I ... favor ... "alien" colonization for the original ... organisms on this planet

Joe

I am also responding here by a blog post to your follow-up comment because it raised the issue of Panspermia. Again my words are in bold to distinguish them from yours. I am still working on part #2 of my response to your first comment.

Joe G said...

JG>You are on no schedule to respond to my rants. That you responded at all is good enough. Thank you.

If it was just a "rant" I would not have responded.

JG>Common ancestry- I have read most of what you posted in your essay. Obviously I missed (didn't read) some of your other work or I would have (and should have) realized you already discussed the "Essential genome of minmal bacterium". My apologies for that.

Thanks, but there was no need to apologise.

JG>My point is what can be modified in a population of "bone-less" inverts that would give rise to "boned" vertebrates?

Bone is a soft tissue that hardens, being derived from mesoderm tissue. After all, boneless (e.g. human) vertebrate embryo becomes a boned vertebrate adult. There is also an intermediate between bone and boneless, namely cartilage, not to mention the calcium exoskeleton secreted by molluscs and indeed the calcium endoskeleton in echinoderms (starfish).

JG>The only answer I ever get is "DNA!", which I say is a bogus "answer".

It is not only "DNA" but new specialised bone-forming cells including osteocytes.

JG>But hey I am the lunatic who favors "alien" colonization for the original populations of organisms on this planet. And even though that just "pushes things back" I say that science has to go with what we have and keep searching for more. IOW solve OUR reality then figure out the next step.

As your critics say, it just "pushes things back". The same problems of life originating and developing (including boneless becoming bone) had to be solved somewhere.

A major problem with interstellar panspermia (apart from cosmic radiation which would sterilise any life enroute to Earth across interstellar distances) is the time frame. The Universe is ~14 billion years old and life on Earth began ~4 bya. That was when the Universe was ~10 billion years old and a very different place. The volume of space was much smaller (since volume increases by the cube of distance) and radiation much greater because radiation falls off with the square of distance. So the combined effect of both was that radiation was very much greater. For life to arise somewhere else, develop, then cross interstellar space and arrive here, means it had to originate well before ~4 bya (say ~5 bya) when the Universe was an even more hostile place.

There is also the `needle in a haystack problem' that one of my (atheist) biology lecturers pointed out. The Earth from the perspective of another interstellar exoplanet is an invisible point (even with a telescope). Unless one is arguing for Directed Panspermia (in which case one has to factor in the extra time frame for intelligent technological beings to arise- on Earth it took ~4 billion years), it is effectively impossible for a bacterium to be wafted undirected by its star's solar wind (which raises another problem in that our star's (the Sun) solar wind would blow it away from our Solar System), and find Earth (and then survive the entry on an Earth that was undergoing the Late Heavy Bombardment ~3.9 bya with lethal UV rays on its surface since there was no ozone layer).

I have added the above (in a clearer 6-point format) to my "Problems of Evolution" book outline, PE 7.6.4. "Problems of origin of life locations ... Panspermia".

JG>Off topic:

But here is a serious question- DNA replication and transcription-

It's not "off topic".

JG>When the DNA is "unzipped" an existing "stock-pile" of nucleotides is used to make the necessary copy (either of the entire sequence or the "gene").
>
>Where does that "stock-pile" come from? I can't find it in any biology literature.

The "stockpile" is comprised of "deoxynucleoside triphosphates" "(dATP, dTTP, dGTP, and dCTP)" which are in the cell nucleus' cytoplasm and are added by DNA polymerase (an RNA/protein molecular machine) according to Watson-Crick complementary base-pairing rules, to a single strand of DNA (exposed by DNA polymerase):

"When the semiconservative model of DNA replication was first proposed in the early 1950s, biologists thought that DNA replication was so complex it could be carried out only by intact cells. A few years later, however, Arthur Kornberg found that an enzyme he had isolated from bacterial cells could copy DNA molecules in a test tube. This enzyme, which he named DNA polymerase, required that a small amount of DNA be initially present to act as a template. In the presence of such a template, DNA polymerase catalyzes the elongation of DNA chains using as substrates the triphosphate deoxynucleoside derivatives of the four bases found in DNA (dATP, dTTP, dGTP, and dCTP). As each of these substrates is incorporated into a newly forming DNA chain, its two terminal phosphate groups are released. Since deoxynucleoside triphosphates are high-energy compounds whose free energy of hydrolysis is comparable to that of ATP, the energy released as these phosphate bonds are broken drives what would otherwise be a thermodynamically unfavorable polymerization reaction. In the DNA polymerase reaction, incoming nucleotides are covalently bonded to the 3' hydroxyl end of the growing DNA chain. Each successive nucleotide is linked to the growing chain by a phosphoester bond between the phosphate group on its 5' carbon and the hydroxyl group on the 3' carbon of the nucleotide added in the previous step .... In other words, chain elongation occurs at the 3' end of a DNA strand and the strand is therefore said to grow in the 5' -> 3' direction." (Becker W.M., Kleinsmith L.J. & Hardin J., "The World of the Cell," [1986], Benjamin/Cummings: San Francisco CA, Fourth edition, 2000, p.540)

By the way, DNA polymerase seems to be yet another rotary molecular machine!

I assume the deoxynucleoside triphosphates in turn are formed by other cellular machinery from the nucleotide bases and phosphates in food. Although photosynthetic bacteria (cyanobacteria again) and plants don't ingest food with A,T,G & C in them (they make their food from the carbon and oxygen in the air and water, and take in soluble phosphorous in water) so maybe animals synthesise the deoxynucleoside triphosphate DNA precursors (dATP, dTTP, dGTP, and dCTP) from scratch? The four DNA nucleotide bases, Adenosine (A), Thymine (T), Guanine (G) and Cytosine (C) are comprised only of N, H and O molecules.

It was, by the way, "biologists' investigation of DNA" which was specifically cited by fomer leading atheist Antony Flew (author of a book "Darwinian Evolution"), as among "the almost unbelievable complexity of the arrangements which are needed to produce (life)" that convinced him "intelligence must have been involved":

"A British philosophy professor who has been a leading champion of atheism for more than a half-century has changed his mind. He now believes in God -- more or less -- based on scientific evidence, and says so on a video released Thursday. At age 81, after decades of insisting belief is a mistake, Antony Flew has concluded that some sort of intelligence or first cause must have created the universe. A super-intelligence is the only good explanation for the origin of life and the complexity of nature, Flew said in a telephone interview from England. Over the years, Flew proclaimed the lack of evidence for God while teaching at Oxford, Aberdeen, Keele, and Reading universities in Britain, in visits to numerous U.S. and Canadian campuses and in books, articles, lectures and debates. There was no one moment of change but a gradual conclusion over recent months for Flew, a spry man who still does not believe in an afterlife. Yet biologists' investigation of DNA "has shown, by the almost unbelievable complexity of the arrangements which are needed to produce (life), that intelligence must have been involved," Flew says in the new video, "Has Science Discovered God?" … The first hint of Flew's turn was a letter to the August-September issue of Britain's Philosophy Now magazine. "It has become inordinately difficult even to begin to think about constructing a naturalistic theory of the evolution of that first reproducing organism," he wrote. … Flew told The Associated Press his current ideas have some similarity with American "intelligent design" theorists, who see evidence for a guiding force in the construction of the universe." (Ostling R.N.,"One of the world's leading atheists now believes in God, more or less,"San Francisco Chronicle/Associated Press, December 9, 2004. My emphasis).

Stephen E. Jones, BSc (Biol).
"Problems of Evolution"