DANCEST 805 Lecture Notes - Lecture 21: Billion Years, Nernst Equation, Membrane Potential
Document Summary
It took 2/3 of the duration of existence of the earth before life formed. It took 3 billion years for the progress of unicellular organisms to multicellular organisms. Since life evolved it has never become extinct. Since life emerged there has always been somewhere on earth with a temperature between 0 and 100 celsius. There are 3 origins of life on earth: higher being, panspermia, abiogenesis. Creation via a higher being is supported by the sheer statistical improbability of life appearing spontaneously. Panspermia (all seed), life originated somewhere other than earth and was transported via another method. Does not strictly answer the ultimate question of the origin of life. Yet interplanetary/stellar travel involves enormous distances, times and extreme conditions. It was rich in organics, containing 70 types of amino acids, some of which are used for life on earth, including glycine and b-alanine. Most were of left-hand chirality as are all aas exclusively used for life on earth.
