Science delves into Neanderthal weaning habits

Science delves into Neanderthal
weaning habits



Neanderthals may have started weaning their young
from seven months of age and transferred them to solid food by just over a year,
a fossil tooth study said Wednesday.

This is within the range for modern
humans and chimpanzees, a research team wrote in the journal Nature, but may
have been later compared to Stone Age Homo sapiens.

Data does not exist
for the age at which humans from that period weaned their children, but some
scientists hypothesise it would have been at a younger age than
Neanderthals.

Shorter breast-feeding would have meant quicker intervals
between children and more rapid population expansion for humans.

An
enigmatic branch of the human family tree, Neanderthals lived in parts of
Europe, Central Asia and Middle East for up to 300,000 years but vanished from
the fossil record about 30-40,000 years ago.

Why they disappeared is one
of the hottest topics in anthropology. Theories say they may have been victims
of climate change or were massacred by their H. sapiens cousins -- some also
advance the later weaning scenario.

For the study, an international team
of scientists developed a radar technique to read levels of barium, a chemical
element in milk, in tooth enamel -- almost like the growth rings of
trees.

They compared readings from a juvenile Neanderthal fossil tooth
with those from modern human and macaques teeth.

Barium levels in teeth
have in other research been shown to be higher during breastfeeding in human
children, dropping during weaning, and then again after the conversion to solid
food.

The mineralisation of barium in human tooth enamel already starts
in the second trimester of pregnancy, when the immature teeth are still in the
jawbone.

The study noted that humans may completely wean their offspring
from the age of one year without serious health effects, but generally do so
around an average 2.3 to 2.6 years.

For chimps, the average weaning age
is 5.3 years.

Study co-author Manish Arora stressed the tests were done
with only one Neanderthal sample and "it would be reckless of us to say this
would be the norm for all Neanderthals".

"We look forward to this
technique being applied to more Neanderthal samples so that a more reliable
consensus on weaning patterns in Neanderthals may be made," he said.

The
new method could also aid studies on the benefits of breastfeeding in modern
populations.