Are the Transformers a "species"
In the G1 cartoon the Decepticons and Autobots shared different origins. While it's unclear exactly how each robot descended from the other (although it has something to do with sparks and a formerly organic Cybertron) the Decepticons were Military hardware and the Autobots were consumer goods. In addition there were other races, including the Junkions and Paradrons (who lived on a peaceful planet).
In the Japanese continuity the race further split with the creation of the Headmasters, microbots and Transectors (Powermasters) who were Autobots who transferred their "souls" into human bodies who controlled lifeless robot bodies.
In the United States the G1 cartoon continued to evolve, producing the Maximals and Predacons.
G1 differed the comic. In the comic, written by Marvel, the Autobots and Decepticons were simply war factions who split off for reasons unclear, presumably resources and power. However, in G2 it was revealed there was indeed a distinct race known as the Cybertronians.
With Dreamwave and IDW it appears the Decepticons and Autobots (even blended with characters from Japanese and G2 continuities) are again simply war factions. Megatron's Decepticons coming mostly from the pits; a gladitorial combat Arena. Dreamwave, however, revealled that the distinction of Autobot and Decepticons are not so simple. The Wreckers, The Mayhem Attack Squad, The Protectobots, the Dynabots and many many other subsections are loosely held together to form those two warring factions.
In Armada (UT), the warring factions are not two races, but rather groups of Transformers who have been subtley influences by Unicron into war. Their main objective is to fight over smaller Transformers known as minicons, later energon and then finally the Cyber planet keys. These Transformers are capable of easily upgrading their forms, which can be seen as a method of evolving/mutating.
RiD definitely made the Decepticons, Autobots and Predacons different species. Aside from the Decepticons, the origins are unknown.
In addition, The Japanese continuity, over the years has pushed heavily the notion of Transformers be able to possess brothers, fathers and possibly mothers in the same way humans do. The US continuity tended to stray away from this, leaning more towards the notion that any relation between two robots was more or less related to general appearance.