Question: Have you been to different places in the world to find bones and their DNA?

Jennifer Bates answered on 8 Nov 2016:

I haven’t been to look specifically for bones, but we often find them on excavations. I work mainly in South Asia, and its usually animal bones we find there, but on some digs in Malta lots of human bones were found, and on my first excavation abroad (which was in Turkey) we found a little cemetery next to a Byzantine church, and a baby skeleton in the Bronze Age levels beneath that.

We don’t often do DNA analysis because you have to ask the question – what do we want to find out about these bones? And DNA doesn’t really tell us much. Usually archaeologists do something called isotopic analysis, which is looking at the chemical signatures in the bone formed from what that person was eating or drinking. By doing that we can think about how much meat they ate, what kind of grasses they were eating (e.g.: maize or wheat) which could tell us about diet and climate, whether they were eating a freshwater or marine diet, and if we have teeth, we could do oxygen isotope analysis to look at where they grew up. Different bones tell us about different parts of a person’s life because all bones remodel (change) over time. Long bones like the thigh bone (femur) can take about 15 years, smaller bones like ribs can take about 5 years, while teeth are fixed so tell us about childhood. If you are lucky and get a mummy (like in Egypt or Peru) you might get skin tissue which takes a very short time to change, while hair grows at a centimetre a month. So by using different bones or tissues you could look at different parts of the life of a person!