Ravens have been harbingers of doom, witches’ familiars, and dastardly throughout folkloric history. And, like ravens themselves, their evolutionary path has been anything but cut and dry.
Speciation is fairly commonplace and well known theory in evolution. Speciation is when one species diverges into two. Creatures produced through speciation are common and well known in our daily life - finches, croatian lizards, and squirrels that live in the rims of the Grand Canyon are all examples. A new species is not able to reproduce with members of the original population.
But, ravens are changing that. Scientists have recently discovered that distinctly separate lineages of ravens, which have evolved separately for about 1-2 million years, now appear to be consolidating. In other words, it appears as if raven’s are involved in speciation reversal.
The study that discovered this utilized DNA samples from ravens over a period of about 20 years. The evidence they present shows that common ravens on the western coast of North America have split into 3 genetically distinct groups. However, two of these lineages “appear to be in the process of melding back into one, scientists report Thursday in the journal Nature Communications.”
According to National Geographic, “two lineages—or groups that were on their way to becoming separate species—become one. Scientists call this “reticulate evolution,” says Kearns, and it’s been seen in only a handful of other species, including finches and two kinds of fish.” These species, specifically, are the Holartic and California lineages.
The study involved a genetic analysis of 400 birds spanning the geographical range of he two two populations. It now appears that the two populations have combined to create a hybrid of two original linages. According to the Guardian, “the pure California type no longer exists)”
Despite these revelations the birds seem to exhibit the same behavior, they sound the same, and do no seem to continue interbreeding with the other two groups, despite the possibility since their geographical ranges overlap.
Scientists are currently investigating what prompted the merger between the two populations. Overall, this finding reveals just how complicated biology really is...as it seems to suggest that we might need to rethink some things we thought were set in stone.
This is an image of "A Northwestern Crow at Stanley Park, Vancouver, British Columbia, Canada." It is liscensed under CC BY-SA 2.0. It was taken by Snowmanradio.