Life came from space

[MAraujo]

Even Shakespeare babbled around when he was a child.

Yes, your reasoning is totally logical, the problem is that we just don't see that "babbling" in the rock record. It appears that as soon as the earth was cool enough for water (about 4.2 billion years ago) BAM!!! life shows up in near full complexity. Today's most complex DNA is like 20 full volume sets of Encyclopedia Britannica word for word. Just 4.2 b.y.ago it was 14 full volume sets. The unbelievable uniqueness and complexity suggests that life grew from a very small extraterrestrial sample.

 

[NukeET]

The unbelievable uniqueness and complexity suggests that life grew from a very small extraterrestrial sample.

I don't quite follow your logic on this...

 

[Urwumpe]

Yes, your reasoning is totally logical, the problem is that we just don't see that "babbling" in the rock record. It appears that as soon as the earth was cool enough for water (about 4.2 billion years ago) BAM!!! life shows up in near full complexity. Today's most complex DNA is like 20 full volume sets of Encyclopedia Britannica word for word. Just 4.2 b.y.ago it was 14 full volume sets. The unbelievable uniqueness and complexity suggests that life grew from a very small extraterrestrial sample.

That is wrong and stupid. First of all, you can't measure the complexity of life by the length of the DNA. Many bacteria have far longer strings of DNA inside them than you have, despite being pretty simple lifeforms. They just have a huge amount of unused or specialist DNA.

Next, you are wrong on BAM! The geologic records are not suddenly full of complex life, because complex life suddenly appeared, but because less complex lifeforms did not end as fossils. You are right at this point about a minimum complexity, but this is rather the minimum complexity to become identifiable as life form.

The oldest fossil found is a microbe-like object and 3.5 billion years old. Now, this does not help you much about the complexity of life in the beginning. It is just a impression of a single cell. This was not right after the oceans appeared, but right at the same time, as the collisions of Earth with other proto-planets in the solar system happened less often, which sure erased more life from Earth, as it could have brought.

Also, if you look at complexity: It still took these primitive cells until 1.2 billion years ago, before they even developed sexual reproduction. Not that nothing happened in the 2.3 billion years before. Photosynthesis appeared already 3 billion years ago. But life evolved at a much slower pace until 1.2 billion years ago - most of the history of Earth was pretty much without the classic process of evolution.

Also, at the same time of sexual reproduction, multicellular life appeared - with or without sexual reproduction, is not known for sure. But we know the outcome: At one point multicellular life had also sexual reproduction as survival strategy.

 

[MAraujo]

I don't quite follow your logic on this...

Sorry, it is a bit of a logical leap. Life continually copies itself. If you start out with a variety of things with varied complexity you would expect a large number of possible combinations. I.e. My orbiter path folder is very different from yours or anyone else's. That is because there is a large variety of sources for addons. If you looked at every orbiter player's folder you would find that all of the folders have a basic set complex information in common (Martin's original base package). The commonality points to a single source. If all of our folders were close to or exactly the same it would be stronger evidence for a single source.

If orbiter was constructed completely out independent addons you would find very few commonalities between users. Statistically, there would be a chance that two people installed exactly the same addons in the same order but it would be rare indeed. It would be common to find small things in common with other users, but not 70% in common.

I hope that helps it might be a terrible metaphor, but ask yourself the question: If the entire population of say Brazil descended from a group of ten people and no outsiders ever showed up, what would that population look like after 4 generations? 10 generations? 100 million generations?

 

[Linguofreak]

Wow. 9 posts on the first day this thread was posted. 2 posts over a month later. Then it gets necromanced 8 months after that and generates 13 more...

 

[Hielor]

First off, nice thread necro. Nearly 9 months. Good job.

2. Life is left handed.
In nature, any 3d chemical compound (exept a perfectly symmetrical one) comes in two varietes: left and right, just like your hands, the same but opposite. All organic compounds produced by life are left handed. There's no reason why life couldnt equally be right handed but we just don't see that here. If life started here (all things being equal) it would have a high probability of forming both left and right varieties with no special preference.

