800 kyr old human development pattern

Glenn R. Morton (grmorton@waymark.net)
Sat, 10 Apr 1999 12:32:15 -0500

Last week I rain into an article on the web that confirms once again
what I have been saying for the past few years, namely, that humanity
has been on this planet for at least 2.5 myr and probably longer. This
article is consistent with the evidence that Homo rudolfensis and Homo
erectus had a human, not ape, pattern of birth and development as long
ago as 2.5 myr.
(see http://www.calvin.edu/archive/evolution/199806/0242.html



Thus I disagree with Bromage's statement below--see G.R. Morton "Dating
Adam," PSCF June 1998 in press).

The widely popular view among Christians that humanity suddenly appeared
within the past 100,000 years has been falsified so many times that one
must wonder why Christian apologists don't do a better job of keeping
the laity and themselves informed of the latest developments in the
fields they claim expertise. I will document another sad case in another

Christian apologists, unfortunately, have had a centuries long tradition
of ignoring the latest findings and never allowing observational data to
alter one's theological position. This, to me, is merely hiding one's
head in the sand. One gentleman I was having a conversation with last
week, claimed that he had to merely watch anthro from an outsider's
position and thus didn't feel comfortable making judgments about data
with which he was personally unfamiliar. If any reader feels this way,
then I would ask, Do you believe that God holds the unbeliever
accountable for the spiritual light they are told about and yet reject?
If so, why does God not equally hold us Christians accountable for
dealing with the scientific knowledge we are shown regardless of whether
or not it is within the confines of our field of expertise or regardless
of whether it supports or contradicts our theological position? To
ignore data simply because it is outside of our field of expertise is
not the honest thing to do.

Christians and christian apologists simply must begin to deal with data
that contradicts their preferred theological position. Here is the

The Weekly Newsmagazine of Science

Volume 155, Number 14 (April 3, 1999)

Human Growth Displays Ancient Roots

By B. Bower

Three unfortunate youths who died about 800,000 years ago have provided
a hint that the prolonged period of childhood growth and development in
humans has surprisingly old origins.

This form of delayed maturation, accompanied by protracted child care
and a complex social life, is often regarded as a hallmark of modern
humans. However, the ancient youngsters, who may belong to a species
that preceded Homo sapiens, exhibit a tooth-development pattern similar
to that of people today, contends a research team led by paleobiologist
José M. Bermúdez de Castro of the National Museum of Natural Sciences in

"This evidence supports the view that as early as [800,000 years ago],
at least one Homo species shared with modern humans a prolonged pattern
of maturation," the researchers report in the March 30 Proceedings of
the National Academy of Sciences.

Bermúdez de Castro and his team found the fossils in a cave in northern
Spain's Atapuerca Mountains. They assign the specimens to a new species,
Homo antecessor, although other investigators go no further than placing
them in the Homo line (SN: 5/31/97, p. 333).

For each fossil individual, the scientists noted the relative maturity
of pairs of teeth from the front and back of the mouth. The team then
compared these data with dental measures obtained by other researchers
for living apes and humans, as well as for older fossils in the human
evolutionary family.

Only the Spanish fossils exhibited a pattern of dental development much
like that of modern humans, with relatively late eruption of many teeth,
the investigators say. The third molar in the Atapuerca specimens
reached maturity sooner than in current European populations, although
the timing of its appearance lies within the worldwide human range,

Analyses did not allow for precise chronological age estimates for the
three fossil individuals. Two died in early adolescence and one as a
young child, according to the researchers. One of the adolescents
exhibited a tooth deformation caused by a severe childhood growth

Humanlike dental development in the Atapuerca fossils renders more
plausible an earlier report that they had brain-case volumes nearly as
large as those of modern H. sapiens, Bermúdez de Castro and his
coworkers hold. The Spanish scientists had estimated this volume from a
cranial fragment believed to have come from one of the fossil teenagers.

"There's still some primitiveness in these teeth, but they also show the
delayed system of maturation seen in modern humans," comments
anthropologist F. Clark Howell of the University of California,
Berkeley. "The Atapuerca individuals seem to have crossed some kind of
growth-related Rubicon."

The new study provides "the first substantive evidence" for extended
individual development before the emergence of H. sapiens, adds
anthropologist Tim Bromage of Hunter College in New York City.
Intriguingly, major abnormalities from the growth disturbance that
afflicted one of the Atapuerca youngsters likely required the child to
receive extensive care from adults, in Bromage's view. "I find something
human in that," he remarks.

Neandertals, which lived from about 135,000 to 30,000 years ago, also
exhibited a modern human life-history pattern, presumably retained from
ancestors such as those at Atapuerca, Bromage says.

If the new findings indeed come from an earlier Homo species, they
challenge the assumption that prolonged individual development can serve
as a distinguishing trait of modern humanity, the New York researcher

Much remains unknown about the pattern and rate of growth in ancient
human ancestors, according to Howell. Other Atapuerca remains, which
date to 300,000 years ago and belong to a Neandertal-like species (SN:
4/10/93, p. 228), include juvenile specimens that the researchers now
can subject to dental analyses, he says.


Bermúdez de Castro, J.M., et al. 1999. A modern human pattern of dental
development in Lower
Pleistocene hominids from Atapuerca-TD6 (Spain). Proceedings of the
National Academy of Sciences
96(March 30):4210.

Further Readings:

Bower, B. 1997. Spanish fossils enter human ancestry fray. Science News
151(May 31):333.

______. 1993. Neandertals take big step back in time. Science News
143(April 10):228.


José M. Bermúdez de Castro
Musco Nacional de Ciencias Naturales
Departamento de Paleobiología
Consejo Superior de Investigaciones Científicas
J. Guitiérrez Abascal 2
28006 Madrid

1999, Science Service.