What is the fine-grained topic of the following text: Our study illustrates how canine teeth, and potentially other structures such as tympano-periotic bone, waxy inner earplugs, or otoliths, may be used to explore links between genetic variation and important life-history traits in free-ranging vertebrate populations. Only return the topic.
Using canine teeth and other structures to explore genetic variation and life-history traits in free-ranging vertebrate populations.