Carl Sagan’s Cosmic Calendar (illustrated as a comic strip here) maps the entire history of our cosmos onto a single year.

On October 12 (representing 3 billion years ago), life first harnesses solar energy.  Thanks to photosynthesis, the Earth begins to green.  Today, photosynthesis is employed by plants, algae, and many forms of bacteria.

It’s worth a moment’s contemplation that our modern industrial age would not be possible without photosynthesis: sunlight converted into matter by zooplankton and algae and then converted into petroleum under heat and pressure over great lengths of time sustains our fossil fuel-dependent lifestyle.