chemoautotrophs was Earth's first life form?

Question

pooja195 · Answer

http://www.fossilmuseum.net/Paleobiology/Paleobiologysegues/chemotrophs/chemotrophs.htm I hope that helps its well explained

anonymous · Answer

@debbie17241 This is a bit of a debate.  Personally, I think that autotrophs were the first.  The best evidence I can think of for this is that when you look at the biochemical, metabolic pathways of life, all the heterotrophs require sugars.  Even the absolute most basic function, glycolysis, that is shared by all lifeforms requires sugar.  To my knowledge there is no known non-biological source of these sugars, except from autotrophs.  abhisar and I had a prolonged discussion over this once.

anonymous · Answer

Oh, the sentence ending in "except from autotrophs" implies that they are non-biological.  That is not true.  What I meant was that the ultimate source of all sugars is from autotrophs and there is not a rock or mineral of sugar, unlike salt.