A gene from ancient bacteria helps ticks spread Lyme disease
One reason ticks spread Lyme disease so well goes back to a unique evolutionary event. Researchers discovered that an antibacterial enzyme in ticks, Dae2, protects them from bacteria found on human skin, while still allowing them to harbor Borrelia burgdorferi, the bacterium that causes Lyme disease. Ticks acquired the gene for this enzyme 40 million years ago from an unknown species of ancient bacteria.
