Lucy—A Look at Evidence Quality for This “Evolutionary Icon”

Is human evolution true just because many “experts” keep shouting it’s true?

Is Broken Bone Evidence as Good as It’s “Cracked Up” to Be?

In November of 1974, Donald Johanson found the widely scattered and incomplete bone fragments that later became known as Lucy in the Olduvai Gorge, Tanzania, Africa. Johanson claimed that Lucy was a specimen of Australopithecus afarensis and a close ancestor of modern humans.1 Despite well-demonstrated objections to the evidence of Johansen and his followers, many people continue to virtually worship Lucy as a kind of goddess—or to venerate her as a sort of Eve, the mother of us all. How should creationists respond?

We need to argue about the bone bits, and this should include pointing out why the bone bits are poor quality evidence to begin with.

Creationists have been rightly pointing out evidence problems, including fragmentary skeletal remains,2 piecing together bones from over a wide area,3 and deliberate alteration of bones to promote the “transitional” illusion.4 However, we should also step back and consider larger issues in evidence quality. We need to argue about the bone bits, and this should include pointing out why the bone bits are poor quality evidence to begin with.

Is the Evidence a Few “Snapshots in Time” or a Full-Length Movie?

Good science is an extremely rigorous enterprise; that is to say, sound conclusions have to be based on plenty of evidence of the highest quality. We advocates of creation science must continually be evaluating the quality of our own evidence, as well as continually critiquing the quality of evolutionary evidence. Part of this critiquing process is comparing standards of evolutionary evidence to current standards of operational science. Of course, operational science is the experiment– and data–based science of the here and now. Let’s look at the evidence for Lucy in the light of current standards for the operational science of medicine.

As a medical doctor, being a reasonable judge of evidence quality was something I had to learn slowly over decades. This was because I entered medicine at a time when the field was dominated by expert–based truth claims. While learning the field, I did have exposure to evidence, but in areas of controversy, the final determination was what the expert said. (If there was more than one expert, the most aggressive or charismatic one usually won.) Learning to rely ultimately on evidence rather than experts was something that came to me slowly. Actually, I lived through a general transition from expert-based to evidence-based medicine. This whole social change in medicine—and some other branches of science and even law—is a long story, which I can’t go far into here. However, along my journey, I had several meaningful personal milestones. One typical example was finding out that the experts I trained under had been mistaken about the alleged evolution of melanocytic nevi.

So you are probably thinking, what are melanocytic nevi? You probably see at least several every day. All pigmentation of the skin of humans and many animals comes from melanin, a brown pigment that can be denser or sparser, producing many shades of brown. The melanin in turn is manufactured by specialized skin cells called melanocytes. Often the melanocytes grow abnormally to produce tumors in the skin. These are called nevi, or sometimes birthmarks. They are usually few, small, and benign (that means they are localized and don’t spread). Rarely, nevi may turn out to be malignant tumors, or melanomas, that can spread all over the body and cause death. Thus, many enlarging nevi get removed surgically to make sure they’re not melanomas. Microscopic examination of nevi by pathologists happens in this setting.

So what does this have to do with Lucy? Microscopy of melanocytic nevi probably seems out-of-the-way and boring (unless you are an anxious patient wanting a quick and accurate diagnosis for a large, changing skin nevus you have had a surgeon remove). Well, it was thought for many years that benign nevi went through a regular sequence of evolutionary change as they and their human host aged. I was taught this alleged evolutionary sequence. What was this evolutionary idea based on? Mainly on surgical excision of nevi followed by immediate, one-time microscopic examination. Large numbers on such cases were assembled in academic institutions as cumulative case studies. Thus, the evidence was a series of single, loosely related “snapshots in time” that seemed to show a pattern of evolution as the people with their nevi grew older. This idea was taught to me on good authority by the experts in the field. It appeared well-supported by evidence. That is, until a new generation of scientists came along with better tools and evidence and showed it was wrong.

It appeared well-supported by evidence. That is, until a new generation of scientists came along with better tools and evidence and showed it was wrong.

What happened was this. Dermatologists invented a diagnostic device called the “dermoscope” that could diagnose a nevus with reasonable accuracy without removing it. Thus, the natural history of each nevus could be followed over a period of years, instead of being examined only once in a frozen instant of time. This gave many more data points and allowed better assessment of cause-and-effect. This difference in research protocol shows the difference between “longitudinal” (following a subject through time) and “cross-sectional” (looking at only one instant in time) research study. The longitudinal approach is more time-consuming and expensive, but it yields more reliable results. In the case of nevi, it showed that some kinds of presumed evolution never happened at all, and other kinds happened but on a much more limited scale than was thought. For me, this was an up-close-and-personal demonstration that dedicated experts with lots of experience can be completely wrong if their supporting data is incomplete. Furthermore, it is like what has been discovered for other evolution examples as we study them more closely, such as the classic Darwin’s finches. The changes are small and show minor variation/adaptation within a biblical kind rather than big increases in genetic information such as Darwinism demands.

