wrote in message
news:bamr9p$1o06$1{at}darwin.ediacara.org...
> I contend that due to my model, no species 'evolves' unless
> they are forced to adapt to harsh changes - thus
>
> As environmental adaptation increases:
>    directional and diversifying selection decreases AND
>    stabilizing selection increases.
>     (and vice versa)
>
> So I contend that the brain development in hominids was due
> to the harsh environmental weather at the time:
> "The fourfold expansion of the hominid brain did not start
> until the ice ages began, 2.5 million years ago.
> Ice cores from Greenland show frequent abrupt cooling
> episodes superimposed on the more stately rhythms of ice advance
> and retreat. Entire forests disappeared within several decades
> because of drastic drops in temperature and rainfall. The
> warm rains returned with equal suddenness several centuries
> later.
> The evolution of anatomical adaptations in the hominids could not
> have kept pace with these abrupt climate changes, which would
> have occurred within the lifetime of single individuals.
> Still, these environmental fluctuations could have promoted the
> incremental accumulation of mental abilities that conferred
> greater behavioral flexibility." W. H. Calvin.
>
> I contend that more than any single advantage hominids
> possessed - it was the drive of an unforgiving environment
> that pushed human brain development.
>
> Comment?
>

Yes, I completely agree with you and Calvin on this. As I recall, hasn't
Calvin also linked the ability for homo sap. to grow big
brains to juvenilization, i.e., babies being born with a premature
appearance (e.g., small brains at birth which lessens the chance
of killing the mother) further linked to the resultant selective pressure
for slower growth rates to puberty and corresponding
longer periods of child care necessitated thereby? I recall that Calvin
further posits that the development of the larger brain in
homo sap. was facilitated by developing throwing skills, which honed the
unique organizational development of the mind.

> Tom Hendricks
> The main points of my hypothesis are:
> 1. How life began as a reaction to the sun/UV and the thermal cycle of
> hot-dry-sun/cold-wet-night. Then continued as an energy moderator with
modification
> through descent.
> 2.  The Four Options and how they relate to thermodynamics, biological
> classification, the first cell, modification on all levels,
psychological behavior
> of individuals and groups, inner conflicts and a therapy of resolving them, etc.
> 3. Model showing relationship between adaptation fitness and natural
> selection. How it supports punctuated equilibrium and the 'slope and
plateau' model
> etc.
>
> Tom Hendricks, Hendricks Health Theory
> text files at
> 
HREF="http://www.ediacara.or" target="new">http://www.ediacara.or">http://www.ediacara.org/~josh/hendricks.html">http://www.ediacara.or
> g/~josh/hendricks.html
> (text #10 has a pretty up to date summary)
>
>
>
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