Minimum sample sizes are intended for well preserved, clean material.
If the sample is too small, it will be submitted for direct combustion. *Ultrafiltration is used to concentrate longer protein molecules and can be used to remove shorter chain proteins more likely to originate from contaminants.
Now, many of the same scientists who made the discovery have radically revised their estimate of the fossils' age, based on an exhaustive new analysis of the cave’s geology.
Physical and chemical pretreatments vary depending on the type of material and the depositional environment from which it came.
It is important to understand the nature of the material being dated as certain organic fractions are more appropriate than others, depending on the environment.
However, that 18,000-year-old date was based on only a geological analysis of the fossils' surroundings and not on direct analysis of the bones themselves.
And the complexity of the cave's geology initially misled the scientists, says Matthew Tocheri, a paleoanthropologist at Lakehead University in Thunder Bay, Ontario, Canada, and a member of the discovery team.
Liang Bua is a cathedral-like cave with a high domed ceiling.