Judging Evidence

Getting back to medical science, expert-based medical truth claims were losing credibility years ago. They were slowly displaced by the idea of evidence-based medicine. It used objective criteria for judging evidence quality. Several systems emerged, which have these three main ideas in common:

• Grade A (best evidence): Prospective studies (following changes directly as they happen through time through detailed end-to-end study, like a full-length movie, also known as “longitudinal study,” as mentioned above)
• Grade B and C (second and third class): Cross-sectional studies, either with more evidence (many “snapshots in time”) or not much evidence, as in small group case reports (a few “snapshots in time”)
• Grade D (fourth class evidence or even lower): Opinions of respected authorities

It’s immediately obvious that evolution from anything like Lucy to us is far from a full-length movie or best-quality Grade A evidence. Neither is it many good snapshots in time. A hundred or so intact, well-preserved, fully articulated skeletons would be many good snapshots in time or Grade B evidence. But we don’t have that, as we shall see. What we have is a very few snapshots in time, and even those are blurry and incomplete. They are so incomplete we don’t even know just how many we have. Yet they are presented to us as facts to build our lives and our culture upon. They are affirmed by a small community of experts as showing we evolved from apelike ancestors like Lucy. Our education and media train us to regard these experts as authoritative.

But what does an evidence-based view do to this picture? Notice that an operational-evidence-based system turns upside down the evolutionary truth claims we have been accustomed to. They are like an upside-down pyramid with scant evidence of poor quality at the bottom, trying to support broad and huge truth claims made by experts at the top. We are constantly exhorted to believe the truth claims of expert secular geologists and paleontologists and ridiculed if we dispute them. But if we use an evidence-judging mindset like that of evidence-based medicine, the upside-down imaginary world of evolution is discarded, and we can properly base good conclusions on good evidence. Note that we should not do as they do, ridiculing those who disagree with us. In line with Scripture, we should respect authority, although we should also feel free to disagree publicly with it when it conflicts with Scripture and high-quality scientific evidence.

It may be objected that evidence-based medicine criteria have nothing to do with historical science practices and shouldn’t be used to judge paleontologists and geologists. The answer is that those historical sciences have huge gaps in their evidence bases and have gotten away with overstating their conclusions for far too long. Using good operational science standards exposes the weaknesses of these sweeping conclusions based on inadequate evidence. Besides, we expect high standards of evidence for medical treatments that affect our physical health. Shouldn’t we also expect similar high standards for science affecting our eternal spiritual health? Unless, of course, bad science has already convinced us that we don’t need to worry about our eternal spiritual well-being.5

In the case of Lucy and the implications of her myth, Sanford and Rupe have shown graphically just how inadequate the evidence base is. In a single picture showing the 300+ mostly tiny bone fragments designated as A. afarensis from the formative expeditions of the 1970s, the amazing lack of clear evidence is demonstrated.6 Even secular paleoanthropologists are deeply divided about interpreting these few bone bits, with some still maintaining that the bones are a mixture of at least two species or even genera. The idea that these few broken and mixed bone bits are good reason to take away our heritage of being created in God’s image is worse than tragic. Unscrupulous and pathetic are two other words that come to mind. Sadly, the murky depths of this bad science are hidden from the public. Rather than show truth, exhibits such as the Smithsonian’s and the St. Louis Zoo’s Lucy models portray fanciful, unscientific artwork as scientific fact.

Conclusion

In conclusion, the principles we should promote in assessing the very questionable evidence for Lucy may be extended to all areas of historical science. Above all, we should clearly recognize (and teach) that static evidence items in the present, with no demonstrable connection with alleged past events, can never be considered Grade A evidence. If old bones showed complete skeletons with clear transition to modern forms with new body plans, that might be considered Grade B evidence. But they never do. They show evolution so badly that they often need to be falsified. They are Grade C evidence or worse—not good evidence at all. Thus, they cannot prove anything beyond reasonable doubt. They should be considered legally and scientifically insufficient for depriving anyone of the Christian hope of eternal life.

Jeremiah brought God’s indictment against the idol worshippers of Judah saying, “The house of Israel shall be shamed: they . . . who say to a tree, ‘You are my father,’ and to a stone, ‘You gave me birth’” (Jeremiah 2:26–27). Today we may say, “They shall be shamed: they who say, ‘You are my mother’ to scattered bits of dry bones.” The evolutionary goal of trying to prove we evolved from apelike ancestors is revealed as a revival of pagan idolatry. No more and no less. Christians—or anyone for that matter—need not be intimidated at all by old bone bits thrown at us as “proof” that we were not created in God’s image.