Re: done deal, cope re: In spite of dinosaurs evolving to birds being


"Kent Paul Dolan" <xanthian@xxxxxxxx> wrote in message
news:h1pfku$tl3$1@xxxxxxxxxxxxxxxxxxxx
rmj wrote:

And let's note that the controversy, such as it
is, is not over whether there is a tree of life,
but over just what shape the tree of life takes.

There should be a conversation among scientists on
this subject.

There has been, You are experiencing the received
wisdom _after_ that widespread discussion is a done
deal.

There's an example of a closed mind.


If you don't like that reality, well, that is a
personal problem you have, nor a problem science
has.

If science has a bias towards the data, then that would be a problem for it.

Cope.

That is what I am doing.


The common DNA code sequences and DNA operating
mechanisms among _all_ living species guarantees
with immense likelihood that they share _a_ common
ancestor.

"Immense likelihood." Wow! I guess I better accept it as true! Wait a sec,
where's the math?


This is an example of how scientists view
information with bias.

No, this is just you creationists attempting to call
into dispute over, and over, and over, and over,
questions long settled by science, simply because
you are in thrall to a deranged agenda that requires
you to reject biological evolution in toto, and
absolutely mindlessly, as well.

Think you have me pegged? Ego uber alles.


Despite your obstructionist training in the matter,
it is _not_ the case that each and every creationist
has a right separately to be led by the hand (or the
nose) through the entire basis of evidence for the
theory of evolution, while misbehaving with
intellectually dishonest stalling tactics every step
of the way.

And where have I been done that even once?


Sooner or later, you're going to be abandoned to
find and read the technical literature for
yourselves, simply because scientists and interested
well educated amateurs supporting the ToE have
better thiings to do with their lives than drag you
in your unending droves through your self-inflicted
ignorance.

Watch out, for if that happens the creationists will claim victory, and the
populace by and large will perceive scientists as pseudo-intellectual elite
fabricating a false reality. But on second thought, I guess, you personally
have had your evidence shot down by some cretin of a creationist and now are
gun shy.


One can only hope that the resulting shocks to your
systems of being required to think coherently and
honestly proves fatal -- the human species can well
do with a lot fewer idiots in its breeding cohort.

Boy, you do love the ad hominems.

A little imagination and one can see the
possibilities of multiple origins that over time
exchanged molecules (dna rna) and so now appear to
have been a single tree.

To be able to exchange DNA/RNA, those organisms
would have had to have a common ancestor from which
the mechanisms of DNA/RNA functionality were
inherited, so again, your thinking is muddled.

No mechanism needed; just a primitive structure. See my reply to Harshman.


Just because later descendents of that LCA exchanged
genetic matter via horizontal transfer, making the
"tree" more of a sparsely interconnected lattice,
especially down toward its roots as seen from
"here", doesn't mean that there were "multiple
origins"; it just means that you are deeply and
profoundly confused about what it means to be an
original living organism.

Well look at that, you agree with my argument. Trillions of roots coming
together to produce a tree. The origins of these roots would be the early
poor replicators, a small fraction of which (and yet possibly numerous)
became better at replicating. And, I argue, would randomly exchange
information (some coherent, most not).


It is an assumption that aeons ago a single
replicator arose

It is more than "an assumption", it is a working
assumption of biological science (much like the
Riemann hypothesis is a working assumption of
mathematics despite being unproven, simply because
no falsifying cases have been found in "decades if
not centuries") because all the observations we have
now support that understanding of the abiogenesis
event.

Science has no understanding of the abiogenesis event, rather there is an
abundance of generalized speculations. RNA first? No, membrane first. No
proteins must have been first. Can't do nuttin widout sugars, etc.


What we don't have, simply because the details are
obscured by time, and what we very likely never will
have, because we may well come up in the laboratory
with several alternative mechanisms all of which
"work", without any way at this long remove to
decide _which_ of them _did_ work, or whether the
actual event was something not yet envisioned by
researchers.

That is the distant future. You seem to think science is close to finding a
plausible mechanism for abiogenesis.