{{Citation Needed}}. Also, maybe the left-handed ones worked and the right-handed ones didn't, for whatever reason.

3. Not enough time for evolution.
The most primitive life from 4 billion years ago has DNA that is only 70% of the complexity of the most complex life today. Evolutionary biologists today are confiedent that over geologic time DNA mutation rates are relatively constant.
To put it visually:

|--------------------| The complexity of life today
|--------------| The complexity of life 4 billion years ago
|---------| The complexity of life sometime before the Solar System

If you work out the rates it looks like you'd have to go back about 12 billion years, to see DNA as a relatively simple compound. This is almost reasonable in the scheme of the history of the universe.

{{Citation Needed}}. As Urwumpe points out, "complexity" of a DNA strand is not necessarily equivalent to how complex the organism is. In fact, given random combinations, one would expect there to be a whole lot more than necessary (Several thousand items combine to form a life form, but only ten of them are actually needed, it's just that with several thousand the ten that were needed were a lot more likely.

Religious discussions like this have no place in science.

 

[MAraujo]

First of all...

That is wrong and stupid.

How old are we? that is unnecessary.

Second of all, direct fossils are not the earliest positive evidence of life.

Thirdly, when I speak of complexity Im not talking about the length of DNA or the complexity of an organisms morphology. Im talking about bits of information in on the DNA. The most basic life needs a lot of instructions to do the most basic metabolic functions. Some adaptation that seems complex may not require much new information on DNA, and some adaptations that are relatively basic need phenominal amouts of information.

 

[Urwumpe]

How old are we? that is unnecessary.

No, it is something which can't be said often enough when people use inaccurate comparisons.

Second of all, direct fossils are on the earliest positive evidence of life.

Yes, but they are not the whole truth. Fossils show only a limited snapshot of the life at an era. You can tell, that at least one exemplar was around.

Thirdly, when I speak of complexity Im not talking about the length of DNA or the complexity of an organisms morphology. Im talking about bits of information in on the DNA. The most basic life needs a lot of instructions to do the most basic metabolic functions. Some adaptation that seems complex may not require much new information on DNA, and some adaptations that are relatively basic need phenominal amouts of information.

Actually not. You recite the "minimum complexity" argument of creationists, but these people argue by ignorance, and I don't recommend you to adopt such an argumentation style.

First of all, we don't know a bit about the DNA or RNA at the time. or about the proteins inside these cells. We have theories how it could be, but we can't find primordial DNA/RNA.

Second: There are many known ways to clone a strand of DNA or RNA without polymerase. It is not always a controlled reproduction, but you can do it. The polymerase, which better creationist arguments cite, is pretty much the Porsche among the DNA copy machines. That it exists, does not say, that life was impossible without out. It just says, that life was possibly not as effective then, as it was today. Which is sure no surprise.

You could for example have specialist proteins, for the many tasks, polymerase combines - creating a copy of a DNA strand would then take much longer than today, but it would work in a controlled way.

The important aspect is: A minimum complexity is a negative argumentation. You say that something is impossible (to find something less complex and still be life). But that argument always fails when something less complex as the status quo of the minimum complexity argument is found.

It is the same with computer algorithms. History is full of examples, where somebody declared that there is no solution for a problem in polynomial time, until somebody else found such a solution. It happened so often, that computer scientists are still not sure, if there is not always a solution in polynomial time for a problem which could be solved in non-polynomial time (P=NP problem).

 

[DarkWanderer]

Three facts about life that make it seem very likely that the Earth was seeded:

1. Life is unique.
That is to say that all life on earth is the same. It might not seem like this is the case when you look around your backyard, but there is nothing alive on earth that is not some form of bacteria. Even the cells in your body are nothing more than communities of bacteria. If there was a time when the earth was volitile and reactive you'd expect to see some variety of life.

2. Life is left handed.
In nature, any 3d chemical compound (exept a perfectly symmetrical one) comes in two varietes: left and right, just like your hands, the same but opposite. All organic compounds produced by life are left handed. There's no reason why life couldnt equally be right handed but we just don't see that here. If life started here (all things being equal) it would have a high probability of forming both left and right varieties with no special preference.

