Aquilegia753 writes:
However, if life was random, it might be centered around some other element, like iron, or oxygen, or radon, or lead, or something.
Yes, but life isn't random. If life is to originate, it must be using something that has properties that lend it to life. So, you couldn't just randomly pick an element from the periodic table to build life out of, just as you wouldn't randomly pick a material from the hardware store to build a chair. You have to consider the properties of the material.
Carbon has many properties that cause it to be a very good building block. It has four electrons in its outer shell, allowing it to form four bonds with other atoms (or a double bond/triple bond with something). This allows it to form long chains, as in sugars and fats, plus to form a chain along with nitrogen, as in amino acids.
Oxygen has six valance electrons, so it could only form two bonds (or a double bond). Lead and radon are rare, and plus radon barely reacts with anything.
Iron is a transition metal, and as such forms complexes with things like oxygen (as in O
2 or H
2O). This is useful in some organic processes (such as binding oxygen in hemoglobin), but not particularly useful if you want to be able to make hydrophobic (water-repelling) parts of a protein. And without hydrophobic parts, the water will never 'push' the protein to fold up. Not to mention that life would have a terrible problem with rust.
Some sci-fi authors have speculated about other molecules making life, but each has their problems. You can read about some of them here:
Alternative Biochemistry
Aquilegia753 writes:
It would seem that life could appear anywhere, in any atmosphere, with any gravity, with any heat.
It might be able to, but from what we tell, life needs to have water or some other very common polar solvent that forms crystals. That might not be true, but certainly it would make things easier.
Aqiulegia753 writes:
It would also seem that there would be some other life on earth not based on carbon, but there isn't. So, either only carbon-based life was created on earth, or earth could only support carbon-based life or carbon-based life prevailed.
So, either carbon-based lifeforms were the only ones created, or they were the only ones that evolved. This isn't really good evidence for creation if evolution can also explain it, is it?
Edited by Doddy, : bbcode
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