Research on garter snakes’ resistance to tetrodotoxin (TTX), the toxic secretions of the Rough-skinned Newt (Taricha granulosa), continues. As far as the toxic arms race is concerned, a new study published today suggests that the garter snakes are winning. While the most toxic newts are found in the same areas as the most TTX-resistant snakes, the study also found that in one-third of the areas, even the least resistant snakes could manage the most toxic newts. This suggests that there is no pressure for the snakes to evolve even greater resistance; the study argues that there are few snake genes involved in toxin resistance, allowing it to evolve quickly. The biologic limits of the newt itself is another factor: TTX is secreted away in the amphibian’s skin, but is toxic to the newt itself, which limits the amount that can be produced. Science Daily, Times Online.

Previously: Garter Snakes Absorb Newt Toxins as a Defence Against Birds; Newts, Garter Snakes Engaged in Toxic Arms Race at Molecular Level.