types of organization
Prof. Dov Por
dovpor at NETVISION.NET.IL
Mon Feb 7 17:17:22 CST 2000
It is clear what are our very disagreeing positions. We cannot carry-out
this discussion on taxacom and at the expense of the patience of
everybody.I am ready to continue it in a more discrete form!
Still I wonder how flat is you idea of evolution. Are we specialised
descendants of a generalized flatworm?
Haeckel transposed into ontogeny the "Scala Naturae" of Aristo and of
Lamarck. Evolution was linear, head-to- tail: in our ontogeny we pass the
unicell stage followed by the coelenterate(the gastrula) , the amphioxus (th
neurula) the fish the amphibian, the reptile , etc. Haeckelian ontogenesis
repeats a linear phylogenesis.
I mentioned the irreversibility of the metazoan level in order to show that
evolution to higher levels of organization is irreversible , a truly
From: John Grehan <jrg13 at PSU.EDU>
To: TAXACOM at USOBI.ORG <TAXACOM at USOBI.ORG>
Date: 07 February 2000 15:17
Subject: types of organization
>>By the same logic we could say that we are just another way of packing the
>>nucleotides, or different expressions of the atom carbon.
> Evolution , in
>>the very literally sense means a qualitative change.
>By the recombination there has been a change from (relatively) generalized
>to specialized descendants.
>>By the way, old Haeckel would be very happy to see you considering us a
>>kind of fish,amphibian, reptile, etc. Do I sense here a "ladder of life"?
>What do you mean by "ladder of life"?
>>Just as mitochondria are not comparable to free-living bacteria anymore,
>>are our cells.
>Not the same Iwould agree, but they are comparable to some.
> Even the single cell, our mother ovule, or even the legions
>>of spermatozoans, are unable to live independently.
>True. Again, by the concept of types of organization they are not identical
>with free-living single cells, but they share these qualities with many
>parasitic single cells (i.e. disease organisms).
>By the way, I don't know
>>of any metazoan which "returned" to protozoan life.
>What is being compared here? I do not recall making an assertion of this
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