Mitochondria are in essence fuel cells that use organics as reductant and oxygen as oxidant. In engineering, increasing attention is being given to the replacement of the internal combustion engine by the fuel cell. According to the Thermosynthesis theory, a similar replacement of heat engines by fuel cells has occurred in biological systems in the distant past. Moreover, the early progenitors of biosystems such as (1) ATP Synthase; (2) biomembranes; (3) bacterial flagella, muscle, and collagen; and (4) the nerve have as engineering counterparts (1) heat engines that work on thermal desorption, (2) electrical capacitors containing a dielectric with a temperature-dependent polarization, (3) polymers such as rubber that contract as a result of a temperature increase, and (4) thermocouples. These biological progenitors ran by convection in volcanic hot springs or by oscillation in the thermal gradient above submarine hydrothermal vents.