Mice in the house before the dawn of farming

Mice are nothing if not early adopters, new research shows. A study led by archaeologist Thomas Cucchi of the University of Haifa in Israel has discovered that mice were hanging around human settlements as long as 3000 years before the advent of agriculture.

Cucchi’s team studied fossilised mouse molars dating back as far as 200,000 years, all found in the region of a 15,000 year-old hunter-gatherer site in Israel’s Jordan Valley.

By mapping tiny changes to the teeth, the researchers were able to build a picture of how the mouse population in the area fluctuated – and then to correlate with known patterns of human settlement.

The aim was to compare the relative populations of the common house mouse (Mus musculus domesticus), known for being able to live in close proximity to human groups, and a related wild species, the short-tailed field mouse (M. macedonicus), which prefers to keep its distance.

The data indicated that during periods where the hunter-gatherers stayed put for sustained periods of time the house mouse population grew well in excess of that of the field mouse. During periods of upheaval, however, caused by drought or famine, house mouse populations shrank and the field mice did much better.

The study, published in the Proceedings of the National Academy of Sciences, echoes earlier studies looking at fluctuations in mouse populations among the semi-nomadic Maasai communities in Kenya. Both indicate that as soon as hunter-gatherer or nomadic peoples opt to settle for any length of time, other species take advantage of the fact.

“The findings provide clear evidence that the ways humans have shaped the natural world are tied to varying levels of human mobility,” says co-author Fiona Marshall, from Washington University in St. Louis, US. “They suggest that the roots of animal domestication go back to human sedentism thousands of years prior to what has long been considered the dawn of agriculture.”