How do collections aid in research?

In the past, mammal research has mainly focused on comparisons of changes in physical traits over time and space. As technology has advanced, research studies that use museum collections now often focus on genetic analysis or examination of stable isotopes. Tissue samples at collection are very important. Although these tests are accurate and can tell us a lot about an individual as well as a changes in a population over time, examination of the study skin or skeleton of a particular individual is still needed for confirmation of the proper identification as well as to detect physical changes over time. 

If a researcher wants to use a tissue sample from a prepared specimen, the collections committee in the museum reviews and approves the research prior to sampling. They consider the rarity of the specimen and the size of the sample needed for the researcher to conduct their research.