ScienceDaily (Dec. 8, 2011) — A study of South American songbirds completed by the Department of Biology at Queen’s University and the Argentine Museum of Natural History, has discovered these birds differ dramatically in colour and song yet show very little genetic differences, indicating they are on the road to becoming a new species.
The study found differences in male reproductive plumage and in some key aspects of the songs that they use to court females. Now, the group is looking to find the genes that underlie these differences, as these so-called candidate genes may well prove to be responsible for the evolution of a new species. This will allow researchers to gain insights into evolution.
“Studies like ours teach us something about what species really are, what processes are involved and what might be lost if these and other species disappear.”
The findings were recently published in the Proceedings of The Royal Society.
A species is generally defined as organisms that can interbreed and produce fertile offspring. (See here for a more thorough treatment of the definition and its inherent difficulty in pinning down). In this case, it appears that the criteria for selecting mates is beginning to change, and the assumption is that a new sub-population will emerge as a result based on these unique calls and plumage arrangements. Continued isolation will result in genetic variation that will diverge form the original population to eventually create a new type of bird that will be incapable of breeding with the species from which it originated.
Speciation in action. For other (LONG DETAILED) examples, take a look at this site.