Human Evolutionary Lineages Teeter on Neanderthal-Style Inner Ear

by Dr. Elizabeth Mitchell on August 21, 2014

Neanderthal labyrinth in non-Neanderthal fossil hints at maze of post-Babel migrations.

Huffington Post: Ancient Skull Reveals Human Ancestors Had Odd Neanderthal-Like Inner Ear

How can you tell a fossilized skull belonged to a Neanderthal? The comparatively large size and prominent brow ridges? Actually—until now at least—paleoanthropologists have looked at a more subtle feature: the shape of the labyrinth in the inner ear. This bony chamber cradles the human body’s balance organ—the semicircular canals—within the temporal bones on each side of the skull. The Neanderthal bony labyrinth differs from that of modern humans and other archaic humans in a suite of subtle but specific ways long deemed diagnostic of Neanderthals. But not anymore!

canalsThese two views from an educational YouTube video show the semicircular canals. The three fluid-filled semicircular canals are about 1.5 mm in diameter. They are arranged at right angles to one another. The anterior one is closest to the spiral-shaped cochlea, which conducts sound to the brain. Together these semicircular canals detect rotation and help maintain balance. Images: Dr. Robert Droual, Modesto Junior College, Bony Labyrinth Model: Semicircular Canals on YouTube

This discovery has shown some evolutionary anthropologists that their view of human lineages and migratory patterns is oversimplified. According to Washington University paleoanthropologist Erik Trinkhaus, the truth about human relationships and historical geography is much more of a labyrinth than evolutionary anthropologists have imagined.

The bony home of the inner ear in Xujiayao 15, an archaic human’s skull recovered 35 years ago in East Asia, matches that of Neanderthals, but Xujiayao 15 was not Neanderthal. “We were very surprised,” Trinkaus says, because “it looks like a Neanderthal,’” adding, “It's clearly not modern human.” The bony labyrinths of other archaic humans more nearly resemble those of modern humans. “We fully expected the [CT] scan to reveal a temporal labyrinth that looked much like a modern human one,” Trinkhaus says, “but what we saw was clearly typical of a Neanderthal.”

Inner Story

Your inner ear consists of the spiral-shaped cochlea—which transmits sound to your brain—and three semicircular canals (plus a saccule and utricle) for balance—sort of a biological gyroscope. The semicircular canals—each roughly 2/3 of a circle and about 1.5 mm in diameter—are oriented in three dimensions at right angles to each other. The shifting of fluid within them pushes against sensory structures to detect changes in angular momentum (rotation). These semicircular canals are part of the bony labyrinth embedded within the petrous portion (“stone” bone) of the skull’s temporal bone. Therefore the shape of the semicircular canals is often preserved in a fossilized skull. High-resolution CT scans can measure these canals and map their relative positions.

canals skullsThe semicircular canals fill the bony labyrinth in the inner ear. The bony labyrinth is within the petrous part of the temporal bone. The temporal bone of Xujiayo 15 is pictured in the top photos. The lower illustration shows the position of the bony labyrinth, and on the right is the bony labyrinth’s CT-based reconstruction. In Neanderthals—and in Xujiayao 15 shown here—the anterior canal is slightly smaller, the lateral canal slightly larger, and the posterior superior canal is placed just a little more inferior relative to the lateral canal than in most modern and other archaic humans. Image: Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Science through Huffington Post

Neanderthal semicircular canals have characteristic proportions and positions that subtly differ from those in most other archaic humans and modern humans.1 Paleoanthropologists have long considered the characteristic Neanderthal semicircular canals to be diagnostic—a reliable litmus test to identify a skull as Neanderthal.2

Evolutionary Implications?

So what does Trinkhaus think about this discovery’s implications? He remains cautious and says that for now the implications are unclear:

The study of human evolution has always been messy, and these findings just make it all the messier. It shows that human populations in the real world don't act in nice simple patterns. . . . It suggests, instead, that the later phases of human evolution were more of a labyrinth of biology and peoples than simple lines on maps would suggest.”3

Over are the days of assuming that this semicircular canal configuration is a defining characteristic of a Neanderthal, Trinkhaus makes clear:

You can't rely on one anatomical feature or one piece of DNA as the basis for sweeping assumptions about the migrations of hominid species from one place to another. What these findings say to me are that characteristics were probably more varied in ancient human populations than we think. We see characteristics mix and match in populations across the world nowadays, and I believe that characteristics shuffled back and forth in ancient human populations across the landscape over centuries and millennia. The idea of distinct, separate lineages in this time period in human evolution is meaningless—it was much more of a labyrinth than that.