So, probably the best science will _ever_ be able to
do, is to prove that abiogenesis is easily possible,
not pin down exactly which version among versions
easily possible, was the one that happened here on
earth.

that proved to be so much better at survival that
all life evolved from it.

Your train of thought ran off the rails there at "so
much better", since you didn't finish the thought to
say "so much better" than _what_.

Than a slight advantage. One can argue for the power of a slight advantage
in survival/reproduction after the rise of protocells that can control the
flow of molecules across the membrane, as well as having a reliable process
of replication. Before these exist, a slight advantage is immensely unlikely
to drive one replicator to become the single ancestor as it starves out all
its competitors.


Your train of thought _stays_ off the rails:

No, you haven't found the track I'm on.


A point mutation would very likely only provide a
small advantage and such would occur often in a
pre-cell replicators since DNA repliction would be
a relatively crude process.

You make the unsupported assumption that the first
replicators utilized DNA. This is so incredibly
unlikely as to be instantly dismissable from
consideration. The first replicators would need to
be molecules built of at most dozens of atoms, not
of tens of thousands of atoms.


Of course I do not know what the first replicators were. I am a little
farther along, closer to the protocell.
But without RNA or DNA I cannot see how replication can occur. I am aware of
some self-replicating molecules synthesized in the lab, but I have seen no
arguement on how they can evolve into something complex.

The result would be a plethora of variation.

The first replicators, being naked to the broth in
which they arose, would be both very vulnerable to
variation, at the "impact by surrounding atoms"
level, and also brittle with respect to variation,
lacking self-repair mechanisms, thus surviving only
by replicating unmodified faster than individuals
were being incapacitated by variaton, so that
getting from "first replicator" to "first replicator
rebust to minor variation" was likely to have been a
process evolved with great wastage over a huge
number of generations.

I see this picture and ask, why do not a bunch of these hobble along, many
failing. Why do not some of these bump into one another, merge membranes,
and combine into a single entity. Why don't some absorb an entire protein or
rna molecule that was floating around when some other replicator
disintegrated.

Imagine this happening over millions of years and you may end up with
organism similar in structure and composition, yet there was no single
ancestor.


There is no reason to assume a single progenitor,
unless one goes back to the big bang.

And that is the conclusion you draw based entirely
on your bushel basket full of false premises.

What false premise?


Why in the world do you come to that conclusion?

A least common ancestor is a least common ancestor,
even if that turns out to be just a first molecule
capable of self replication.

A single molecule may be able to replicate itself, but the idea that that
molecule can continually be modified and still self-replicate is contrary to
common sense (that is, a biochemist's common sense).


There is no _requirement_ that the LCA be a cellular
creature, but every reason to believe that such is
is true but only "in a sense".

That sense is the sense of "an LCA working as we
understand life to work today"; metabolisms, energy
sequestering, a somehow interpreted "blueprint"
mechanism[*] for building a child/sibling cell, etc.

You are assuming that the LCA had all this? So there were all kinds of
pre-LCA entities floating around that in every way but one was a cell. Then
voila, the mutation, and the complete cell came to be, and beat out all the
competitors. Or are you suggesting a sequence of common ancestors; the LCA
becomes varied, and one day one descendant becomes a prodigy and eliminates
all the others, and then of its descendants one comes up with cytochrome c
and good-bye to all its relatives, and of its descendants one brings the
citric acid cycle to completion, and so good-bye to all its relatives.
Considering the number of mechanisms within a single cell, this would happen
a few thousand? times.


That sense is also the "usual" sense, because we
want "inheritance of variation" to happen, and up
until the point that the genetic material is
encapsulated by cell walls and so protected from
immediate encroachment, mixing and merging of the
multivariant descendents of the first replicating
molecules which learned to be robust to variation
would presumably be constantly occurring.

Life still manages today to pass info across species lines.


FWIW

xanthian.

[*] The early blueprint might well be implicit,
though, rather than DNA-like, if each separate
component of the single cell were separately
self-replicating and shape-constrained to put the
replicated parts together inside correct cell wall
boundaries, or else self-assembling that way when
replicated in close proximity.



.

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