3. Not enough time for evolution.
The most primitive life from 4 billion years ago has DNA that is only 70% of the complexity of the most complex life today. Evolutionary biologists today are confiedent that over geologic time DNA mutation rates are relatively constant.
To put it visually:

Are you qualified enough to state that?..

just using chemicals that came from space.

And even more - the discovery states just that simple amines are created simplier, than it was thought. This actually counters the seeder's theory, not proofs. All we've got is just another I-wanna-believe journalist...

There's no worse thing than a combination of militancy and ignorancy.

 

[MAraujo]

I don't know how a geologist specializing in planetary climate science such as myself got labeled as a creationist, it couldn't be further from the truth.

I never said it was impossible to derive life on a planet like earth, a flip side to anyone of my arguments can be easily illustrated. I merely pointed to three facts about life that compel me to believe that life did not originate here. Probability allows for any possible number of permutations of compounds including DNA, sure. But we don't find what we would expect to find if life started here. What we do find fits very nicely with a cosmic seeding theory. I doesn't mean those assumptions will not be found to be wrong at sometime in the future.

 

[synonys]

someone has internalized the ignorant ID'ist arguments...

Phase 1: Life is too 'complex'
Phase 2: ?
Phase 3: Profit!

 

[RisingFury]

Whoa whoa whoa... let's not jump to conclusions here. The article says nothing about life coming from space, other then speculation and guesswork. If indeed the molecules came from space and did not contaminate the rock once it landed on Earth that doesn't mean they formed or helped form life on Earth. We see complex organics in quite a few places, even comets... there's organic chemistry going on on Titan.

This doesn't prove anything.

 

[MAraujo]

Life is too complex? too complex for what, too complex to form on earth at the currently observed rate of mutation? very possibly. Life certainly formed somewhere though and it likely did so in a primordial soup of organic compounds. But unless you provide some type of statistical "magic" to make incredible complexity very quickly(which I am not ruling out) it probably did so somewhere else. Improbable events happen all the time, but thats not a good reason to go to a casino and expect to walk away rich. I was using an empirical line of thinking for no other reason to engage in interesting conversation. I guess this is just the wrong crowd.

 

[Urwumpe]

Don't argue by authority here. We put authorities into the shredder and cut them into fine stripes. If you have no ways to argue in a rational way with people, log off and get a cool beer.

I merely pointed to three facts about life that compel me to believe that life did not originate here.

Yes, which does not keep us from showing you arguments, which are not countering your three trivialities, but instead show that life from space is not the simplest explanation.

Your three facts, as you call it, BTW, are one irrelevant fact and two unfounded assumptions - if you would be a real scientist, your academic conscience should be crying in pain.

1. Assumption, that there are not more ways tested in primordial history, which just did not survive until today.Also, the three basic families of life, we have today, are just general classifications with a broad range. No fact and no argument for life from space - but rather a challenge for geologists to find evidence for life which does not fit into the three main groups today.

2. Useless fact and logically build on sand. DNA and RNA are not simple symmetric, but complex molecules, which have a clear preference of being left-wound. For being right wound, it would have to be a completely different kind of molecule - possibly even something, that can't be made from abundant material. But don't let me disturb you with reality.

3. Collection of assumptions, but no fact.

a) "There must be a minimum time to get to a point in evolution and life on Earth needed less than that." -> Argument by ignorance.

b) "There is a way to quantize complexity and compare it by percent figures to today." -> Stomach feeling is no scientific measure.

c) "Life was already very complex in the past." -> Argument by ignorance, as I have already shown you. Life needed already 2.3 billion years from simple single cell microbe-likes (Which are no microbes, but just look similar) to multi-cell life and sexual reproduction, and possibly a fair bit much longer until you had both traits united.

 

[Linguofreak]

{{Citation Needed}}. Also, maybe the left-handed ones worked and the right-handed ones didn't, for whatever reason.

http://en.wikipedia.org/wiki/Homochirality

Still, that doesn't prove that Earth was seeded with life any more than the handedness of neutrinos proves that the weak nuclear force has an origin outside the universe.

