How did we identify these spiders?
We used a technique called DNA barcoding to identify these spiders. Just like products in a grocery store can be differentiated with a universal product code, animals can be differentiated by a region in their mitochondrial DNA that varies at or about the species level. The “barcode” for animals is a short (less than 700 base pairs) region of the cytochrome c oxidase (CO1) gene, a gene that codes for proteins involved in cellular respiration.
Why is this so useful?
Animals are usually identified to species by their morphology. But doing this with little animals like spiders is difficult because the differences from one species to the next can be quite subtle, usually involving small differences in their genitalia. When they are juveniles, identifying a spider to species can be impossible because the genitalia are not yet developed. But with DNA barcoding, anyone in a modern biology lab can generate DNA barcode data, compare that data to a library of similar DNA sequences (BOLD), and match an unknown specimen to specimens that have already been identified. Some of our specimens do not have species names because there is no match in the database (we were the first ones to barcode that taxa) or there is a match but no expert has put a name on that group of specimens.
About the BOLD Identification Number (BIN)
Barcode Index Numbers (BINS) are DNA sequence clusters that closely approximate species.
For more, please see:
http://www.boldsystems.org/index.php/Public_BarcodeIndexNumber_Home
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0066213