Herbarium Genetics
Herbarium genetics
Herbarium collections around the globe hold nearly 400 million plant specimens, dating back hundreds of years, and have proven to be an invaluable resource in understanding plant biodiversity. One under-explored aspect of herbarium collections is the genetic material that they can supply. As DNA extraction and sequencing technologies continue to advance, the genetic data stored in these collections is becoming increasingly accessible.
Sequencing herbarium specimens may hold the potential to transforming our understanding of the the genetic diversity of past and present plant populations. But how can we maximize the potential of these collections and where should we begin?
Turning specimens into historical populations
In our first study (currently in review), we explore the potential for these millions of herbarium specimens to represent historical populations. As with many genetic analyses, you need multiple specimens of the same population to estimate metrics like genetic diversity or effective population size. Although herbarium specimens were not collected for these purposes, the sheer number of specimens means that we can effectively cluster them together in time and space to represent historical populations. This clustering method uses species-specific temporal and spatial thresholds to identify biologically meaningful populations.
The specimens in these populations can then be sequenced to estimate historical metrics of genetic variation and monitor genetic change.
Applications of genetic data
In a follow up study (also in review), we explore the potential applications of genetic data from herbarium specimens, specifically those that could contribute the most to our understanding of how plants are coping with global change and inform conservation and policy decisions. These include tracking temporal changes in genetic diversity, determining the genetic basis for responses to climate change, validating genomic predictions, understanding genetic patterns of biological invasions, and exploring the genetic warning signs of local extinction.
For each application, we propose a case study that exemplifies the unique ability of herbarium specimens to provide valuable insight.
Collaborators:
Isaac Eckert
Cameron So
Olivia Rahn
Laura Pollock
Rowan Barrett