Babel of Traits

Following the global Flood and dispersal from the Tower of Babel, the descendants of Noah’s family dispersed. Some isolated groups of people would have developed distinguishing traits, but all were still human. That there is overlap of some of these features is no surprise, as all these people were descended from Noah’s sons and their wives. And though people emigrated away from the Tower of Babel, intermarriage between groups would be no surprise, and thus the sporadic occurrence of traits not normally associated with certain groups would be expected.

Learn more about the labyrinthine dispersal of people and what we can learn about their descendants that dispersed through the world from the plains of Shinar in “Was the Dispersion at Babel a Real Event?” Biblical history makes sense of the maze of migrations, which have nothing at all to do with human evolution. Neanderthals and other archaic humans were just as human as the person each of you sees in the mirror.

For more information:

  • Piecing Together Neanderthals at Sima de los Huesos
  • Sima de los Huesos Reveals Surprising Genetic Connections
  • Vegetables for Neanderthals
  • Neanderthal Toe Said to Suggest an Incestuous Culture
  • Does the Creation Model Make Predictions? Absolutely!
  • How Are Cavemen Different?
  • Who Were Cavemen?
  • For more information: Get Answers

    Remember, if you see a news story that might merit some attention, let us know about it! (note: if the story originates from the Associated Press, FOX News, MSNBC, the New York Times, or another major national media outlet, we will most likely have already heard about it.) And thanks to all of our readers who have submitted great news tips to us. If you didn’t catch all the latest News to Know, why not take a look to see what you’ve missed?

    (Please note that links will take you directly to the source. Answers in Genesis is not responsible for content on the websites to which we refer. For more information, please see our Privacy Policy.)


    1. There actually is overlap in some aspects of the labyrinthine shape in Neanderthals with that of European Middle Pleistocene people. The entire suite of characteristics, however, has been in the words of University College London paleontologist Fred Spoor and colleagues “among the most diagnostic parts of the Neanderthal skull.” In their definitive 2003 Journal of Human Evolution paper discussing it and proposing some functional significance (see footnote #2) they wrote: “Compared with Holocene humans the bony labyrinth of Neanderthals can be characterized by an anterior semicircular canal arc which is smaller in absolute and relative size, is relatively narrow, and shows more torsion. The posterior semicircular canal arc is smaller in absolute and relative size as well, it is more circular in shape, and is positioned more inferiorly relative to the lateral canal plane. The lateral semicircular canal arc is absolutely and relatively larger. Finally, the Neanderthal ampullar line is more vertically inclined relative to the planar orientation of the lateral canal. The European Upper Palaeolithic and early modern humans are most similar, although not fully identical to Holocene humans in labyrinthine morphology. The European Middle Pleistocene hominins show the typical semicircular canal morphology of Neanderthals, with the exception of the arc shape and inferiorly position of the posterior canal and the strongly inclined ampullar line. The marked difference between the labyrinths of Neanderthals and modern humans can be used to assess the phylogenetic affinities of fragmentary temporal bone fossils.” (From F. Spoor et al., “The bony labyrinth of Neanderthals,” Journal of Human Evolution 44 (2003): 141–165, doi:10.1016/S0047-2484(02)00166-5.)
    2. Spoor maintains that, because more agile mammals tend to have larger semicircular canals (when adjusted for body mass), Neanderthals were less agile than other archaic and modern humans. This may or may not have been the case, but Spoor’s conjecture is based on evolutionary assumptions; furthermore, if a particular ethnic group possesses more or less of a physical attribute, there is nothing about that distinction that supports molecules-to-man evolution.


    Get the latest answers emailed to you or sign up for our free print newsletter.

    See All Lists

    Answers in Genesis is an apologetics ministry, dedicated to helping Christians defend their faith and proclaim the gospel of Jesus Christ.

    Learn more

    • Customer Service 800.778.3390