While past work has often examined the effects of transmission mode on virulence evolution in parasites, few studies have explored the impact of horizontal transmission on the evolution of benefits conferred by a symbiont to its host. Here, we identify three mechanisms that create a positive covariance between horizontal transmission and symbiont-provided benefits: pleiotropy within the symbion...

Human type 1 T-cell lymphotropic virus (HTLV-1) infection has been described in many areas of the world, including Caribbean countries, Japan, Africa, Oceania and South America. In this review we define the endemicity of HTLV-1 in the country proposing four epidemiological criteria. Then we discuss the core subject of the review, which is the vertical transmission of HTLV-1. This mechanism is o...

The finding that the synapses relaying sensory input to the cortex may have different properties than intracortical synapses has implications not only for sensory processing, but for the role of noise in neural computation as well.