[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Triassic protofeathers and fake-heads



Ken Kinman (kinman@hotmail.com) wrote:

<It seems to me that there is a clear trend among land vertebrates. 
Amphibians have pretty primitive brains and are pretty slow except for
their tongues. Reptiles were more advanced in many ways, but it wasn't
until the Mesozoic that the endothermy thing really kicked in.  Had some
pretty brainy and fast dinosaurs, but that unfortunately didn't help them
survive the K-T extinction. Birds and mammals with their endothermy had a
running start when the Cenozoic began, but they certainly weren't as
brainy and coordinated in the Paleocene or Eocene as are modern carnivores
or their fast-running prey. So I guess I would have to say that I do
believe there is a trend toward increasing speed and intelligence in the
history of predators and their prey.

 The struggle for survival is a stress that inherently results in 
improvements (I'm trying to avoid the word "progress").>

  The struggle to compete and survive in a world where your prey is fast
and your predator as fast is what Bakker termed the Mesozoic Arms Race.
While esentially true, there are variables that not not apply to all
features that leads doubt to their coherence in a single paradigm. The
smarter cats still fail to catch the more stupid gazelles. And more often
than not, the gazelles aren't getting any brainier. Instead, agility and
speed is the quotient. This is true for most _terrestrial_ predator-prey
relationships. If the prey has a tendency to be big, this then becomes
emphasized, and armament and thick skin is employed, often at the expense
of speed. Only then do brains get adapted, as in the elephant ... but for
some reason, no one expounds on the cranial prowess of the rhinoceros.
antelope armament is typically interspecific, as in cervoids. Brains are
the rule, though, in armoreal animals. They either develop flee techniques
and stay dumb, or develop brains, coordination, and communication
abilities. Birds had the advantage of flight long before their brains
reached modern levels ... but look at the earliest birds, still dumb as
oxen; the smartest birds are the _clever_ ones, the users: passerines like
crows, or parrots. And there's primates, more arboreal animals like myself
(I hate heights, but I love trees), who develope these positively gigantic
crania compared to out bodies and remarkable sensory capabilities that
emphasizes vision and hearing ... oh, and voice. As in birds. In these
animals, except for secondary reversals -- humans and ratites to the
ground, penguins in the water -- the normal rules of the arms race do not
apply.

  A predator, for one thing, fears only a larger predator, but never does
a predator develop a mechanism to which to counteract another predator: it
is unneccessary. Predator-on-predator events are so rare and so negligible
that they do not require an evolutionary cost to expend on devlopment
_against_. Thus, Kinman's "fake-head" is not ecologically sound.

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

__________________________________________________
Do You Yahoo!?
Yahoo! Sports - Coverage of the 2002 Olympic Games
http://sports.yahoo.com