In Drexler's view of knowledge evolution, the evolutionary process can be accelerated if the transmission is made more efficient. If the time between when an idea undergoes expression and reaches evaluation is sped up more ideas will enter into the evolutionary process.

From WordNet (r) 1.6 [wn]:

  transmission
       n 1: the act of sending a message; causing a message to be
            transmitted [syn: {transmittal}, {transmitting}]
       2: communication by means of transmitted signals
       3: the fraction of radiant energy that passes through a
          substance [syn: {transmittance}]
       4: an incident is which an infectious disease is transmitted
          [syn: {infection}, {contagion}]
       5: the gears that transmit power from an automobile engine via
          the driveshaft to the live axle