Origin of life

**sigurdV** · 06-11-12, 05:47 PM

Take a look at wikipedia:http://en.wikipedia.org/wiki/Origin_of_life
Do you find any proof, in there, that life originated somewhere on Earth?
Here is the earliest dissident:http://en.wikipedia.org/wiki/Svante_Arrhenius
What do YOU think?

**Buddha12** · 06-11-12, 07:29 PM

Do you find any proof, in there, that life originated somewhere on Earth?

The first living things on Earth are thought to have been single-cell prokaryotes (which lack a cell nucleus), perhaps evolved from protobionts (organic molecules surrounded by a membrane-like structure).[1] The oldest ancient fossil microbe-like objects are dated to be 3.5 Ga (billion years old), approximately one billion years after the formation of the Earth itself,[2][3] with reliable fossil evidence of the first life found in rocks 3.4 Gyr old.[4] By 2.4 Ga, the ratio of stable isotopes of carbon, iron and sulfur shows the action of living things on inorganic minerals and sediments[5][6] and molecular biomarkers indicate photosynthesis, demonstrating that life on Earth was widespread by this time.

From your link.

I think that says that life started back then.

**Epictetus** · 06-11-12, 10:33 PM

I've said it in other threads, and so have others: Why is it so unacceptable that life began on Earth? Why does it have to be an asteroid, or 'seeding' aliens? I would think Earth is a wonderfully well suited cradle for protein molecules and the origin of life. There is no harm in speculating that life originated off world and was brought here, but what about Occam's razor? The simplest answer is often correct.

**sigurdV** · 06-12-12, 06:08 AM

Originally Posted by Buddha12

The first living things on Earth are thought to have been single-cell prokaryotes (which lack a cell nucleus), perhaps evolved from protobionts (organic molecules surrounded by a membrane-like structure).[1] The oldest ancient fossil microbe-like objects are dated to be 3.5 Ga (billion years old), approximately one billion years after the formation of the Earth itself,[2][3] with reliable fossil evidence of the first life found in rocks 3.4 Gyr old.[4] By 2.4 Ga, the ratio of stable isotopes of carbon, iron and sulfur shows the action of living things on inorganic minerals and sediments[5][6] and molecular biomarkers indicate photosynthesis, demonstrating that life on Earth was widespread by this time.

From your link.

I think that says that life started back then.

How do you get from "Life on Earth was widespread by this time." to the conclusion that life originated on earth?

**sigurdV** · 06-12-12, 06:17 AM

Originally Posted by Epictetus

I've said it in other threads, and so have others: Why is it so unacceptable that life began on Earth? Why does it have to be an asteroid, or 'seeding' aliens? I would think Earth is a wonderfully well suited cradle for protein molecules and the origin of life. There is no harm in speculating that life originated off world and was brought here, but what about Occam's razor? The simplest answer is often correct.

Why do you claim that the simplest answer is that lifes origin is on Earth?

Is it because it is simplest to conform to general opinion?

Or can you back up your claim scientifically?

**sigurdV** · 06-12-12, 06:28 AM

Hi all participators!

The thesis I defend is:There is no proof that Earthly life originated on Earth.

And I will defend the prediction: There will be no such proof!

**DaveC426913** · 06-12-12, 08:33 AM

As with the last one, discussions of the unearthly origin of life are not appropriate for the Bio & Gen Forum. Thread has been reported, to be moving to a more apporpraite forum, or, even better closed as a duplicate of this thread: http://www.sciforums.com/showthread.php?t=114053&page=2

**RoccoR** · 06-12-12, 09:24 AM

Epictetus, et al,

No one knows hw life (on Earth) started.

Originally Posted by Epictetus

I've said it in other threads, and so have others: Why is it so unacceptable that life began on Earth? Why does it have to be an asteroid, or 'seeding' aliens? I would think Earth is a wonderfully well suited cradle for protein molecules and the origin of life. There is no harm in speculating that life originated off world and was brought here, but what about Occam's razor? The simplest answer is often correct.

(COMMENT)

Life, as we define it, has an unknown origin. We understand that at a certain point, simple forms of life emerged. But no one knows if humanity traces back its origins to those few simple life forms, or if something else, off-world, was a trigger for the strand called humanity.

There are several theories. Some with evidence, and some with out. But the "idea" that the trigger came from off-world is neither more likely or less likely. Remember, everything on the planet is made of star dust. All the atom in our bodies came from the stars. So, whether it is home made soup (of life), or delivery, it all started out the exact same. There is simply insufficient evidence on either side, supporting any theory, to argue one way or the other with any confidence. It could even be the case that life on the planet is a composite of both types.

Most Respectfully,
R

**sigurdV** · 06-12-12, 10:25 AM

My thesis is: There is no evidence that the origin of Earthly life was on Earth.

Produce evidence against my thesis and I will examine:
If I find the evidence convincing I will consider my thesis disproven.
And I will tell everybody so.

Isnt that what science is about?

**sigurdV** · 06-12-12, 10:41 AM

Originally Posted by RoccoR

Epictetus, et al,

No one knows hw life (on Earth) started.

(COMMENT)

Life, as we define it, has an unknown origin. We understand that at a certain point, simple forms of life emerged. But no one knows if humanity traces back its origins to those few simple life forms, or if something else, off-world, was a trigger for the strand called humanity.

There are several theories. Some with evidence, and some with out. But the "idea" that the trigger came from off-world is neither more likely or less likely. Remember, everything on the planet is made of star dust. All the atom in our bodies came from the stars. So, whether it is home made soup (of life), or delivery, it all started out the exact same. There is simply insufficient evidence on either side, supporting any theory, to argue one way or the other with any confidence. It could even be the case that life on the planet is a composite of both types.

