Natural history collections as windows on evolutionary processes

Abstract

Natural history collections provide an immense record of biodiversity on Earth. These repositories have traditionally been used to address fundamental questions in biogeography, systematics, and conservation. However, they also hold the potential for studying evolution directly. While some of the best direct observations of evolution have come from long-term field studies or from experimental studies in the lab, natural history collections are providing new insights into evolutionary change in natural populations. By comparing phenotypic and genotypic changes in populations through time, natural history collections provide a window into evolutionary processes. Recent studies utilizing this approach have revealed some dramatic instances of phenotypic change over short time scales in response to presumably strong selective pressures. In some instances evolutionary change can be paired with environmental change, providing a context for potential selective forces. Moreover, in a few cases, the genetic basis of phenotypic change is well understood, allowing for insight into adaptive change at multiple levels. These kinds of studies open the door to a wide range of previously intractable questions by enabling the study of evolution through time, analogous to experimental studies in the laboratory, but amenable to a diversity of species over longer timescales in natural populations.

Phenotypes in phylogeography: Species’ traits, environmental variation, and vertebrate diversification

“…They did so with a large number of phenotypes, including behavior, color, morphology, life history, and ecological traits, among others. Fortunately, many of those efforts are archived in publications or are preserved in natural history collections, providing a sample of Earth's biota that typically extends back to the 19th century, and often includes representative coverage of species' distributions (95,96). For some kinds of phenotypes, such as certain aspects of morphology preserved in museum specimens, natural history collections are a rich source of phenotypic data.…”

“…For some kinds of phenotypes, such as certain aspects of morphology preserved in museum specimens, natural history collections are a rich source of phenotypic data. In contrast, for phenotypes that are not easily preserved-such as behavior, ecological associations, or physiological parameters-field studies will be the ultimate source, although the metadata associated with many preserved specimens often contain important information on behavior, habitat preferences, and other ecological associations (95). Natural history collections also will have a large role in the analysis of more recent evolutionary change in phenotypes (95).…”

“…In contrast, for phenotypes that are not easily preserved-such as behavior, ecological associations, or physiological parameters-field studies will be the ultimate source, although the metadata associated with many preserved specimens often contain important information on behavior, habitat preferences, and other ecological associations (95). Natural history collections also will have a large role in the analysis of more recent evolutionary change in phenotypes (95). For some species, long-term series of collections offer a unique opportunity to infer ancestral phenotypes and how those have changed with documented changes in the environment (97).…”

The value of space‐for‐time substitution for studying fine‐scale microevolutionary processes

“…This is where studies of spatiotemporal patterns of genetic variation can help to evaluate the processes driving changes in genetic diversity (Wang and Bradburd 2014). Of course, direct assessment of the effects of climate change on genetic variation may require temporal sampling (Hansen et al 2012), and new methods have been developed to overcome many of the limitations on the use of historical DNA (Mamanova et al 2010, Carpenter et al 2013, Hykin et al 2015, making temporal landscape genetic studies possible even without new longitudinal sampling programs being undertaken (Bi et al 2013, Holmes et al 2016. However, if space-for-time substitutions are reliable at short time scales, then we already have a strong predictive framework for better understanding the effects of climate change on microevolutionary processes.…”

Climate change, collections and the classroom: using big data to tackle big problems

“…With the explosive increase in digitization of natural history collections, however, many of the constraints on specimen use have been eliminated (Holmes et al 2016). Indeed, the contents of many collections are now digitally available to anyone with internet access.…”