[T]axonomy – the science of classifying organisms – would be so much easier if life forms came with barcodes…
Interestingly enough, there's actually something to that hopeful desire. Since the turn of the century, a group of scientists has attempted to classify species by sequencing their DNA, specifically DNA from a specific region inside mitochondria, the energy production centers of cells.
This 'DNA barcoding' doesn't work well for all forms of life, particularly plants, but it does work exceedingly well for animals. In a 2016 study, researchers used mitochondrial DNA to classify bird species then compared their results with those of traditional methods. The two classification systems agreed in 94% of cases.
[Researchers Mark Stoeckle and David Thaler] found that older species tended to have a greater average difference in mitochondrial DNA. This makes sense, as genetic adaptations tend to accumulate over time, which can lead groups of individuals within a species to diverge into entirely new species. When they do, their mitochondrial DNA is noticeably different.
“If individuals are stars, then species are galaxies. They are compact clusters in the vastness of empty sequence space,” Thaler analogized.
The study demonstrates that “Big Data” can play a pivotal role in classification, and has the potential to infuse taxonomy with a needed measure of objectivity.
Read full, original post: What Can 'DNA Barcodes' Tell Us About Evolution and Ourselves?