---------- Post added at 02:43 PM ---------- Previous post was at 02:21 PM ----------

Actually not. You recite the "minimum complexity" argument of creationists

And yet he comes almost the opposite conclusion, ie, that life evolved somewhere else rather than being created locally.

 

[Urwumpe]

And yet he comes almost the opposite conclusion, ie, that life evolved somewhere else rather than being created locally.

Does not change the logical problems, but rather moves the battlefield from Earth to outer space...where did the first life come from and how did it survive uncontrolled atmospheric reentry. Or how did it get catapulted from other planets?

 

[Linguofreak]

Your three facts, as you call it, BTW, are one irrelevant fact and two unfounded assumptions - if you would be a real scientist, your academic conscience should be crying in pain.

Give him a break. His points are certainly not empirically valid, but I've seen similar arguements in serious scientific literature. So whether or not it *should* cause pain to the academic conscience, it is a proven fact that real scientists can not only make such arguements but actually *publish* them without feeling any such pain.

@ MArujo:

Your first point makes a strong (though not completely airtight) case that all life today on Earth has a common point of origin. It does not, however, establish whether that point was on Earth or off of it. Insofar as it can say anything about the location of that point, it almost more counter-indicates an origin in space than it supports it. If Earth could be seeded once, why not twice, or more?

Your second point somewhat ties in with the first point, it argues a common point of origin based on similarities, but it has its problems: Alot of opposite handed molecules (right handed for amino acids, left handed for sugars), are known to be toxic to life as it currently exists on Earth. Opposite handed life might have arisen on Earth, but if life with our handedness got a head start, the opposite handed life might simply have been poisoned to death trying to live in an our-handed ecosystem. This doesn't rule out the possibility that mixed-handed life could arise, or that life could arise that had survival mechanisms for living in an ecosystem with a different handedness, but it does indicate that one possible reason that we don't see life with different handedness is because our-handed life simply poisoned away everything else.

Your third point is the one that best supports your conclusion, but it's still not empirically airtight. You can use it to say that you think it *rather likely* that life originated somewhere other than Earth, but it can't say anything more than that. Also, aside from the fossil record, our understanding of the time evolution takes is based on a bit more than a century of study in which we have only had the biosphere of one planet to watch. Evolution could, on average, proceed much faster or slower than you think. If it's much faster, then the question becomes "why did it take so long on Earth," and your arguement falls apart. If it proceeds much more slowly, then it does become a fairly strong arguement in favor of creationism (which is why the others brought it up), and I have both heard it given and used it myself as an arguement for creationism. But no matter what you try to prove with it, it is not empirically valid and as such only states likelyhood, not proof.

---------- Post added at 03:42 PM ---------- Previous post was at 03:41 PM ----------

Does not change the logical problems, but rather moves the battlefield from Earth to outer space...where did the first life come from and how did it survive uncontrolled atmospheric reentry. Or how did it get catapulted from other planets?

Indeed it doesn't.

 

[Eagle]

Does not change the logical problems, but rather moves the battlefield from Earth to outer space...where did the first life come from and how did it survive uncontrolled atmospheric reentry. Or how did it get catapulted from other planets?

Well some microbes can be quite hardy to radiation, heat and vacuum. So I don't think its too unimaginable for one or two to survive descent in a mudeoroid. There is a meteoroid that was found in Antarctica that was believed to come from ejecta of an impact on Mars.

I guess the neat thing about astronomy is that the Universe is big enough that the unlikely has a chance to happen.

But of course, life has to originate from somewhere and abiogenesis on Earth fits Occam's Razor the best.

 

[Linguofreak]

Be careful when shaving with Occam's razor: Judgements of complexity often depend on going-in assumptions.

 

[Urwumpe]

Be careful when shaving with Occam's razor: Judgements of complexity often depend on going-in assumptions.

Exactly. But Okkhams razor does not deal with complexity at all, and should not be used that way.

It asks for the optimal explanation, to use as little expressions and dependencies as possible.