Trees of Life

There are two ways we know in which life can develop purely from non-living
matter - photosynthesis and chemosynthesis.

Why then, do we try to construct a tree of life originating back to a single
point? As organisms using photosynthesis and chemosynthesis are entirely
independent, would it not be more logical to have two separate trees of
life - basically one for plants and one for animals, or do we have real
evidence of a common ancestor? (I'm consciously leaving cyanobacteria out of
this as I don't think it affects my underlying point.)

A secondary area intrigues me. Outside of those basic organisms that use
photosynthesis or chemosynthesis, all other forms of life grow and develop
by consuming other organisms - cow eats grass, man eats cow, etc.

Do we have any knowledge of at what point in evolution this process of
organisms consuming organisms began?


.

Relevant Pages

  • Re: Trees of Life
    ... It seems to me that the first forms of life, by definition, had to be ... The only way they could get energy was either by photosynthesis ... As far as I can see, chemosynthesis is the more likely of the two as most ... the Theory of Evolution generally assumes that life ...
    (talk.origins)
  • Response to Robert Karl Stonjek on Chemosynthesis
    ... This "appears" to possibly be examples of "chemosynthetic" organisms ... view is chemosynthesis preceded photosynthesis and we would not be ... alive today as an organism had it not been for chemosynthesis although ... PRODUCTION?Dissolution of Silurian-Devonian aquifer in the Lake Huron ...
    (sci.bio.evolution)
  • Re: Trees of Life
    ... Photosynthesis and chemosynthesis are not means of life developing. ... They are terms used to describe how organisms extract energy from ...
    (talk.origins)
  • Re: Trees of Life
    ... It seems to me that the first forms of life, by definition, had to be ... As far as I can see, chemosynthesis is the more likely of the two as most ... photosynthesis probably originated in the oceans. ... That is why plants get their own kingdom. ...
    (talk.origins)
  • Re: Trees of Life
    ... Photosynthesis and chemosynthesis are not means of life developing. ... They are terms used to describe how organisms extract energy from ...
    (talk.origins)