Hobbits Were Brain Diseased Modern Humans

The discovery of fossils of miniature humans in Indonesia, designated Homo floresiensis but nicknamed Hobbits, was one of the most exciting and controversial announcements of 2004.  Since then, interpretations of the fossils have fallen into two camps: those who think the skeletons represent normal humans with the brain-defective disease microcephaly (10/11/2006), and those who think they represent evolutionary missing links (10/25/2005).  A new paper compared skulls of H. floresiensis with those of modern humans, Homo erectus, and humans with microcephaly.  The result favors the interpretation that the Hobbits most likely were diseased modern humans.

The paper was published in PNAS today.¹  Using MRI, a team of three anthropologists from New York University and Columbia University measured craniometric ratios for 21 age-corrected skulls infants with microcephaly, with 118 normal skulls for control.  In addition, they measured skull bones of 10 microcephalic individuals, 79 anatomically modern humans, and 17 Homo erectus specimens.  These were compared with two skulls of the so-called Hobbits from Ling Bua cave 1 (LB1).  The results put pressure on those who maintain that the Hobbits represent an evolutionary transitional form prior to the emergence of modern humans:

The findings showed that the calculated cerebral/cerebellar ratios of the LB1 endocast [Falk D, et al. (2007) Proc Natl Acad Sci USA 104:2513–2518] fall outside the range of living normocephalic individuals. The ratios derived from two LB1 endocasts also fall largely outside the range of modern normal human and H. erectus endocasts and within the range of microcephalic endocasts. The findings support but do not prove the contention that LB1 represents a pathological microcephalic Homo sapiens rather than a new species, (i.e., H. floresiensis).

In another paleoanthropology article on PhysOrg, we learn that diet can play a big part in the shape of human fossils.  Researchers at Johns Hopkins found that “use over time and not just genetics informs the structure of jaw bones in human populations.”  It’s all about engineering: “The changes to the jaw bones were explained using a theory drawn from engineering, which directly relates the geometry of a bone to the stresses put on it during use.” 

While this announcement offers hope for inferring the diet of ancient people, it also casts doubt on phylogenetic interpretations.  “Mechanical pressure from muscle stress and strain from day-to-day activities can remodel the bone’s surface and internal structure,” said JHU anthropologist Megan Holmes.  “Knowing how much the shape of a mandible we find is related to diet and how much genetically connects it to fossils found elsewhere can really help us parse out the family tree” – provided information on probable diet is available, it would seem.

So can scientists conclude that “Big brains evolved due to the capacity for exercise?” as another article on PhysOrg suggested?  While the researchers did compare a lot of mammal skulls, it’s not clear that the evolutionary trend they suggested worked on wildebeests and Arctic terns.  Besides, maybe quality counts more than quantity (03/04/2005, 02/07/2010).  Today’s hand-held devices pack more power than the first PCs.  The article indicated that they have more work ahead to test their idea, but maybe not too much can be interpreted about the Hobbits without being able to test their IQ.

For earlier articles on Homo floresiensis, see 10/27/2004 for the original entry and search on “Hobbit” in the search bar for over a dozen more.

1. Vannucci, Barron, and Holloway, “Craniometric ratios of microcephaly and LB1, Homo floresiensis, using MRI and endocasts,” Proceedings of the National Academy of Sciences, published online before print August 8, 2011, doi: 10.1073/pnas.1105585108 PNAS August 8, 2011.

Don’t you just love scientific jargon?  Microcephaly means “small head.”  The word conveys no understanding whether in Latin or English; it is purely descriptive.  A farmer went to his doctor complaining that his butt itched.  The doctor got out his diagnostic manual, and announced to the patient that he had a case of rectal pruritus.  “What the heck is that?” the farmer asked.  “Itchy butt,” the doctor replied, scientifically.

Here’s a plausible scenario for the Hobbit skulls in the cave.  A few thousand years ago, a tribe of human pygmies (03/11/2008), small yet perfectly modern sons of Adam and daughters of Eve, had an epidemic of microcephaly among their members.  Worried they had displeased God, they buried the affected in a special cave, praying for mercy and dedicating the cave to their memory.  In 2004, evolutionists found these skeletons and shouted, “Missing links!”