reply to post by Zenithar
I assure you I am not making the mistake, if you had read through my previous answers and thread you would no that i am neither a creationist nor do i
confuse evolution with abiogenisis,
I didn't mean to imply that at all, I was pointing out that the first bit of the video was aimed at those people, that is why I directed you to the
interesting part.
I am talking about the first oganissm THAT HAD these systems, not where or when they originated, we know that at some point, single celeld organisms
would replicate many millinos of time, im simply saying that if dna repair was not there, there dead,
But you are wrong. If DNA repair is not there, then the population may be unstable but individuals still exist and live out whatever life they live
out, but when they reproduce, the offspring
may be radically different from parents, and there
may be a huge mortality rate. This is not
a difficult concept to understand, millions of human sperm are produced to fertilize one egg, the high mortality rate for sperm is not only not a
problem, it allows for the vast majority of uncorrected replication errors to be 'filtered' out (defective sperm are usually slow swimmers). The FACT,
not belief, FACT, that life survived this problem is self authenticating proof.
and if it is there, and the enzyme topoisimerase is not at the same time, its dead,.. so surely its a belif system to think these components were
present at this right time!
You have to understand that only DNA damaged individuals are at risk. If there are millions of individuals in the population, high mortality rates can
be absorbed with little or no impact on the population as a whole. DNA errors don't strike every individual, it is only when the populations get quite
small that an unrepaired fatal DNA mutation would cause problems.
now i think its you making assumptions " inevitable in the environment as it existed at the time the first life 'started'. now this is a crazy
statement, firstly that whol enviroment is hypothetical,
I clearly stated that this is one of many possible models. The described 'hypothetical' environment is not really very hypothetical, it is based on
solid evidence, but it is true that it is not certain. As the disclaimer I quoted states, we'll never know exactly how life started, but we will know
many ways it could have started. If we identify all (an impossible absolute, of course) possible pre-existing situations and show how life would have
started in each, then we may not know for certain which one was operative, but we certainly know that it could have started in some way.
and second, it is not inevitable at all,
In the environment described the chemistry and the physics would make the processes described inevitable. It is simple, well understood, organic
chemistry and physics. Even though the exact conditions of that environment is uncertain, the physics and organic chemistry would work in a wide range
of possible pre-biotic environments. Some of those environments exist even today; although life has radically changed the chemical composition of the
oceans, the environment near sea vents are quite similar to what could have been expected in the pre-biotic ocean.
how would those without clotting survive so many generations of "waitign for blood clotting to arive"
By not getting damaged at least until they had reproduced? Or by not having a circulatory system that suffers a fatal leak when damaged? Does a
'ciculatory system' necessarily imply a 'modern' tube system driven by a pump?
Or maybe the clotting capability did come first and made it possible for tubes and pumps to evolve later.
and what about when they multiplied, without topoisimerase present, supercoiing prevents the informatino bieng
read,
Only if the strands are long enough to coil. And only if they are 'modern' DNA nucleotides.
You seem to have a blockage that two dependent processes could only have been evolved in parallel. Today an automobile could not exist without a
steering wheel, but the first cars didn't use a steering wheel. And the wheel was invented millenia before the automobile. Things don't necessarily
happen in lock step in evolution either.
you say... At some point down the track a random mutation threw up the DNA repair mechanism
this is wherer the faith comes in for me, i mean, most of what you described above is obvious, its simply what would happen IF those proposed
circumstances actually happend, we cannot simply accept it did.
We must accept the fact of existence, there is no faith involved in existence, it either is or it isn't. Since it is, then there are few
possibilities: supernatural creation of full blown complicated DNA with error correction enzymes in place, evolution of DNA without error correction
enzymes present, synthesis of error correction enzymes separate from and prior to DNA serendipitously in place for when DNA happens along. The first
is faith based on the existence of a supernatural force, the other two can (in theory) be demonstrated with out reliance on faith.
i am a searcher of knowledge and never take this kind of thing on authority but dig in and form my own opinion,
An honorable ambition. Be careful not to fall into the trap of thinking that one person in one lifetime can reproduce the entire knowledgebase of the
human race. Also remember that scientists don't form opinions on this stuff, they observe and experiment and extrapolate and argue and disagree and
synthesize theories from hypotheses.
