On Tue, 02 May 2000 11:38:11 -0500, Susan Brassfield wrote:
[...]
SB>Stephen Jones quoted:
>SJ>...virtually everyone agrees that the Cambrian started almost
>>exactly 543 million years ago and, even more startling, that all but one of
>>the phyla in the fossil record appeared within the first 5 million to 10
>>million years. "We now know how fast fast is," grins Bowring. "And what I
>>like to ask my biologist friends is, How fast can evolution get before they
>>start feeling uncomfortable?" (Nash J.M., "When Life Exploded", Time,
>>December 4, 1995, p74.
>http://www.time.com/time/magazine/archive/1995/951204/cover.html
SB>Wonderful article. I recommend everyone read all of it. Here's another
>quote just a few paragraphs above Stephen's tidbit:
>
>"What could possibly have powered such a radical advance? Was it something
>in the organisms
>themselves or the environment in which they lived? Today an unprecedented
>effort to answer
>these questions is under way. Geologists and geochemists are reconstructing
>the Precambrian
>planet, looking for changes in the atmosphere and ocean that might have put
>evolution into
>sudden overdrive. Developmental biologists are teasing apart the genetic
>toolbox needed to
>assemble animals as disparate as worms and flies, mice and fish. And
>paleontologists are
>exploring deeper reaches of the fossil record, searching for organisms that
>might have primed
>the evolutionary pump. "We're getting data," says Harvard University
>paleontologist Andrew
>Knoll, "almost faster than we can digest it." "
Maybe Susan would also like this quote by the same author in an earlier
issue of TIME on how hard it is to change the samer "genetic toolbox":
"The drawback for scientists is that nature's shrewd economy conceals
enormous complexity. Researchers are finding evidence that the Hox
genes and the non-Hox homeobox genes are not independent agents but
members of vast genetic networks that connect hundreds, perhaps
thousands, of other genes. Change one component, and myriad others
will change as well-and not necessarily for the better. Thus dreams
of tinkering with nature's toolbox to bring to life what scientists
call a "hopeful monster"-such as a fish with feet-are likely to remain
elusive. Scientists, as Duboule observes, are still far from
reproducing in a laboratory the biochemical artistry that nature has
taken millions of years to accomplish." (Nash J.M., "Where Do Toes
Come From?," TIME, August 7,1995, p.69.
http://www.time.com/time/magazine/archive/1995/950731/950731.science.html)
I have no problem with sudden change by hox genes. My problem is
how could a `blind watchmaker' ever do it, when even human intelligent
designers can't? To me this is good evidence for intervention/guidance
by a supernatural Intelligent Designer.
Steve
--------------------------------------------------------------------------
"Aviation engineers look wide envy on birds and especially insects. Their
flapping wings lift and propel them far more efficiently than the fixed wings
of aircraft. One reason is their ability to exploit the subtleties of stalling.
If the angle of attack of a wing is increased, it ultimately stalls, with sudden
disastrous loss of lift. No fixed-wing aircraft dare risk stalling But an insect
with oscillating wings can exploit an intriguing loophole in the laws of
aerodynamics. Accelerated at a high angle of attack into the stalling
regime, a wing takes a short while to stall. And until it does, it generates
enormous lift. By speeding into stall and out again at each flap, an insect
wing develops amazingly high average lift. (Jones D., "The insect plane,"
Nature, Vol. 400, 5 August 1999, p.513).
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
--------------------------------------------------------------------------
--------------------------------------------------------------------------
"Aviation engineers look wide envy on birds and especially insects. Their
flapping wings lift and propel them far more efficiently than the fixed wings
of aircraft. One reason is their ability to exploit the subtleties of stalling.
If the angle of attack of a wing is increased, it ultimately stalls, with sudden
disastrous loss of lift. No fixed-wing aircraft dare risk stalling But an insect
with oscillating wings can exploit an intriguing loophole in the laws of
aerodynamics. Accelerated at a high angle of attack into the stalling
regime, a wing takes a short while to stall. And until it does, it generates
enormous lift. By speeding into stall and out again at each flap, an insect
wing develops amazingly high average lift. (Jones D., "The insect plane,"
Nature, Vol. 400, 5 August 1999, p.513).
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
--------------------------------------------------------------------------
This archive was generated by hypermail 2b29 : Tue May 02 2000 - 18:00:03 EDT