wirelessguru1 Wrote:
-------------------------------------------------------
> > No. You keep trying to make "evolution"
> identical to speciation.
> > This is too limiting evolution includes
> speciation but is not limited to it.
>
> No, my point here is to explore the other aspect
> of "evolution" which I call "degeneration", or the
> population getting dumber and dumber and then,
> potentially getting extinct, due to sudden
> environmental changes.
>
> I believe that the evidence shows that this is
> what actually happens.
>
> > We were discussing the formation of species.
> If you get two populations that
> > periodically exchange genes you will not get
> them to be different enough to no
> > longer be able to reproduce and thus become
> separate species.
>
> but, degeneration can then occur within the same
> species!
>
> > This does not mean that each population will
> remain unchanged.
>
> indeed, it seems like the gneral trend, therefore,
> based on a society is degeneration...
>
> > They will each continue to change their gene
> pools through the variety of
> > mechanisms that I specified above. Remember
> microevolution includes
> > processes UP TO and including speciation.
>
> Maybe, or maybe they are actually just
> degenerating in certain ways! The evidence shows
> that degenerative behavior seems more and
> pervasive!!!
>
> > If it happens that the environment changes
> and the PREEXISTING genetic
> > variety is not able to respond then the
> organisms will die. Millions of
> > species have become extinct over time. it is
> not all one way.
>
> EXACTLY, degeneration can win even without
> complete extinction as the population gets dumber
> and dumber and more dependent on external
> processes, machines and Governments to solve their
> problems and even to ACTUALLY feed them!!!
>
>

SNIP repetitious stuff

Dear Wireless

I'll just respond to this post because your subsequent posts are mostly repetitions of the same basic idea. The fundamental problem is that you are injecting a political view point into the discussion by a fundamentally flawed mixture of apples and oranges. Organic evolution applies to all species (not just humans)-- did dinosaurs become extinct because they got dumber? They were pretty dumb to start with if you look at the ratio of their brain size to their body size :-). Are salmons getting dumber because they can no longer spawn due to the existence of dams in the rivers they used to spawn in?

This is a good spot to put in some general comments that will apply to the beginning topic of this thread. We can distinguish 3 levels of adaptation to stress-- I will use high altitude and cold as examples of environmental stress.

1) level 1 Genetic adaptation(most fundamental and slowest-- requires changes in the genome. For example, humans at high altitude and cold might evolve fur like polar bears or a new way of handling low oxygen levels. This would take a long long time and Tibetans, or Quechuas have not been in their localities long enough. Actually what HAS evolved genetically are common human mechanisms to adapt to these stresses physiologically.

2) Level 2 Physiological responses (genetically based and potentially available to most humans-- there are fast physiological responses and developmental physiological responses which may take from months to a lifetime or more).
Examples of fast physiological responses-- to cold 1) shivering muscles moving generate heat, 2) vasoconstriction blood vessels near the surface of the body contract and minimize the heat loss from the warm blood to the exterior (just to show that adaptations are not always great-- if this goes on too long you get frostbite and or gangrene). To high altitudes- you immediately start to pant to get more oxygen into the sytem.

Slower physiological responses-- to cold 1) people who live in colder regions have a higher basal metabolism so that the body at rest produces more heat, 2) Quechuas and Sherpas do not shut down the blood flow to their hands, feet, and ears. To high altitudes-- 1) after a couple of weeks humans start to produce red blood cells to get a higher percentage and be able to carry more oxygen-- this is why athletes train in Colorado before the Olympics. It is also how illegal blood-doping works, The Quechua and Sherpas have an even higher proportion of red blood cells due to living all their life at altitude. 2) Quechuas are very short people with very large chests and lungs, i.e to get more air per inhalation and also to need less because of small body size. The latter adaptations take a lifetime and may get passed on (small mothers make small babies because only small babies can get by with the lesser amount of oxygen that is making it through the umbilical cord, etc. etc. The point is that none of these responses required a new mutation or genetic change. These responses were available within the range of the human physiological toolkit.


3) level 3 Cultural responses (The crowning glory of being human, extremely flexible and potentially rapid. ) Here your imagination can go wild. Cultural Responses to cold-- light a fire, build an igloo, make warm clothes, develop furnaces and houses, eat food with lots of fat, etc. etc. A couple of interesting responses by Quechuas is that they sleep in a pile to exchange body warmth and that they chew coca leaves to make the environment more tolerable and apparently to improve the metabolism of glucose. Responses to high altitude-- carry oxygen bottles, take pregnant women down to sea level in order to avoid spontaneous abortions (this is what the Spanish who lived in places like Lima used to do.)

When humans arrived the entire evolution game changed. Culture is what has allowed humans to settle all the world and dominate all the other species in the blink of a geologic eye. Culture allows us to (some extent) resist and/or change the environment we live in. The human brain (and language, which is essential to culture) are the key genetic adaptations that we possess. what we have evolved to stretch a metaphor is not a getting a fish but learning how to fish. We have evolved a machine that makes adaptations. Now to Wireless's point.

The rise and fall of civilizations has nothing to do with organic evolution. This is a question of culture and has to be dealt with at that level-- you are doing comparisons at different philosophical levels. BTW your claim that we (or whoever) is geting dumber and dumber is standard rightwing propaganda (pardon the political intrusion). What is neede in not an assertion but evidence and you havve not provided any. It should be a different tread anyway.

Bernard