February 2022, ScientificAmerican.com 55cause they are filled with cave sediment that buried the bone and
are covered with lacquer, which paleontologists used to apply to
fossils to preserve them. All these factors strongly suggest that a
Neandertal made the marks.
Researchers have observed linear marks on bones at a few other
Nean der tal sites, but so far these cases involve only limb bones
from animals found at these locales. The marks on the Krapina 3
Neandertal skull deviate from all the other examples of bone mod-
ification at the site and are unique in the fossil record. They prob-
ably signify some kind of ritual behavior, whether ceremonial mod-
ification of the remains of a loved one, numerical recording or doo-
dling. Whatever the exact symbolic significance of these cut marks,
the eagle talons or the starry stone, Neandertals were ascribing
meaning to them 130,000 years ago—90,000 years before modern
humans reached Croatia.RIGHTIES AND LEFTIES
aNoTher syMbolic behavior —one that scholars have often held up
as a defining characteristic of modern humans and the secret of
our success as a species—is language. Did Neandertals have lan-
guage? Did they gossip about their neighbors, talk about their
hopes and fears, tell their children bedtime stories? Without a time
machine to transport us back to their era, we cannot know for cer-
tain. But there are hints in the archaeological and fossil records. A
number of archaeologists consider body ornaments and other phys-
ical manifestations of symbolism to be proxies for language.
Neandertal fossils themselves also contain clues.
We set out to determine whether Neandertals preferentially
used one hand over the other in their daily tasks. Right-handed-
ness is a common human trait; right-handers dominate left-hand-
ers in every living human population. Handedness reflects the fact
that the two hemispheres of the brain are asymmetrical, with each
side specialized for different tasks. This brain lateralization, as it
is termed, is associated with language capacity. Other primates ex-
hibit varying degrees of lateralization, but only humans show such
a high frequency of right-handedness.
To assess the handedness of the Krapina Neandertals, we used
optical and scanning electron microscopy to examine scratches in
the enamel of their incisor and canine teeth. These striations,
which occur exclusively on the lip side of the teeth, were produced
when a stone tool accidentally etched the enamel. This kind of
damage can occur when an individual uses his or her teeth as a
third hand of sorts to grip an object—for instance, an animal hide.
When a right-hander holds a tool and rakes it across material held
between the front teeth, as one might do to clean an animal hide,
any time the tool hits a tooth, it will leave a right-angled scratch
on the tooth. A left-hander leaves an oppositely angled scratch. By
studying the angles of the scratch marks evident in even a single
fossil tooth, we can determine whether it belonged to a right-
handed or left-handed individual.
Our analysis of the Krapina Neandertal teeth identified nine
right-handers and two left-handers. If we expand our sample to in-
clude Neandertals from other European sites, the ratio of right-
handers to left-handers replicates the typical 9:1 pattern of living
humans. Interestingly, this pronounced dominance of right-hand-
edness is not found first in Neandertals but extends back to their
European predecessors and an even earlier member of our genus,
Homo, from Africa. Apparently hemispheric brain asymmetry—
and thus perhaps language—is an ancient human trait.
Neandertals had more than just behavior in common with
modern humans. In-depth studies at Krapina and other sites show
that many morphological characteristics once thought to be
unique to Neandertals are found in moderns, and some modern
features are found in Neandertals. One such trait is the form of
an opening on the tongue side of the lower jaw (mandible) called
the mandibular foramen. The mandibular nerve passes through
this opening to innervate the teeth, gums and chin. In modern
humans, the upper portion of the foramen is commonly V-shaped.
In most Neandertals, the opening is covered by a bar of bone and
is called a horizontal-oval (H-O) foramen. But at Krapina, only
four of the nine Neandertal mandibles that preserve this part of
the bone have the typical Neandertal H-O foramen; five show the
modern V-shaped pattern.
Numerous other cranial and postcranial features in the Krapina
Neandertals overlap with early modern humans, too. No doubt
Neandertals had a distinctive morphology, but many of their traits
are also found much later in the modern people who followed them.
It is very unlikely moderns independently evolved these Neander-
tal-like traits. Rather there was probably a lot of variation in
Neandertal morphology, and in later times some interbreeding oc-
curred between them and our modern European ancestors. The
“unique” traits were passed on as part of these interbreeding events.
Given the apparent cognitive similarities between Neandertals and
early modern humans, we should perhaps not be surprised that
the two groups saw each other as humans and exchanged genes
when they encountered each other.
Despite the fact that excavations at Krapina were concluded
more than a century ago, the stones and bones from the site con-
tinue to provide new information about Neandertals and their
place in human evolution. Undoubtedly more secrets remain to be
revealed in the Krapina collection. We are endeavoring to tease out
some of them. For example, with colleagues from England and
Italy, we have been obtaining high-resolution, synchrotron images
of baby teeth from the site to evaluate growth rates as measured
by enamel formation. Modern humans are unique among living
primates in having an extended period of childhood growth, which
gives our large, powerful brains time to develop. Researchers have
debated just how similar Neandertal childhood development was
to that of moderns’. Our results show that Neandertal infants
formed their enamel a little faster than moderns, indicating a more
rapid growth rate on average. Yet it was still in the modern range.
Mounting evidence from sites across Europe is forcing scien-
tists to rethink their conception of these long-disparaged mem-
bers of the human family. The Krapina Neandertals are an im-
portant part of this shift. We suspect that future discoveries at
Krapina and beyond will further narrow the list of behavioral
and anatomical traits that supposedly set Neandertals apart from
moderns. They were not the same as us. But we have far more in
common with them than not.This article is dedicated to the memory of Jakov Radovˇcic ́, who served
as curator of the Krapina Neandertal Collection for 32 years.FROM OUR ARCHIVES
Neandertal Minds. Kate Wong; February 2015.
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