Key Takeaways

• Isotope analysis helps archaeologists and forensic experts determine whether an individual grew up locally or migrated from another region.
• Tooth enamel preserves early-life chemical signals, while bone reflects more recent years due to natural remodeling.
• Researchers compare isotope values to regional baselines, known as isoscapes, built from environmental sampling.
• Diet, trade, environmental overlap, and post-burial changes can complicate geographic interpretation.
• Ethical guidelines require careful sampling, preservation checks, and consultation with descendant communities.

Danielle Kurin, PhD, is an anthropologist and former University of California Santa Barbara faculty member whose work bridges bioarchaeology, forensics, and Andean research. Danielle Kurin directed the Phillip Walker Bioarchaeology and Forensic Bone Lab, where she supervised students analyzing human remains through DNA, isotope testing, and environmental evidence. Her field research has focused on Peru and other regions of the Andes, and she previously led the Andahuaylas Bioarchaeology Project. In addition to academic research and teaching in osteology, human evolution, and forensics, she has applied archaeological methods in contemporary contexts, including search efforts following the 2018 Montecito mudslide.

This combination of laboratory science and field investigation provides context for understanding how isotopes preserved in teeth and bone can help trace patterns of past human movement.

Tracing Past Movement Using Isotopes in Teeth and Bone

When archaeologists or forensic analysts examine human remains, they often start with a question: Did this person grow up here, or did they arrive from somewhere else? That distinction can reshape a migration story or help narrow an identification when records or belongings do not answer it. Isotope analysis helps by reading chemical patterns the body absorbs through food and water.

In plain terms, isotope analysis compares values in teeth or bone with values measured across a landscape. Isotopes are slightly different forms of the same element, and local geology and water sources influence regional ranges. Labs select isotope systems that match the question, such as strontium, oxygen, and hydrogen.

Tooth enamel works well for early life because it forms in childhood and then stays stable. Unlike most tissues, enamel does not remodel, so it keeps the signal from when it formed. That stability makes enamel a “childhood snapshot” even if the person moved later.

Bone tells a later part of the story because the body constantly breaks down old bone and replaces it with new tissue. That turnover means bone chemistry often reflects more recent years rather than childhood. Researchers can compare enamel and bone to ask whether the person’s early-life and later-life signals point to different regions.

To interpret a sample, research teams build regional baselines, often called isoscapes. They measure local water and the plants or animals that reflect what enters the food chain, then map the expected range for each area. In some regions, trained volunteer sampling programs help fill gaps in those maps.

A simple example shows how the pieces fit. Enamel values might align with a highland range, while bone values align with a coastal range where the person was buried. That mismatch supports a change in residence between childhood and later adulthood, but it does not identify a precise town.

Diet can complicate interpretation because foods and drinks carry signals from where they were produced. If a person relied on imported or traded foods, the chemistry may look less “local” even without long-distance movement. For that reason, teams interpret isotope results alongside site history and burial context instead of treating lab numbers as a standalone verdict.

Mapping limits also matter. Some regions share similar isotope ranges, and many areas lack dense reference datasets, which reduces geographic precision. Researchers also watch for post-burial changes if soil minerals or groundwater alter the chemistry after death.

Labs reduce misinterpretation by confirming that bone or enamel remains were well preserved before drawing conclusions. They compare multiple readings or use screening steps to flag samples that groundwater or soil minerals likely altered after burial. If the material does not hold a clean signal, analysts avoid location claims or state the limits plainly.

Ethics shapes this work as much as method because isotope testing removes a small piece of tooth or bone and permanently changes the remains. Professional guidance emphasizes dignity, stewardship, and consultation with descendant or affiliated communities when appropriate, especially for groups with histories of harm. Repatriation rules and related policies can require justification and disclosure for destructive analysis, and documented repatriation delays increase pressure for clear permissions and timelines before sampling.

Used carefully, isotope testing helps evaluate whether a burial likely reflects long-term local residence or later movement across regions. Better baselines and more complete mapping make comparisons more reliable, especially where environmental sampling remains thin. The method cannot assign a “hometown,” but it can narrow plausible regions enough to challenge assumptions and sharpen interpretation.

FAQs

Who is Danielle Kurin?

Danielle Kurin, PhD, is an anthropologist and former University of California Santa Barbara faculty member specializing in bioarchaeology and forensic research. She directed the Phillip Walker Bioarchaeology and Forensic Bone Lab and has led field projects in Peru and the Andes.

How does isotope analysis help trace human movement?

Isotope analysis measures chemical signatures absorbed through food and water and preserved in teeth and bone. By comparing these values to regional environmental baselines, researchers can assess whether a person likely moved between regions during their lifetime.

Why is tooth enamel important in isotope studies?

Tooth enamel forms during childhood and does not remodel, preserving a stable early-life chemical signal. This makes enamel especially useful for identifying where someone likely grew up.

How does bone differ from enamel in migration research?

Bone continuously remodels throughout life, reflecting more recent geographic signals rather than childhood origins. Comparing bone and enamel values can reveal whether a person relocated later in life.

What are the limitations of isotope analysis?

Overlapping regional isotope ranges, imported foods, incomplete environmental maps, and post-burial chemical changes can reduce precision. For this reason, isotope findings are interpreted alongside archaeological context and ethical considerations.

About Danielle Kurin

Danielle Kurin, PhD, is an anthropologist and former UCSB faculty member who directed the Phillip Walker Bioarchaeology and Forensic Bone Lab. Her research focuses on ancient populations in Peru and the Andes, and she has led long term field projects such as the Andahuaylas Bioarchaeology Project. Trained in osteology and forensic analysis, she has also served as a consulting expert for museum exhibitions and community investigations involving human remains.