Is Homo floresiensis a Legitimate Human “Hobbit” Species?

Did the diminutive skull (LB1) found a decade ago in Liang Bua Cave belong to a previously unrecognized human species called Homo floresiensis? Perhaps not. LB1’s owner may simply have had Down syndrome. Since its discovery on the Indonesian island of Flores with a short thigh bone, other skeletal fragments, and bits of an elephant barbecue complete with cooking tools, Homo floresiensis has occupied an oft-debated place on the evolutionary roster of archaic human species.

Common Things Occur Commonly

Young medical students are famous for seeing striped unicorns where their mature mentors see horses, but they must learn: common things occur commonly. Could the same be said for the discoverers of the little person in Liang Bua Cave on Flores? Have anthropologists created a whole new species of archaic human—hailed as “the most important find in human evolution for 100 years”—to explain a person with Down syndrome living in a cave with his or her fellow humans?

Down syndrome occurs commonly. At about 1 in every 700 births and usually caused by an extra copy of chromosome 21, Down syndrome is the most common genetic disorder.1 New studies make an excellent case that evolutionary anthropologists have been overzealous in their insistence that a Lilliputian human species lived on Flores. If that is true, then evolutionary anthropologists should remove the name Homo floresiensis from their list of archaic human species.

Human Evolutionary Anthropological Bandwagon

LB1 was likely just an ordinary South Sea islander with Down syndrome according to an international research team whose work was recently published in Proceedings of the National Academy of Sciences. The hub-bub over the validity of Homo floresiensis as a species highlights “paleoanthropology’s idiosyncrasies”2 and illustrates “a ‘bandwagon effect’ in human ancestry reconstruction, among professionals and journalists,”2 say the authors, who have been called irrational for their position.

Dr. Robert Eckhardt, coauthor and Penn State professor of developmental genetics and evolutionary morphology, notes his team was denied access to the bones after questioning the legitimacy of considering them a new species. He writes, “Questioning majority view is [called] ‘irrational,’ imposing a penalty with that label, while joining the majority carries easier access to funding and publication, as for ‘Homo floresiensis’ advocates.”2

Eckhardt and Maciej Henneberg, professor of anthropology and comparative anatomy at the University of Adelaide Medical School, sum up their unpopular assessment of LB1 in contradistinction to the majority view:

Many supposedly “unique” features of LB1 (short stature, low humeral torsion) are shared with other extant humans; others (mandibles lacking external chins, rotated premolar teeth) are common in Flores Rampasasa among extant Australomelanesians, while LB1’s tiny brain, marked asymmetry, and unusually short femora signal developmental abnormality.

Our hypothesis, offered in 2006, remains constant: LB1 is an abnormal individual from a relatively recent Flores population. Contradictorily, supporters of “H. floresiensis” originally held that it evolved from H. erectus isolated on Flores over more than 800,000 years, then switched in 2007 to attribute its small brain and short stature to African ancestors a million years before reaching Flores.2

Commenting on their present conclusions, Eckhardt indicates a simpler explanation is in order:

This work is not presented in the form of a fanciful story, but to test a hypothesis: Are the skeletons from Liang Bua cave sufficiently unusual to require invention of a new human species?

Our reanalysis shows that they are not. The less strained explanation is a developmental disorder. Here the signs point rather clearly to Down syndrome, which occurs in more than one per thousand human births around the world.

Which Disorder?

The possibility that Homo floresiensis—a species designation based on the single skull (LB1, or Liang Bua 1) and thigh bone—was an ordinary human with a microcephalic disorder has been raised before. Those who discovered and named the cave “creature”3 and believe it must be a unique human species have rebutted those claims. LB1’s astonishingly small cranial capacity was initially estimated as 380 cc, less than 1/3 the norm for modern adult humans. Later measurements, while small, have consistently been significantly larger.

Some researchers have maintained that the proportions of the cranial measurements in LB1 don’t match those of extant microcephalic people. Others have pointed out that the extant microcephalics chosen for comparison were children, not adults. And so the debate has raged on. Eckhardt’s team has re-examined the data on LB1, including some previously unpublished measurements. Their findings confirm that LB1 was an ordinary human who most likely suffered from Down syndrome, a very common birth defect.

