the breadth of modern biology

[Kuznetzova]

I will start out immediately posing three ponderous questions:

1. Why do all organisms on earth all use DNA to encode their inherited traits? Why not PNA? Why not double-stranded RNA?
2. Why do all living organisms on earth regrow from 'scratch', from a fertilized egg?
3. Why does fungus go through the process of sexual reproduction?

Some elaboration.

1. Why do all organisms on earth all use DNA to encode their inherited traits? Why not PNA? Why not double-stranded RNA?

Biologists were recently forced (by common sense) to split single-celled organisms taxonomy into a third kingdom of life, dubbed Archaea. Those organisms cellular machinery was simply too alien to fit into "bacteria". Through some wild coincidence, even the Archaea encode their traits in DNA. They could easily be using a form of RNA, or Peptide Nucleic acid, (or something else), but no. Even they also use the familiar DNA molecule, just as in all other kingdoms of life. But why?

2. Why do all living organisms on earth regrow from 'scratch', from a fertilized egg?

We can imagine some long worm that lives in the oceans It grows very long, so long that it eventually splits into two worms, who then go about growing in their own lives. Or we could imagine some sort of tree that grows a sapling out of the side of its trunk, which after some time splits from the parent, falls to the ground, roots into the soil, and begins its own life growing towards adult-sized. Or perhaps large fungus that spreads over dozens of meters in topsoil, after which it splits in pieces that are the offspring of the parent fungus. Or any other interesting variation of budding or splitting by sea sponges or the like.

But this is not seen in any form of life anywhere. With zero exceptions, all life on earth re-starts the entire phenotypic development cycle from a single fertilized egg. Trees still fertilize flowers with pollen, fungus still uses spores, and fish and mammals still use the sperm combining with an egg. What is the reason for this?

3. Why does fungus go through the process of sexual reproduction?

Fungi are forms of life that are even simpler than plant life. There is a fungus whose entire genome can fit on the front of a t-shirt. They have no central nervous systems and they don't move around. There is no nest to protect, nor food to hunt, nor vulnerable offspring to raise. Despite all these facts, many species of fungi still reproduce sexually, particularly during the spore stage. What in the world is the use of that? Generally speaking, why is sexual reproduction seen in simple organisms when their lives have no conspicuous use for such a thing?


The three questions presented above only recently came under the purview of scientific inquiry. And by "recently", I mean since approximately the year 1950. Prior to that, science lacked both the data and the tools to even begin to approach any sort of rational answer to them. For the vast majority of human history, the official answer to all these questions like those above was simply "That's the way God wanted it" or "That's the way God intended it." At best, a wholly hypothetical, philosophical answer could be given.

__
Since 1950, an entire branch of science has been born and developed called Molecular Biochemistry. Students on campus might speak of it as "biochem". Biochem has since undergone a synthesis with the theory of evolution by natural selection. The results of this synthesis came to widespread public attention, via Richard Dawkins book, The Selfish Gene, published in 1976. Now that the theory of Natural Selection is reinforced by biochemistry and armed with genetics, the three questions above now can be (nearly) answered with a rational, scientific explanation. This is ironic, since only recently were they could only be grappled with by theologians.

The breadth of modern biology has expanded this far right inside of the lifetimes of my parents. As more synthesese take place in the future, biology will extend even further in its capacities to answer questions about life and its place in the universe. I an confident that some day, a grand synthesis of biology with the other sciences will allow us to answer questions about life in the universe, and even about its origins on earth, and elsewhere.

[jackles]

So dna adapts to the most convienient form to evolve a higher state of being.the dna its self being the most convenient carrier of imformation or meaning.seaking to establish the highest possible consciouse form for the given event enviroment.

[Kuznetzova]

Thanks for reading and taking time to reply.

[jackles]

From you photo you look like the tsarena of all the russias.i imagine you have that accent which goes well with scientific stuff.

[Kuznetzova]

It's not me, but I'll tell her you said that.

[Arising_uk]

Given your thoughts and opinions if you know that girl and she is under-age then you should stay well away from her.

[Kuznetzova]

Given your thoughts and opinions if you know that girl and she is under-age then you should stay well away from her.

non sequitur

[Arising_uk]

Oh I think it follows very well.

[Kuznetzova]