Throughout the evolution, a glacier advanced on the Pacific Northwest, it was able to form a natural ice barrier, as a result the crows were divided into two villages. These groups of crows began to diverge into two separate species that the ornithologists thought they distinguished by small differences from some crows with others. These differences were found in their body measurements and the sounds they made; Or so it seemed...
After going through the speciation process of hundreds of thousands of years.
The two specimens of crow, the one of the northwest and the American crow, returned to unite, began to procreate, according to new genetic tests. Crows have been hybridizing on a 900-kilometer long strip in the Pacific Northwest.
What this study tells us is that a new raven breed has been created.
"It implies that speciation is not a unidirectional process," says Dave Slager, lead author of the study and a doctoral candidate in biology at the University of Washington. "You can even go back sometimes."
Scientists say that the two species of crows separated since 1858. The northwest crow is a bird of beaches and marshes of the Pacific Northwest, a little smaller than the ubiquitous American crow capable of emitting more hoarse sounds, according to ornithologists and connoisseurs of birds.
It has become very difficult to know if these birds hybridize and, if so, with what time range they do, or not. Genetic information shows amazing results.
The study shows that species do not need to have defined limits Claire Curry, a scientist at the University of Oklahoma “Natural selection and species dispersion have not ended, this is not in the past, and it is totally cool to have the opportunity to study the crows