Down Syndrome

Down syndrome, also called trisomy 21, is the most common human congenital chromosome abnormality. People with Down syndrome usually have an extra copy of the 21st chromosome. They are often mildly mentally retarded and have a suite of physical characteristics usually including a characteristically broad face with short stature. About 40% have congenital heart disease, and any of about 80 other traits may also be present, most of which would not be detectable from skeletal remains.

So what exactly did Eckhardt’s team discover to support their diagnosis of Down syndrome? By factoring in a previously unpublished measurement of the unfossilized skull—the “occipitofrontal circumference” measured just above the ears—as well as the higher cranial capacity of 430 cc repeatedly confirmed by investigators since the original very low estimate, Eckhardt’s team confirmed their original suspicion that an ordinary human developmental abnormality was the solution to the paleo-puzzle on Flores.

“When we first saw these bones, several of us immediately spotted a developmental disturbance," Eckhardt explains, “but we did not assign a specific diagnosis because the bones were so fragmentary. Over the years, several lines of evidence have converged on Down syndrome.”

LB1 exhibits craniofacial asymmetry, a common finding among people with Down syndrome. At first dismissed by some as an artifact of being buried, the marked facial asymmetry included a twisted palate, and asymmetrical tooth wear confirmed that the asymmetry affected the skull’s owner in life.4

Cranial capacity is not generally measured in living humans, but the occipitofrontal circumference is. Comparison of this measurement from LB1 with data available on Australomelanesian patients with Down syndrome demonstrates that LB1’s small head is consistent with the degree of microcephaly occurring among Australomelanesians with Down syndrome.

The controversy over whether to classify them as yet another twig on humanity’s evolutionary tree is rightly called a “paleontological idiosyncrasy” by Eckhardt, himself an evolutionist. But this idiosyncrasy is a symptom of a deeper one.

The original “barely 3 feet tall”5 reported for LB1 was derived from the length of the femur using a model proportioned for African pygmy populations. This estimate was also erroneously low, Eckhardt’s team maintains. Growth models for Australomelanesians do not match those of African pygmy populations. And growth abnormalities associated with Down syndrome affect some long bones more than others, producing disproportionately short thigh bones. The femur length—when used to recalculate the height of a Down syndrome owner in combination with data from other bones in the cave and plugged into a geographically consistent Australomelanesian model—produces a height of just over 4 feet. This height is in the lower normal range for some Australomelanesian populations. Eckhardt and Henneberg conclude that LB1 was part of “a small-bodied Australomelanesian population”5 and had Down syndrome.

All in the Family

Eckhardt and Henneberg point out also that the allegedly primitive features found on LB1 do not fit any human or hominin species known to archaeologists. These “primitive” traits are not primitive at all when considered in the context of modern humans with developmental abnormalities. This has nothing to do with evolution.

The occupants of Flores island, memorialized by a few unfossilized remains in Liang Bua Cave, were clearly human, as we have always maintained. The controversy over whether to classify them as yet another twig on humanity’s evolutionary tree is rightly called a “paleontological idiosyncrasy” by Eckhardt, himself an evolutionist. But this idiosyncrasy is a symptom of a deeper one.

Because of their denial of the historical documentation of human origins in the Bible, evolutionists assume that human beings evolved from ape-like ancestors and try to trace their lineages across eons of time and the globe. Humans are all descendants of Adam and Eve and were created about 6,000 years ago in the image of our Creator, God. We are thus distinct from animals and are not the products of any evolutionary process.

The population bottleneck of the global Flood reduced the human population to the eight people on the Ark, and from their descendants the world was repopulated. After humanity’s dispersion from the Tower of Babel, it is not surprising that a number of groups became isolated and developed unique physical characteristics. But all were human. To insist that some varieties of humans have belonged to separate evolutionary lineages is not an exercise in observational science but a worldview-based construct. Thus this insistence on dividing human beings into separate evolutionary lineages is not just paleontological idiosyncrasy but an evolutionary fairy tale.

Read more about “cavemen”—a common term applied to varieties of people who lived during the Ice Age—in the context of biblical history in “Were Cavemen Real?,” “When Did Cavemen Live?,” and “Neanderthals vs. Humans: Are They Different?”