Most Respectfully,
R

Hi! And thanks for your "balanced view"!
I spot nothing wrong in your post, but perhaps I will later,when my opponents have stopped trying to silence me,
and if my thesis is not disproven, discuss the alternatives to the unfounded belief that lifes beginning was on Earth.

**spidergoat** · 06-12-12, 11:43 AM

There is no evidence that it didn't originate on Earth. Given the distance between any suitable place for life to evolve (hasn't been found yet) and Earth, it's still more likely that life started on Earth, but perhaps with some help from organic molecules from space. Proof is a problematic concept in this field.

**origin** · 06-12-12, 11:51 AM

Originally Posted by sigurdV

My thesis is: There is no evidence that the origin of Earthly life was on Earth.

Produce evidence against my thesis and I will examine:
If I find the evidence convincing I will consider my thesis disproven.
And I will tell everybody so.

My thesis is that an alien named Bob from the planet armadillo traveled here and used earth for a potty break seeding the earth with the first life.

Produce evidence against my thesis and I will examine:
If I find the evidence convincing I will consider my thesis disproven.

**Tero** · 06-12-12, 12:31 PM

Ok, life originated on earth or somewhere else in the universe. It was the same process, nevertheless. What's the problem?

**Billy T** · 06-12-12, 04:28 PM

As life probably originated on a planet orbiting a star with Earth like conditions (perhaps several times independently on different planets in our galaxy) it seems more likely that Earth´s life originated on Earth as to have come from some other planet, it would have been subjected to very harsh UV for a few thousand years as the radiation pressure from the star of origin pushed it slowly away into space - I.e. I suspect that "space traveling" life would be killed by the harsh UV and reduced to at most some organic molecules.

Conversely, I can believe some of Earth´s most primitive "living" molecules do leave the Earth but expect that before radiation pressure drives them as far away as Pluto, they are all reduced by Solar UV to simple molecules.

**sigurdV** · 06-13-12, 02:53 PM

Originally Posted by Epictetus

I've said it in other threads, and so have others: Why is it so unacceptable that life began on Earth? Why does it have to be an asteroid, or 'seeding' aliens? I would think Earth is a wonderfully well suited cradle for protein molecules and the origin of life. There is no harm in speculating that life originated off world and was brought here, but what about Occam's razor? The simplest answer is often correct.

Its not unacceptable at all, but why do you think its the simplest answer?

What is there to compare? Is there another serious answer?

How about Space? Either lifes origin was on a planet or in space

Is it possible for life to have its origin in space? What say you?

**sigurdV** · 06-13-12, 03:18 PM

Originally Posted by origin

My thesis is that an alien named Bob from the planet armadillo traveled here and used earth for a potty break seeding the earth with the first life.

Produce evidence against my thesis and I will examine:
If I find the evidence convincing I will consider my thesis disproven.

Parts of your thesis are silly:
No alien is named Bob
No planet is called Armadillo
But its consceivable that life didnt originate on earth.

Your theory obviously attempts to be an argument for the thesis that life has earth as its origin.
Its a bad ,dishonest,disingenious and not amusing argument, If you cant do better I suggest you go elsewhere.

**sigurdV** · 06-13-12, 03:29 PM

Originally Posted by Buddha12

The first living things on Earth are thought to have been single-cell prokaryotes (which lack a cell nucleus), perhaps evolved from protobionts (organic molecules surrounded by a membrane-like structure).[1] The oldest ancient fossil microbe-like objects are dated to be 3.5 Ga (billion years old), approximately one billion years after the formation of the Earth itself,[2][3] with reliable fossil evidence of the first life found in rocks 3.4 Gyr old.[4] By 2.4 Ga, the ratio of stable isotopes of carbon, iron and sulfur shows the action of living things on inorganic minerals and sediments[5][6] and molecular biomarkers indicate photosynthesis, demonstrating that life on Earth was widespread by this time.

From your link.

I think that says that life started back then.

No: What it says is that life was widespread back then.

**sigurdV** · 06-13-12, 03:55 PM

Originally Posted by Billy T

As life probably originated on a planet orbiting a star with Earth like conditions (perhaps several times independently on different planets in our galaxy) it seems more likely that Earth´s life originated on Earth as to have come from some other planet, it would have been subjected to very harsh UV for a few thousand years as the radiation pressure from the star of origin pushed it slowly away into space - I.e. I suspect that "space traveling" life would be killed by the harsh UV and reduced to at most some organic molecules.

Conversely, I can believe some of Earth´s most primitive "living" molecules do leave the Earth but expect that before radiation pressure drives them as far away as Pluto, they are all reduced by Solar UV to simple molecules.

This post describes problems life has to face to survive in space as we consceive it today.
But space today is very different from the solar system as it was in the beginning.
There was less radiation and matter had not yet condensed into sun and planets...
Your argument seems limited to modern space...
not intended to cover all the changes the stellar system goes through from beginning to end.

**sigurdV** · 06-13-12, 04:07 PM

Originally Posted by Tero

Ok, life originated on earth or somewhere else in the universe. It was the same process, nevertheless. What's the problem?

It aint necessarily so!
Suppose weightlessness is a necessary condition, would then lifes origin be planetary?
Or conversely: if high gravity is a necessary condition.would then lifes origin be in orbit?
Are the necessary and sufficient conditions for the origin of life not of scientific interest?

**sigurdV** · 06-13-12, 04:13 PM

Originally Posted by spidergoat

There is no evidence that it didn't originate on Earth. Given the distance between any suitable place for life to evolve (hasn't been found yet) and Earth, it's still more likely that life started on Earth, but perhaps with some help from organic molecules from space. Proof is a problematic concept in this field.

Can you suggest what prevented the organic molecules from space to be scattered in the waters on Earth.