[extropy-chat] Evolution of the Head (was Re: Crows Invent Machine)

[The Avantguardian]

--- spike <spike66 at comcast.net> wrote:
>  Why did one species of dinosaur end
> up with the brains?  The
> other species seemed to do fine without much in the
> old cranium.

Actually the raptors were not a single species but
many different ones. The ones in Jurassic Park were
actually Deinonychus a related but separate genus. The
ones in JP were actually small compared to Utahraptors
which were 14 feet long and stood 8 ft high. All these
dinosaurs were characterized by being fleet hollow
boned predators. They also hunted in packs which was
unusual for dinosaurs.  
 
> My notion is that ecosystems should produce
> remarkably smart species, such
> as gulls and crows.  Consider lions: they do some
> behaviors that one would
> think would require some form of communication and
> organization, such as
> lining up spaced at appropriate intervals, singling
> out some hapless beast
> from the herd, then tag team chasing it until it
> drops.  Yet no one has ever
> seen any cat roaring instructions.  That's a trick! 
> HOw do they know to do
> that?

Interesting question. I am willing to bet it is thru
eye contact as roaring instructions would give away
the ambush. I think that eye contact is one of the
ways that prey animals are selected as well. If you
watch National Geographic it seems that every
wildebeest in the herd rolls its eyes when there is a
lion looking at it, kind of like when a human boss is
looking for a volunteer for an unpleasant task. 
 
> I find this interesting because it demonstrates the
> group survival value of
> intelligence.  The crows and lions might help
> explain why humans evolved
> these wildly oversized heads, which is something I
> have pondered for years.

Well it has much to do with the evolution of the head
in the first place. This process is called
encephalization and it has been studied. Heads do not
appear in the fossil record or in existing genera
until the creature starts to become motile. Motility
introduces assymterical body development. Since there
is a survival advantage to having sensory organs in
the direction one is moving as opposed to other
directions, one finds that sensory organs and the
nervous systems needed to process those senses tend to
cluster at the front of a critter.

Intelligence is a just a further layer of complication
to this. In general predators are smarter than
herbovores. This is because in addition to teh simple
problem of looking where they are going, they have to
be able to plot intercept courses to their prey. Thus
predators have evolved to unconsciously solve analog
calculus problems in their head. Thus by the time you
get to sprinting pouncing ambush predators like the
cats, you have quite a bit of intelligence.

Birds, because of the very fast speeds and fully 3
dimensional nature of flight HAVE to be intelligent
because they not only have to watch for obstacles and
prey but other birds as well. They also have to have a
greater appreciation for gravity, wind, and other
things that most terrestrial animals can take for
granted.

Primates take it to the next level. The most primitive
primates are arboreal. They have to be able to leap
from branch to branch and if they miss that branch
they are in a world of hurt. So they have to have many
of the same processing power as birds. Apes take it
even farther. They can throw things like rocks and
feces at targets like an irksome predator that comes
too close. 

To do this requires an additional layer of abstraction
of time and space. Not just for themselves and their
target but for the thing that they are throwing. 

There was an article in Scientific American a few
years back where somebody had a theory that the
development of symbolic language in people was derived
from the ability to abstract the trajectories of
thrown missiles. I think (s)he was pretty close to the
truth with that one.

 In a way, the need to see into the future in more and
more complex detail starting with simple movement
around obstacles. Then to catching prey while running
or hurtling thru the air. Then catching prey, finding
mates, and avoiding obstacles and predators while
flying. And finally being able to abstract oneself
into an inanimate object and unconsciously calculate
the ballistic trajectory necessary to nail Professor
Frink with a turd or the antelope with a spear all
contributed to big headedness. :)


Stuart LaForge
alt email: stuart"AT"ucla.edu

"A human being is part of the whole called by us 'the universe,' a part limited in time and space. He experiences himself, his thoughts and feelings, as something separate from the rest - a kind of optical delusion of consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening the circle of understanding and compassion to embrace all living creatures and the whole of nature in its beauty."

-St. Einstein

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