Mr J.M. Ottevanger (J.Ottevanger@LIVERPOOL.AC.UK)
Sun, 12 Feb 1995 12:10:21 +0000

> I cocked this up before so I'll send it again in case it's of interest:
> On the subject of Calvin, as you, James B and the other geezer are, his idea
> fits well with what Elizabeth Vrba has been talking about for a while, that is ,
> the influence of the "environment" upon speciation events. I don't take
> everything she says quite as it stands, but the thesis that in environmental
> stasis there is little drive to adapt, and that therefore changes are the main
> driving force of evolution is sensible enough. The objection that climate
> fluctuations could not have been a factor in the evolution of the human brain
> because it would have caused simlar events to happen in other species is a
> nonsense, since species are bound in their potential adaptations by phylogenetic
> constraints and one cannot expect each organism to respond to a pressure in the
> same way. To be corny about it, one would not expect,for example, a plant
> lineage to respond to a drying out of the climate in the same way as a mammal.
> They are likely, perhaps, to play to their strong points: plants becoming more
> dessication- and fire-resistant, bovids becoming better at processing their
> food, hominoids better at procuring it. Reliance on intelligence may light a
> fire that becomes a force in its own right. As to whether that first push comes
> from climate change or something else, who knows for sure?
> Jeremy.
> In the last mail Scott Holmes said:
> >
> > I mention this because I am very much intrigued by William Calvin's
> > theory of an "evolutionary pump", ie ice age fluctuations. Regardless
> > of the location on earth of the main human population, fluctuations in
> > ice extent had an effect on their environments thus changing the rules. I
> > think it would follow that those individuals most capable of adapting to
> > the environmental (context) changes would be most successful in those
> > activities that produce progeny. These activities would include the whole
> > suite of topics discussed on this list: tool making, social development etc.
> >
> > Personally, I haven't a clue as to which bootstraped which, brain size or
> > intelligence. It would seem, though, that Necessity IS the Mother of Inventio
> n.
> >
> >
> >
> > ----------- There are more things in heaven and earth, Horatio, --------------
> --
> > Scott Holmes <> Informix 4GL Application
> s
> > ---------------- Than are dreamt of in your philosophy. ----------------------
> --
> >