Evolution???

[Vocaloldfart]

It is estimated that the age of the earth is 4.54 billion years +/- 0.05 billion years.
First life began (scientific guesstimate) at 3.8 billion years ago. That is it took only 0.75 billion years for life to appear on the new world.
In universal terms that would be just an instant.
Let's speculate how life started.
We have an ocean called the primordial soup ( a sea of serendipitous synchronicity and coincidences) into which one day falls and asteroid bringing with it hydrocarbons.

One day a lightening bold this some of these hydrocarbons and a single cellular microbe is born.

Which dies .
For how long did this occur??

One smart microbe gets the idea that it wants to continue living.
Real smart, as it did not have a brain yet. So it goes on a trial and error trip and through countless generations realises that it needs a plan .
Co_incidentally atoms are grouped to make different structures. The primordial soup creates proteins These combine and create structures. Some of which make up DNA which is of 3 parts :--
1 A Five Carbon Ring
2. Nitrogenous Base
3. A Phosphate Group.
A very obliging primordial soup supplies this on demand in just the right combinations of atoms.
The first "Just in time" manufacturing logistic operation.

Great our microbe now has a plan. Poof it dies for countless more generations because it has the plan to make more microbes, but a plan is not a house built, so it dies.

So it gets the idea to make RNA which is both messenger/truck and workhorse..
OK now let's look at DNA and RNA

DNA is a double-stranded molecule, while RNA is a single-stranded molecule.
DNA is stable under alkaline conditions, while RNA is not stable.
DNA and RNA perform different functions.
DNA is responsible for storing and transferring genetic information, while RNA directly codes for amino acids and acts as a messenger between DNA and ribosomes to make proteins.
DNA and RNA base pairing is slightly different since DNA uses the bases adenine, thymine, cytosine, and guanine; RNA uses adenine, uracil, cytosine, and guanine. Uracil differs from thymine in that it lacks a methyl group on its ring. All supplied just in time and at the right place from the primordial soup.

OK now we have the microbe with not only the draft plans but also the builder to make the next microbe.. hang on Houston we have a problem!
We need a brain (nucleus)to coordinate and we need a factory to make the building materials.
Time passes and it is now done Hey I am alive.
I discovered a way to reproduce along the way without destroying myself. Mitosis. I am alive and now have my own inbuilt factory.

Was I the first microbe from which you evolved???

No because the plant DNA microbe produced the oxygen which I needed to breathe even in the water.
I need oxygen to make the building block proteins and sugars on which I feed called respiration.
Now all this is very interesting, but were it not for the original smart cookie  hydrocarbon  being hit with lightening and going through all  the above processes ,first to become a flora microbe, then there would not be the oxygen  for the fauna microbe to develop as we now know it.

Although their functions are the same, plant and animal DNA is not the same.
The main difference between plant and animal DNA is due to their base sequence arrangement.
Both plant and animal DNA molecules are formed from the same four nucleotides, but the only difference lies in the order of the base sequences. The sequence of the bases decides on the proteins to be synthesized.
The arrangement of the nucleotides will determine how the plant or animal will turn out to be and what traits it will possess.
Another differentiating point between plant and animal DNA is that plant DNA is slightly larger than animal DNA. Also, the isolation of plant DNA is more difficult than that of animal DNA.
Despite being so different from each other, both plant and animal DNA perform the same function, which is expression of hereditary characteristics and cellular development.

[billy rubin]

it is interesting to me that all things we call "living" use DNA to code some sort of genetic mechanism. RNA in some viruses.

a pretty fundamental single common ancestor is logically implied.

what things might be called "living" thst dont contain it?

is there a definition of life that isnt circular?

[Vocaloldfart]

it is interesting to me that all things we call "living" use DNA to code some sort of genetic mechanism. RNA in some viruses.

a pretty fundamental single common ancestor is logically implied.

what things might be called "living" thst dont contain it?

is there a definition of life that isnt circular?
 Some viruses do not have DNA but do use RNA.
The genetic coders were not a very imaginative lot.

My contention when I penned that discussion topic was the astronomically long impossible odds of all these ingredients and factors coming together in the right time and places to actually form life of any sort in the first place.

[billy rubin]

My contention when I penned that discussion topic was the astronomically long impossible odds of all these ingredients and factors coming together in the right time and places to actually form life of any sort in the first place.

each one of the little dots of light on this image is a galaxy containing billions of stars.

in a population of that size, rare events are statistically quite likely to be present, such as life.

in the event of that quite likely rare event, it is also likely that we would be having this conversation

so im not surprised that life exists, here and now, and that we are discussing it.

what other forms could it take, besides DNA? i am using a DNA molecule as the lowest possible form of something i would call living, courtesy of my favorite moron, richard dawkins.

[Recusant]

This is a game that I'm not qualified to play. Though I believe I have more scientific knowledge and understanding than the average citizen, that isn't saying much. Note that there is a sticky thread in the science board which has covered advances in scientific investigation of abiogenesis. 

At this point it is a game though, the Drake Equation and other stabs at informed speculation notwithstanding. Even fully qualified professionals who specialize in the field will freely admit that (underscored below).

The new equation breaks down the process of abiogenesis — the formation of life from nonliving components — into a series of simpler factors. Those factors incorporate the planet's conditions, the ingredients needed to form life and the likelihood of those ingredients getting into the right configuration for life to emerge. As with the Drake equation, each of the terms is straightforward to describe, but each hides additional complexity and room for new research.

The value P_a, which is the probability that life will assemble out of those particular building blocks over a given time, is murkier — and much more interesting. If the value of P_a is very low, it's extremely unlikely that life will form even when the ingredients are there — potentially explaining why humans haven't yet happened to create life in the lab, even if scientists have used the right ingredients, Scharf said. But a planet-wide "lab" would increase the odds that life-creating events will occur.

"We might have to wait 100 million years for it to fall into place just in a test tube," Scharf said. "Whereas on a planet scale, you've got a trillion test tubes — probably even more than that. It's conceivable that, using this equation, playing these games, is hinting at a possible explanation for why we haven't seen life miraculously appearing in our laboratories, that ... there's some subtle thing that has to happen that really doesn't happen often."

Since I have but a cursory understanding of some of the elements of the equation I'd only be stating an uninformed opinion regarding how "likely" it is for life to form in our universe, or on Earth. However, the image posted by billy rubin makes a powerful statement regarding an argument from assertions of statistical improbability.

Those arguments seem to be a way to buttress a notion that Earth is special, beyond simply being in the "goldilocks zone" and having a large moon. That's a path I discarded a long time ago.  Our universe self-evidently is one in which life can form. Beyond that we're still exploring and opinions abound.