![crow zero uniform crow zero uniform](https://lastfm.freetls.fastly.net/i/u/770x0/3f31bfbc983349b2aea613679a35f40f.jpg)
In evolutionary terms, the two populations thereafter went their separate ways. However, during the period of their isolation, the populations in Southwestern and Southeastern Europe had diverged from each other to such an extent that they no longer interbred at the same rate, i.e.
![crow zero uniform crow zero uniform](https://pbs.twimg.com/profile_images/3224589505/d3d20a510c785e231ef5b570181a5826_400x400.jpeg)
When the climate improved at the end of the last glacial maximum, they were able to recolonize their original habitats. The ancestral population of crows in Europe began to diverge during the Late Pleistocene, at a time when the onset of glaciation in Central Europe forced the birds to retreat to refuge zones in Iberia and the Balkans.
![crow zero uniform crow zero uniform](https://my-live-05.slatic.net/p/c937bf4e454cdb22349f017905c9c643.jpg)
Their findings appear in the online journal Nature Communications, and imply that all corvid species were originally uniformly black in color. The scientists have now identified a crucial mutation that affects this character. Genetic analyses have already suggested that differences in the color of the plumage play an important role in limiting the frequency of hybridization between carrion and hooded crows. LMU evolutionary biologist Jochen Wolf and his team are studying the factors that contribute to the divergence of the two populations at the molecular level. For this reason, the two forms have become a popular model for the elucidation of the processes that lead to species divergence. Although crosses between the two forms can produce fertile offspring, the region of overlap between their geographical distributions in Europe is strikingly narrow. The carrion crow's feathers are soot-black, while the hooded crow's plumage presents a particolored combination of black and light gray. The carrion crow and the hooded crow are genetically closely related, but they are distinguishable on the basis of the color of their plumage.