Museums and other natural history collections (NHC) worldwide house millions of specimens. With the advent of molecular genetic approaches these collections have become the source of many fascinating population studies in conservation genetics that contrast historical with present-day genetic diversity. Recent developments in molecular genetics and genomics and the associated statistical tools have opened up the further possibility of studying evolutionary change directly. As we discuss here, we believe that NHC specimens provide a largely underutilized resource for such investigations. However, because DNA extracted from NHC samples is degraded, analyses of such samples are technically demanding and many potential pitfalls exist. Thus, we propose a set of guidelines that outline the steps necessary to begin genetic investigations using specimens from NHC. Museums and other natural history collections (NHC) worldwide house millions of specimens. With the advent of molecular genetic approaches these collections have become the source of many fascinating population studies in conservation genetics that contrast historical with present-day genetic diversity. Recent developments in molecular genetics and genomics and the associated statistical tools have opened up the further possibility of studying evolutionary change directly. As we discuss here, we believe that NHC specimens provide a largely underutilized resource for such investigations. However, because DNA extracted from NHC samples is degraded, analyses of such samples are technically demanding and many potential pitfalls exist. Thus, we propose a set of guidelines that outline the steps necessary to begin genetic investigations using specimens from NHC.
IntroductionGiven that evolution is change over time, documenting and understanding temporal patterns has long been at the heart of evolutionary studies. In disciplines such as palaeontology, inferences about evolutionary processes are drawn from the analyses of temporal patterns in the fossil record. Similarly, our understanding of microevolutionary processes (i.e. changes in gene frequencies over time) has often involved the analyses of records taken over several years; Dobzhanksy's [1] early studies of microevolution among Drosophila used this approach, a tradition that continues among students of this model organism today [2]. However, such microevolutionary studies were often limited to certain taxa and questions because the time available to document temporal changes was often limited to a few generations. How can these limitations be overcome? Long term studies, running over several decades, are one possibility and they are yielding fascinating insights, for example, into the role of reinforcement and character displacement in adaptive radiation and speciation [3,4]. Another approach, which gives longer time series, is to extend the data back in time using well preserved fossil samples or specimens from natural history collections (NHC). Here, we review the use of specimens from NHC for the ...