HIDDEN behind the popular displays at many of your favorite natural history museums — in their basements, back rooms and, increasingly, off-site facilities — sit humanity’s most important libraries of life, holding not books but preserved animal and plant specimens, carefully collected over centuries by thousands of scientist explorers.

These specimen collections serve as the bedrock of our system of taxonomy — the rules by which we classify life — and are integral to our understanding of the threats, origins and interrelationships of biodiversity. And yet, thanks to budget cutbacks, misplaced ethical critiques, public misconceptions and government regulations that restrict scientists while failing to restrict environmental exploitation, the continued maintenance and growth of these libraries is in danger.

Though most visitors never know they are there, natural history collections are as critical to modern biologists as libraries are to journalists and historians. Indeed, like good literature, each museum specimen allows reinterpretation by every person who examines it.

A taxonomist looking for minute differences between species, and a biogeographer investigating species distributions across a landscape, will find the same specimen valuable for different reasons, as will an evolutionary biologist resolving the interconnectedness and history of life, and an ecologist piecing together the intricate functions of whole ecosystems. These collections are particularly critical in today’s era of rapid ecological and climate change, providing a unique and vitally important glimpse into ecological conditions of the past.