were hurl’d about in a Circle (as these persons assert) we should feel it to our sorrows, for we should not be able to keep our ground, but must necessarily be thrown off, and all Houses and other Buildings would be thrown down, being forcibly shake off from the Circumference of the Earth, as things that are laid on a Wheel are flung off by it when it turns around.”
And one of the key predictions of heliocentrism is stellar parallax. If the earth circles the sun once a year then as its position in space shifts, we should observe shifts in how the stars are positioned relative to one another.
As Edwards was aware, the hypothesis made a prediction, the prediction could not be verified, the hypothesis was therefore falsified. Except… in the 1600’s what was unknown was just how far the stars were from the earth.
Then in 1838 Friedrich Bessel made the first successful parallax measurement ever, for the star 61 Cygni, using a Fraunhofer heliometer at Königsberg Observatory.
Now, scientists failed to reject the hypothesis and heliocentrism was held to be the best explanation of the facts. As Dennis says:
“In the 1600’s, pretty much all Christians were geocentrists, with only rare exceptions. From the 1900’s through to the present day, the situation is reversed (yes, there are still Christian geocentrists out there, though they are extremely few in number). The shift, then, was a gradual one, with plenty of opportunity for gradual theological change within the church along the way. And what of Edward’s strong assertion that if heliocentrism is true, then Scripture is false? Well, it seems that few believers see it that way today.”
Dennis then deals with tetrapod (four footed) evolution. If one goes back in the fossil record there was a time when no tetrapods existed, only abundant fish. Evolutionary biology predicts, counterintuitively, that tetrapods are descendants of fish. Fish are aquatic, have gills, and lack limbs. Tetrapods breathe air, have limbs, and are generally terrestrial.
Yet there are lines of evidence that seem to force the biologist’s hand. All tetrapods, like fish, are vertebrates (have a backbone). There are no invertebrate tetrapods. When amphibians first appear in the fossil record they bear resemblance to the lobe-finned lungfish (that persist to this day). Lungfish have both gills and an air sac to breathe with and they have fleshy limbs and bones within their fins. As we move forward in the fossil record the animals we find appear more amphibian like and less fish like.
Have we proved that fish evolved into amphibians? No, but we have failed to reject the hypothesis that early amphibians share a common ancestor with lungfish.
Dennis then uses as his second example, another counterintuitive prediction that some tetrapods, after having adapted to a terrestrial environment, nonetheless returned to the sea i.e. whale evolution.
Did critics find this ridiculous? Of course they did. Consider this quote from Robert B. Seeley:
“Thus Mr. Darwin, while he finds it impossible to believe the plain words of Moses that on the fifth day, “God created whales”—“sees no difficulty” in believing that a race of bears, by contracting the habit of swimming, gradually lost their legs, and were “developed” into whales of a hundred times their own bulk! And this sort of trash is called “science”! … Let us look, for a moment, at this whale, or bear, or bear-whale. What says Geological Science to it? Geology replies that she finds bears in the crust of the earth, and many of them; and that she also finds whales. But that the whale-bear, or creature which was developing from a bear into a whale, she never met with. And, not finding it, she no more believes in it than in a phoenix or roc. In a word, Geology, which is really a science, declares Mr. Darwin’s bear-whale to be a rank imposter.”
And this charge is still made today by creationists: there are no transitional fossils. But one characteristic of the modern cetacean skull is a distinctive thickened portion covering the middle ear, a structure known as the involucrum. This characteristic feature, thought only to occur in cetaceans, was found in a small hoofed mammal, Indohyus, an extinct species that lived in India 48 million years ago. Indohyus belongs to a group of mammals know as artiodactyls or “even-toed” hoofed mammals, of which species like deer, cows, and hippos are modern day examples. Curiously, Indohyus had features consistent with semi-aquatic lifestyle, like thicker bones for ballast like hippos. Another feature of artiodactyls is a particular ankle bone, the astragalus. A second group of artiodactyls from the same region, the Pakicetids have the astragalus and the involucrum and heavy thick bones. Relatives of the Pakicetids, the Ambulocetids, also come from this region, except these artiodactyls were semi-aquatic marine predators. They probably would have looked like giant otters.
Later in the fossil record we find Protocetids that have skeletal features indicative of a more fully aquatic lifestyle. The nostrils in Protocetids are not at the tip of the snout but are shifted back along the skull, and the hind limbs appear not to be able to bear the full weight of the mammal, much like a modern sea lion. And so on. Do we know for certainty that these creatures are ancestors of whales? No, it all could be a series of remarkable coincidences. But again, given this fossil evidence, we have again failed to reject the hypothesis that whales, dolphins, and porpoises descend from terrestrial tetrapod ancestors. Dennis ends this chapter with:
“It’s common for people, upon seeing such evidence for the first time, to begin to reflect on the immense probability of such large changes taking place repeatedly within a lineage. How could a mutation so large occur to change one animal from one form to another without killing it? How would such an animal breed with anything, unless these rare, massive mutations just happened to occur with a male and female in the same generation? Isn’t this all wildly improbable?
Well, yes, such a process would be wildly improbable—so improbable, in fact, that no scientist thinks it could ever happen. This does not pose a problem for evolution, however, because this is not how evolution works. How it does, in fact, work is the topic we will turn to next.”