When an hypothesis has been demonstrated to successfully describe a phenomena and make successful predictions it becomes recognized as a theory. When
that happens, scientists can accept it as a building block for further work, and not have to return to first principles for everything that is already
well understood. Yes new findings sometimes identify holes in existing theory and corrections are required, but when the correction is being
formulated, the work that went into the original theory does not have to be revisited, only that part that is affected by the new data. Einstein
didn't overthrow Newton. Pool tables and inclined planes still work the same way they always did. Einstein just solved more problems than Newton could
and showed where Newton's limits lay.
you say "Lack of these features do not automatically make an organism unviable"
can you demonstrate this to me? i mean , it dosent matter that much in terms of my argument but id be very interested to see a currently living
organism of this type.
Well, I am not personally familiar with any specific examples of species existing today with a circulation system and without a blood clotting
mechanism if that is what you want. However I can point you to human hemophiliacs that survive quite well as long as they don't get damaged. This is
not a satisfactory answer to your question, but it does make a point. The important thing in evolution is the population, not the individual. You have
to get beyond the individual to the population. If there are millions of individuals in a generation, a high mortality rate is easily absorbed.
Turtles lay hundreds of eggs in a generation, but only a few individuals survive. It is the population that counts, not the individual.
Furthermore, I can point out that even with DNA repair mechanisms in modern cells, not every DNA error is corrected, thus evolution continues. Some of
these errors produce drastic birth defects. Not all birth defects are fatal at birth and individuals live for many years, even normal lifespans, and
even reproduce. DNA damage to an individual is clearly not necessarily fatal to the individual, and obviously not to the population as a whole.
I can refer you to
CB 200.2: Blood Clotting and Irriducible Complexity for a critique of
the notion that circulation and clotting are 'designed'.
Several references are provided at that page thay may be helpful to you in your knowledge search. It appears that Dolphins and Pufferfish survive
quite well without all the recognizable components of blood clotting mechanism.
How about plants? Plants have a circulation system and not all of them 'clot' and humans take advantage of that fact to gather the sap of the rubber
tree and the maple tree.
those cells that did not have blood clotting in the early earth, how would they survive all those replications without dna repair?
What does blood clotting have to do with DNA repair? I'm not sure which question you want answered.
Organisms with a circulation system but without a clotting mechanism would only be in trouble when they were damaged. Not every individual gets cut
and bleeds to death, and remember, the individual only has to survive to reproduce anyway. It is the population that has to survive, not the
individual.
DNA errors in an individual does not affect the entire population, only the individual. Not every reproduction results in 'errors' in DNA, not every
DNA 'error' is fatal, some DNA 'errors' are beneficial. If a DNA 'error' is beneficial to the individual's reproduction capability, that individual
will pass it into the population via its descendants so that the population as a whole will gain the benefit. If a DNA 'error' is detrimental to an
individual's reproduction capability, it won't pass into the population because there will be fewer or no descendants to carry it.
wouldnt it be a lot more likey that they would all die,
No, it would be extremely unlikely that they would all die. Only individuals that got cut somehow would die. As long as enough individuals survived to
reproduce, the population would continue. They are in the ocean, what is going to cut them? Is the entire population going to bounce off rocks?
infact the supposed atmosphere of that tiem would ravage anything not adapted,
Since this was going on in the ocean, the atmosphere wouldn't make any difference to this problem. By the way, the atmosphere is as we know it today
because life has made it that way; life didn't adapt to the atmosphere, life adapted the atmosphere to life!
dna repair was surely teh least of a small cells worries!
DNA repair would have been detrimental to early life, by my way of thinking. Even though the mortality rate may have been higher for individuals, a
high mutation rate would increase the gene pool quickly. Stabilizing DNA acts to slow down the mutation rate.
edit on 30/10/2010 by rnaa because: missed an end quote
