in reply to Which came first?
?->Big_Bang->Energy/Light/Gravity<->Elementary_Particles->Supernovae<->Stardust (carbon, iron, silicates etc)->Organic_Chemistry (amino acids etc)->DNA<->RNA->Protein (enzymes etc)<->Cell/Protista->Egg+Sperm<->Multicellular_Organisms (chicks et al.)
There are feed back loops in this chain (web, actually) but from an evolutionary 'historic' perspective the 'egg' (and sperm) preceded the cellular aggregates that evolved as organisms to utilize the egg/sperm as their mechanism for sexual reproduction. Examples are plenty, for instance in planctonic algae.
allan
There are feed back loops in this chain (web, actually) but from an evolutionary 'historic' perspective the 'egg' (and sperm) preceded the cellular aggregates that evolved as organisms to utilize the egg/sperm as their mechanism for sexual reproduction. Examples are plenty, for instance in planctonic algae.
allan
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Re^2: Which came first?
by shmem (Chancellor) on May 05, 2008 at 15:32 UTC | |
by ady (Deacon) on May 06, 2008 at 19:50 UTC | |
by ady (Deacon) on May 06, 2008 at 19:52 UTC | |
by shmem (Chancellor) on May 06, 2008 at 23:15 UTC | |
by ady (Deacon) on May 07, 2008 at 05:21 UTC |
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