Mining Nature’s Most Efficient Storage Medium

If someone were to ask you what is the most efficient way to store information, what would you say? In the early 1900s, you would have been justified in answering with something like, “a well-organised file cabinet,” or, “a building filled with books with small text.” Since that time, our capacity to compress data has progressed so far that a little 4” x 3” hard drive can now store as much information as an entire library! However, there is another way of storing data that dwarfs the capacity of even the most efficient hard drives, and it wasn’t even invented by humans …

Deoxyribonucleic acid – more commonly known as DNA – is the ultimate form of data compression, manifesting a staggering capacity for storing large amounts of information in a package so minuscule that it cannot be observed with the naked eye. Often called the “code of life,” organisms look and operate as they do as a consequence of their DNA, similar to how computer code determines how virtual programs look and operate.

An artistic depiction of a DNA molecule with binary code binding the two strands of DNA. Photo © istock.com/ymgerman

The totality of an organism’s DNA is called its “genome”, and the genome of every individual organism is different, save for a few exceptional circumstances (e.g., clones). If we can access the information contained in an organism’s genome, there are seemingly infinite ways that we can process the information to learn about the individual organism, its relatives, and the species to which it belongs. This is the fundamental idea underlying the field of Molecular Ecology.

Molecular Ecology is a rapidly expanding field of research that uses DNA to illuminate biology, demographics, population dynamics, and/or myriad other factors that contribute to a species’ potential to persist and thrive, and this information can help us calibrate management actions and set conservation goals. Indeed, research in the field of Molecular Ecology is increasingly expanding our understanding of shark and ray biology and conservation needs. Of course, to make use of the vast stores of information contained in DNA, we first have to collect some.

There are different ways to collect DNA from wild animals, some of which are indirect – like extracting DNA from environmental samples – and some of which are direct, like taking tissue samples from individual animals. Most Molecular Ecology research – including our eagle ray close-kin mark-recapture project – rely on direct methods, where DNA is obtained from tissue samples collected from individual animals. If we have samples from many individuals, then we can use the information contained in the DNA of each sample to make inferences about the whole population and/or species. This is the foundational premise of our work with white-spotted eagle rays, where we are using DNA to identify related individuals and then comparing the proportion of related to unrelated individuals among our samples to estimate population abundance.

A series of blog posts following this one will elaborate on our methods and findings from our eagle ray research, focusing on each of the three broad categories of work involved: fieldwork, labwork, and bioinformatics (a.k.a. data analysis). By the end of this short series of blogs, hopefully, you will agree that the field of Molecular Ecology is a very exciting and useful field of research for shark and ray conservation.