Thread: Origin of life problem

Hi every one! I was wondering something about what scientific are telling about the origin of life on earth. They think that life has start in the ocean (or in water I think) near some kind of volcano. The chemistry there has made the first cell and then it has multiply. So today every living things have the same source of DNA (Whay I mean it's we can link all life on earth by there DNA). So, maybe I'm missing a piece of the puzzle there but if scientific are telling us that, don't you think we should have more than only one DNA source? If life were create by the help of chemical and heat in water, its should has spread from differents places on earth through these billions of years. So maybe life came from another place (But again how did life start on there place) or if life has start on earth we could tell that it's very very rare. What are your ideas about that. (sorry I did not find the way to do an ENTER to make paragraph (it's block) and also sorry for my English writing it's not my first laguage. Have a nice day!

You have to remember that life is part of its own environment.

The best example I can give you is from the history of technology. The Ford "Model T" was one of the first automobiles, manufactured on an assembly line. Ford sold lots of these cars. Compared to a modern automobile it was a really pathetic automobile. You would never be able to sell such an automobile if you made one today. Nobody would want it.

It's similar with life forms. The first life form was pathetic. Any modern life form today would easily eat it, or crowd it out, or otherwise kill it.

For this reason, original life forms don't emerge any more. They can't compete with modern life forms.

Originally Posted by salvage911

Hi every one! I was wondering something about what scientific are telling about the origin of life on earth. They think that life has start in the ocean (or in water I think) near some kind of volcano. The chemistry there has made the first cell and then it has multiply. So today every living things have the same source of DNA (What I mean it's we can link all life on earth by there DNA). So, maybe I'm missing a piece of the puzzle there but if scientific are telling us that, don't you think we should have more than only one DNA source? If life were create by the help of chemical and heat in water, its should has spread from different places on earth through these billions of years. So maybe life came from another place (But again how did life start on there place) or if life has start on earth we could tell that it's very very rare. What are your ideas about that. (sorry I did not find the way to do an ENTER to make paragraph (it's block) and also sorry for my English writing it's not my first language. Have a nice day!

Until we can discover life not on planet Earth, and are able to examine it's DNA, all we can do is speculate about it's origin. I like to think that anywhere life can exists that it does or will exists at some time. I am assuming all life needs liquid water at least life as we know it. Right now I don't want to put much time into thinking about any possible non-water based life.

In my opinion, DNA was created when certain proteins and amino acids combined due to heat and chemicals when the world was first created. As time went by, it split off into different ways and evolved into the DNA of today.

Originally Posted by Drew McMahon

In my opinion, DNA was created when certain proteins and amino acids combined due to heat and chemicals when the world was first created. As time went by, it split off into different ways and evolved into the DNA of today.

I'm somewhat sure if we ever discovered off world DNA, it would have some characteristics that would easily identify it as not of this Earth. Where as all DNA on this planet has a great deal in common that will always mark it as from Earth. If that's true it might help ID the origin of life, or if it's more related than expected, that could also, help ID the origin of life. Again time will tell.

Originally Posted by salvage911

They think that life has start in the ocean (or in water I think) near some kind of volcano.

Those deep sea vents are interesting because they prove life can thrive in extreme environments we'd thought too toxic. They approximate the conditions on Earth when life began... which is different than saying life began just there. The first organisms would be extremophiles by today's standards.

Originally Posted by salvage911

So today every living things have the same source of DNA (Whay I mean it's we can link all life on earth by there DNA). So, maybe I'm missing a piece of the puzzle there but if scientific are telling us that, don't you think we should have more than only one DNA source?

I have read some interesting articles about attempts to find other parallel forms of life on Earth. One problem is that we might not recognise them: if they use a different DNA code, or don't use DNA at all, they might not be picked up in surveys of micro-organisms in soil or water.

I think it is generally assumed that the reason that all the life we see around us has a common ancestor is simply competition: if there were different forms of primitive proto-life, then one would have eaten and/or out-competed the other early on. The same argument applies to why we don't see new forms of life arising now in the same environments: any chemical mistures interesting enough to ultimately develop life would also be a good source of food for existing life!

Originally Posted by Pong

Those deep sea vents are interesting because they prove life can thrive in extreme environments we'd thought too toxic. They approximate the conditions on Earth when life began... which is different than saying life began just there.

One of the interesting lines of evidence is that these vents provide large numbers of free protons (hydrogen ions) as an energy source. The idea is that existing biochemical processes could have originated to make use of that.

" any chemical mistures interesting enough to ultimately develop life would also be a good source of food for existing life!"

Yes, and heres a bit of additional conjecture/supposition; there might also have been a number of complex organic molecules that were not DNA per say that existed in parallel but nonetheless available as pre proto-life building blocks that are no longer present in noticeable quantities (if these were digested by bacteria, etc). A number of structures may have had different generation mechanism in early earth, before these were absorbed and integrated into proto-life molecules/structures, which may have then been eventually able to replicate these add-ons/add-hoc structures without needing the initial external mechanisms. A bit like cells probably integrated mitochondria, proto-life may have integrated structures of separate origins. If this is the case, then several different environments may have contributed in different ways in generating the molecules required for protolife structures, and if so, then experiments in which you mix X and Y molecules in specific conditions may not produce proto-life structures (let alone life as we know it now).