Evolution and the genesis of life

[alteregoivy]

Hey, guys, I think I need a little help...

I know how evolution works and why it works. I also know it's been proven that you can make very complex protein compounds just by simulating the conditions of Earth at the dawn of our planet.

What I don't understand is what evidence (if any) there is to prove that DNA can arise from those conditions and begin to self-replicate. I also don't understand how DNA can then jump to making a single-celled organism.

This trips me up every time I'm in a conversation with a Creationist. Any help?  

[Labtech Soosh]

Not ALL forms of DNA can self replicate.

Evidence was formed when a man was testing his hypothesis by shocking a mixture of chemicals that were only available on primitive earth with electricity.

The chemicals are as followed

Quote:

-Methane (CH4)

-Ammonia (NH3)

-Water (H2O)

-Hydrogen (H2)

The results were amino acids, the building blocks of proteins. It was later discovered that other energies also can excite gases and produce all 20 amino acids.

Quote:

-Electricity

-Ultraviolet light

-Heat

-Shock

DNA doesn't jump to making a single-celled organism, it's rather created chemically and if odds are in favor it might clump together to create some sort of biological mass of goo.

EDIT:

http://www.wisegeek.com/what-is-primordial-soup.htm

Quote:

The process would have been very gradual, as the acids increased in complexity and joined with each other in new ways. As living organisms emerged, they also had a direct impact on the environment and subsequently their own evolution, especially when organisms started photosynthesizing and producing oxygen as a byproduct. The production of oxygen changed the atmosphere so radically that the conditions which first created life on Earth would never be able to be replicated in the modern natural environment.

 

[dl1371]

i think they did an experiment once that duplicated the enviroment of pre-life earth, and they created some organic compounds from the experiment that would eventually lead to DNA
i forgot what it was called though sweatdrop
sorry  

[Labtech Soosh]

dl1371

i think they did an experiment once that duplicated the enviroment of pre-life earth, and they created some organic compounds from the experiment that would eventually lead to DNA
i forgot what it was called though sweatdrop
sorry

Primordial Soup theory.

See my post above for details.

 

[alteregoivy]

Okay, I knew about proof for creating proteins and such. I guess it was the process from random group of proteins to living, self-replicating organism I didn't understand. Thanks for the info. Though I still don't think I could effectively express the argument in debate. sweatdrop  

[Lethkhar]

alteregoivy

Okay, I knew about proof for creating proteins and such. I guess it was the process from random group of proteins to living, self-replicating organism I didn't understand. Thanks for the info. Though I still don't think I could effectively express the argument in debate. sweatdrop

The thing that you need to remember is that there really is no fine line for what constitutes life and what doesn't. I don't think there's an specific part of that whole process of abiogenesis where anyone would be able to pinpoint "That is life!". We can't even figure out viruses, which evolved from the same things we did, so how could we figure out the biological status of a bunch of goop?  

[MiniSiets]

alteregoivy

I know how evolution works and why it works. I also know it's been proven that you can make very complex protein compounds just by simulating the conditions of Earth at the dawn of our planet.

Just being a little nitpicky here, but they aren't really "complex" protein compounds by my understanding. The Miller-Urey experiments simply demonstrated that organic matter (amino acids and the building blocks of life) can be produced from previously inorganic matter when applying electricity to certain chemicals under the right conditions (likely the same conditions that Earth used to be like). This is a huge step in developing a workable theory on abiogenesis (the origins of life), but we still have yet to fully create life from scratch. Now we just need to find a way to get these building blocks working together.

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What I don't understand is what evidence (if any) there is to prove that DNA can arise from those conditions and begin to self-replicate.

The important thing to recognize here is that none of this needs to be proven in order to demonstrate evolutionary theory as valid. There is already an overwhelming heap of evidence that shows that evolution is occurring now and has been occurring for a long time. How the process first started is irrelevant and unnecessary with regards to verifying the theory. If a creationist keeps insisting that it is necessary to point out how it first started in order to prove it, then you can simply point out then that the creationist must not believe that the moon exists since no one really knows where it came from and how it fell into Earth's orbit.

This is a common tactic by fundamentalists. The creationist is basically conflating two different things: Abiogenesis and Evolution. Evolution addresses how life has diversified over time, NOT the origins of life.

Quote:

I also don't understand how DNA can then jump to making a single-celled organism.

DNA is fairly complex and doesn't just form out of the blue. Most scientists believe that more primitive and strictly RNA-based organisms like certain forms of bacteria were likely the first living organisms. They were not like other single-celled organisms that we have now which are modern eukaryote cells with an endoplasmic reticulum, Golgi apparatus, and various organelles. It wasn't until later when DNA was acquired and developed, and since DNA is more stable than RNA, this is what allowed more complex organisms to form. Beyond that, I don't know any of the specifics or details of how it happens, so you'll probably need to pick up a biology book that talks about the origins of self-replication if you want anything more. sweatdrop  

[alteregoivy]

MiniSets, thank you for the in-depth explanation! I really appreciate it; it helped me understand a lot. blaugh  

[Artto]

You may want to look at this video:
http://www.youtube.com/watch?v=U6QYDdgP9eg