Most people are at least somewhat familiar with the process of speciation. An animal exists in a certain environmental situation over a certain range. In time, part of the environment in the single specie’s range may change prompting biological changes in part of the original species. Over time, a new species comes into being.
While scientists understand the process of speciation, they have now discovered that ravens that were once on there way to becoming two separate species are now merging back into a single lineage.
According to scientists, Holarctic ravens and California ravens went their own ways as two separate lines as long as two million years ago. Each line had its own genetic identity distinguishing one from the other.
After studying over 400 birds from both of these raven lineages scientists have discovered that some populations of the two have merged together to form a mixed lineage that contains DNA from the Holarctic raven and the California raven. Some of the ravens only possessed Holartic raven DNA. There are currently no ravens in existence that are purely of the California lineage. There is a third raven lineage known as the Chihuahuan raven.
Scientists are puzzled as to why this merger of the lineages occurred. The discovery is so remarkable that zoologists believe that they may have to reconsidered what a species actually is.
What troubles scientists is that the Chihuahuan ravens are keeping their separate identities as a separate lineage even though their territories intersect with both the Holarctic and Holarctic-hybrid ravens.
In order to learn more about why this phenomenon has occurred with ravens, researchers plan to attempt the recovery of DNA samples from ravens that lived in the past. The goal is to isolate the time when the transition from two distinct lineages back to a single lineage occurred.
