origin of life
The following is my summarization of support for the hypothesis that life could have originated on Earth around thermal sea vents.
The second law of thermodynamics is increasing entropy. Energy/matter becomes more evenly distributed over time. If you have a hot thing next to a cold thing, the hot thing gets colder and the cold thing warms up until their temperatures reach equilibrium in the middle.
Thermal sea vents bring to mind bubbling, hot mixing with cold, porous sediment structures, and ocean currents. It’s a dynamic environment with churning forces and unique surface areas. There are lots of little pockets of novelty.
It’s an opera of heat dissipation. The extreme temperature gradient across the Earth’s mantle and sea floor gives rise to chemical reactions and structures that more efficiently dissipate heat.
These bullets are from a slide presented by Nick Lane:
Free energy powers growth.
All growth is thermodynamically favorable overall.
Biology lowers kinetic barriers to thermodynamically favored reactions.
Heredity is a form of growth - doubling by exact copying.
All forms of selection depend ultimately on growth - growth comes first.
Growth combines carbon and energy metabolism.
Energy metabolism is coupled to endergonic aspects of growth.
Biochemistry is close to equilibrium.
Growth is driven by environmental disequilibria.
In his book Life Ascending, he examines how do you go from inorganic to the first cell membrane? How does RNA replicase emerge? What about the move from single-cell to multicellular life? These are unsolved but under active research. He frames these inventions as efficiency mechanisms for heat dissipation.
In an unscientific way, the phrase “free energy powers growth” is also kind of inspiring. In a forest every photon from the sun is free energy and plants compete for it to fuel their growth. Wind that moves tree trunks and branches can be transferred into momentum that moves fluids up and down the tree. Coral reefs do something similar to extract nutrients, using the free energy of tidal motion. Pitcher plants use raindrop impacts to fling insects into their trap.
There is a beauty to the idea of being receptive to free energy. Where ever energy is available use it to power growth.