To translate from Genomics, to examine the microbiome–the microorganisms that live on or in a certain habitat (e.g., your gut or skin, the surface of your toothbrush, a tomato, etc.)–we get DNA from that habitat, sequence it, and then assemble those small sequences* into larger sequences. We can then compare these larger sequences genetic databases to determine where those larger sequences came from. If we see that a lot of our sequences match the bacterium E. coli, we can assume that E. coli is an important part of the microbial community we sampled (there are procedures we can use to remove human sequences–in these studies, humans are a contaminant). One of the common programs used to assign sequences to organisms is known as MG-RAST. Gonzalez et al. found (the authors of the poster) that thirty percent of all publicly-available microbiome samples, when analyzed by MG-RAST, contain… Ornithorhynchus anatinus–the platypus.
Which leads the authors to snark, “[this] could lead to believe that platypus prefers warm, saline, and alkaline habitats, but… lives everywhere.”
Heh. And, yes, the software to fix this problem is called Platypus Conquistador.
*Without getting into the details, we actually sequence very small pieces of genomes and then stitch them together (this is called ‘assembly’). If you’re a biologist, this is obviously oversimplified–don’t be pedantic (or at least, start your own blog and be pedantic there).