From: Scott Chase (email@example.com)
Date: Thu 03 Nov 2005 - 15:31:27 GMT
--- Dace <firstname.lastname@example.org> wrote:
> It is an established fact that development of
> embryos cannot take place
> without genes. Necessity and sufficiency.
Depends on how you word it. Some species' embryos can develop for a little while without having a nucleus
(ie- zygotic gene activity), but I think this has much to do with maternal products getting the embryo to a certain point before the nucleus kicks into gear (see Brian Hall's _Evolutionary Developmental Biology_ 2nd ed pbk, p.116). Thus to a very limited extent we could say development takes place sans embryonic gene activity, but maternal gene products would take up the slack. This makes necessity slightly problematic in a very limited context.
Genes are not sufficient for development. What's a
zygotic genome going to do without a...ummm...zygote.
And what about nutrients? Aren't proteins, carbs etc
important to development? Aren't vitamin deficiencies
bad for a developing fetus? Malnutrition surely can't
be good. Genes can't do much without a surrounding
cell and without food (such as a yolk) and water.
Would calcium be important for bone growth? Just
asking. If the sun were to disappear, wouldn't this
have a negative effect on embryonic development of
> The investigations of the last century have enabled
> us to understand many
> mechanistic functions of the body, including genetic
> mechanisms. But this
> cannot by itself establish that organisms are
> fundamentally mechanical. A
> theory that can't account for self-determination is
> not a complete theory of
> life. This applies to the self-determination of
> species (evolution) as much
> as individuals.
Self-determination? Why are you taking something from human-centric political and or moral philosophy and applying it to realms where it's not appropriate? How can a plant express self-determination like a nation
(in the Wilsonian sense) or a person with a cortical organization complex enough to formulate and understand the concept of volition? How can a species
(an aggregate of individuals) express self-determination? A behavioral isolating mechanism doesn't come close, since neither the individual nor the aggregate of individuals biologists place it within are "aware" that they are determining anything. An isolating mechanism arises by chance and keeps individuals of distinct groups from interbreeding on average. This is a byproduct of a genetic, structural, or behavioral incompatibility arising over time when two groups are geographically isolated, not a species saying: "You know I'm going to go out into this world and stake a claim for me and my kind" like the legendary architects of some struggling nation.
__________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com
This was distributed via the memetics list associated with the
Journal of Memetics - Evolutionary Models of Information Transmission
For information about the journal and the list (e.g. unsubscribing)
This archive was generated by hypermail 2.1.5 : Thu 03 Nov 2005 - 15:51:58 GMT