Since peat is laid down in layers over thousands of years, scientists can trace changes in the natural environment as well as human influence.

The two scientists stared, and traced the diagram again, and ogled each other.

Some scientists trace the ability to secrete enzymes to the early role of melanocytes.

Similar research is helping scientists trace the Diaspora of Jewish populations.

Working with police, the scientists traced the recovered artifacts to a site near Sipan that had been looted for centuries.

The scientists traced the gene back to one stallion, Impressive, whose popularity as a stud lay behind the spread of the condition.

And scientists could trace the origin and fate of every single cell.

Since then, scientists have traced many of the minute mechanisms by which cells commit suicide.

The scientists trace the trouble to high levels of nutrients, in particular nitrogen, that flow out of the Mississippi and into the Gulf.

Human scientists traced human origins back to this one primitive hominid woman.