Re: Some help with "a lack of dinosaurs post", please

"I see you also don't know how to quote. You really need to learn that
too, to provide context. Your newsreader should do this automatically.
See how I automatically put your text before mine, marked off by >?"

I may still have trouble with that, so bear with me, my friend!

"No. Catastrophism and gradualism are both important in evolution. Mass
extinctions are obviously catastrophic."

So you admit Mass Extinctions from global catastrophies, but still hold
that gradualism is the "heartbeat" of the origin of the earth and life
upon it?

"Now there you're wrong. Bone beds are not evidence of extinction, but
of
smaller catastrophes, like a bunch of animals killed trying to cross a
river in flood, as happens every year to wildebeest herds in Africa. Or

it might just be a collection in some sand bar of animals killed at
different times and places, but washed by the river into a common spot.

Don't confuse that with mass extinction."

If a meteor struck the earth and killed 50% of life upon it, you don't
think that bone beds could result? I'm certain that "local
catastrophies" could be explanations for some bone beds for sure....
Are you now saying that mass extinction occurs and leaves no trace?
"Gradualism" in regards to the fossil record is a pleasant little
passion play of the miracle of Johnny Dinosaur dying on the bank of the
prehistoric river, and by mere happenstance he gets covered in silt and
by the rarest of rare phenomena gets fossilized for Joe Bonehead to dig
up 200 million years later. That's the "story of fossils" that our kids
read in their "Big Book of Dinosaurs". Reality shows that where you
find one skeleton, many more of the same species is in the area.
Coelophysis fossils at Ghost ranch are a prime example.

Fossil "rarity" as an excuse to dismiss the lack of smooth transitional
species between major animal families doesn't hold much water with me.
We have fossilized Dino-***, eggshells, footprints, and "collections
in some sand bar of animals killed at different times and places, but
washed by the river into a common spot" that we can study. The "age" of
the fossil finds are so ambiguous.... it is so easy to say + or - 10
million years or more and not have it even be questioned.

"Punctuated equilibrium actually has nothing to do with catastrophism,
so
your question is quite confused. PE is not particularly popular with
most evolutionary biologists. "

So you have no argument with my comment that from the mass extinction
of the dinosaurs 65 Million years ago, we have a new stage from which
all modern species arose. (I won't split hairs on definition of
"species" so just take it as an obviously separate type of critter).
From the event that killed off the dinosaurs, changed the climate so
dramatically that 50% of all species were killed. Of course, this is
after 251 million years ago - at the Permian-Triassic transition when
about 95% of all marine species went extinct. This catastrophe was
Earth's worst mass extinction, killing 53% of marine families, 84% of
marine genera, and an estimated 70% of land species (including plants,
insects, and vertebrate animals.)


"You have a basic misunderstanding of evolution. No single mutation
brings about either wings or a horn on the head. Instead, many
mutations
of small effect, each one advantageous and so preserved by selection,
can result in a wing or a horn. Mutations introduce variation,
selection
winnows them. Both are necessary. "

I think you have a basic misunderstanding of my comment. You'll find i
make sarcastic comments on occassion that obviously you must have
missed. I wasn't suggesting that a "single mutation" would bring about
wings or horns, but that there is nothing that says that a creature
can't "evolve" anything in particular.... that one path of variation
(toward the devolpment of wings) is not dependant upon any other (i.e.
horns).

Can you say it is "impossible" for Humans to evolve wings some day?
Could a horse not someday evolve into an unicorn? Evolution doesn't say
it couldn't, given "enough time". There are also MANY animal "features"
that scientists ask "what is the advantage" or "why did this feature or
behavior "evolve"" because evolve it MUST have.


"Not new genes, necessarily. Variations on existing genes (or other
genetic elements)."

Uh....EVERY gene, and every "genetic element" had to at one time NOT be
in existance, and then, somehow, exist. Unless you are saying that
creature groups were created with a set of inherant, yet variable,
genes that allow them to live and prosper, but also ADAPT to the
changes in environment... But then you'd be a pariah to suggest such an
insane heresy.

"Environment doesn't drive mutation. It just drives
selection. Things that are neutral or deleterious in one environment
are
advantageous in another. So let's suppose that it would, in the late
Cretaceous, be disadvantageous for a mammal to get bigger, because then

it would be harder to hide from predatory dinosaurs, or would bring it
into competition with dinosaurs in some other way. Remove the
dinosaurs,
and suddently the disadvantage disappears. Mutations that increase size

may be positively advantageous, since they help the animal gain more of

the suddenly more plentiful resources. So you get size increases in
multiple species. Simple, really."

I have absolutely no argument with that general comment at all! Natural
selection is obviously a way for creatures to adapt and move ahead in
the world. Take, for instance, dwarfism. Isolated on Islands, many
creatures that were once large, over time, become small (mammoths are
one example) when faced with restricted diet and range; and other,
smaller creatures tend to grow gigantic (galopogos tortoises) when
given the opportunity of no predation.

But that is just examples of variation within an animal group. change
the environment and they would change again, but the mammoth is still a
mammoth, and the tortoise is still a tortoise. The adapt, or they die
out. You suggest that not only do they get bigger, but split off into
completely new and novel orders of mammals....each new species a
"common anscestor" to other completely new and novel orders and
families before suffering their own extinction.

Special variation to adapt to change in environment does not prove that
the variation will continue on to add completely new genetic
information that could eventually turn a cow into a whale.


"The pool of existing genetic variation will suffice for a surprising
amount of adaptation. "

Again, we're looking at "pre-existing gene pool".... the gene pool had
to either "evolve" or be created. It can't evolve without having been
"selected" and why would it be "selected" unless it is a "useful" gene?

"New mutations will replenish that pool over time. "

"replenish"? Are you now saying that the gene-pool is a holding ground
of mutated genes which carry all sorts of morphological and chemical
and behavioral cues... untapped until future adaptions are needed?

"And in fact, mutation rates are fast enough to account for the
observed
rate of change in fossils. If anything, the problem is explaining why
the observed rate is so slow, orders of magnitude slower than selection

is observed to operate in nature. "

I think we've again separated genetic addition from genetic selection.
Mutation rates are fast enough to account for the rate of change in
species? What mutation rate? How often is completely new genetic
material added? The observed selection in nature you mention.... have
we yet seen a completely new family of unbefore known animals from
which we can trace their common anscestor? Or are you talking about
mosquitoes in france subways or 12 winged fruit flies? Variation and
speciation within a type of animal is evidence of pre-existing genetic
material, not previously nonexistant genes popping up.



"Obviously immune systems and pathogens have to evolve together. Which
they clearly did. "

Did they? clearly? Such a statement is akin to answering "which came
first, the Chicken or the Egg" and saying "Obviously Both". "obviously"
is a strong statement, but perhaps I'm not smart enough to always catch
the "obvious". Did pathogens and immune systems evolve from the same
"common anscestor system"? I'm not sure why it is obvious that they had
to evolve together... unless that is the best answer besides "I don't
know".

.

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