Strontium signatures

[goddessodd]

I know that it is possible for scientists to locate the birthplace and the home locales of ancient humans by using their strontium signature...each place on earth having it's own distinct strontium level, which passes into the animals the humans eat, which then ends up in bones and teeth. Would I be correct in assuming that humans have lost their strontium signatures, as we now eat foods from all over the world? Would vegetarians also acquire strontium levels sufficient to place them in the world? Today I have had tomatoes from South America, organic greens from Oregon, and oats from who knows where. If the strontium signatures are no longer valid, when did we lose them?
Ever Curious,
Goddessodd

[The Cat]

I've never heard of this and I took a lot of nuclear physics. Do you have any cites of incidences where this has been used to pinpoint the birthplace of an ancient human. I'm just curious if this idea comes from one of the psuedo-scientists you see on the discovery channel. The discovery channel will make you believe that cold fusion is possible if you're not careful.

I find it hard to believe that this would work with any great deal of accuracy. I'm not ruling out the possibility however. Does it just pinpoint what continent you're from, or what country? Or does it tell you exactly what cave you lived in the stream you drank from. Even in the ancient world goods could travel thousands of miles.

[spingears]

Originally Posted by goddessodd

I know that it is possible for scientists to locate the birthplace and the home locales of ancient humans by using their strontium signature...each place on earth having it's own distinct strontium level, which passes into the animals the humans eat, which then ends up in bones and teeth. Would I be correct in assuming that humans have lost their strontium signatures, as we now eat foods from all over the world? Would vegetarians also acquire strontium levels sufficient to place them in the world? Today I have had tomatoes from South America, organic greens from Oregon, and oats from who knows where. If the strontium signatures are no longer valid, when did we lose them?
Ever Curious,
Goddessodd

Lose them? No they are alive and well.
Cool Tool The Bone Readeron Pg. 1
May not be applicable to todays people due to mobility and world wide food sources.

[goddessodd]

Yes, that was one of the articles I read about this-thanks for the site. I was really just curious to learn if this science could help identify the origins of modern day Jane and John Does. My guess is that this is not applicable to modern humans, as we almost never consume locally produced food.

[bizzwire]

Several years ago I went to a lecture given by a South African scientitst (I forget his name) who was employing the same approach to identify the origin of confiscated ivory. I believe he was looking at Carbon isotopes incoporated in the ivory which varied depending on the locale of the vegetation the elephant was eating while alive.

[Polycarp]

I suspect strongly that the truth is somewhere between "it's total garbage" and "it's accurate" -- strontium substitutes for calcium in chemical reactions to a certain low-but-real level; that's why strontium-90 fallout was (and is) considered so dangerous. This would mean that natural sources of calcium will have varying levels of strontium, depending on whether there is a strontium source nearby affecting the degree to which strontium substitutes.

It would not be the case that you could take a given sample of bone or nerve tissue to a strontium-signature expert and have him convincingly say, "This sample came from Perm oblast, Russia" or "...from southwest Kansas or the immediately-adjacent northern border of Oklahoma." But given the variant strontium levels, it would be possible to determine where within a given range of possible sources a given sample came from. E.g., given a rhinoceros horn known to have been taken from a Sumatran rhino, it would be possible to say, "It came from Negeri Sembilan province, Malaysia, or somewhere immediately nearby that province," as opposed to the other places Sumatran rhinos might live, because of the degree to which strontium replaces calcium in the horn's composition.

The same, by the way, holds true for the carbon issue mentioned -- C-12 is by far the most common isotope, but C-13 is concentrated in colder climates. So bone samples from two 29-year-old women, one from Whitehorse, Yukon, and one from Orlando, Florida, would be distinguishable by the ratio between C-12 and C-13 in their bones (presuming them to be long-term residents of the two communities).