But evolution doesn't say that living things just jumped together like that. Living things gradually developed bit by bit. An organic molecule or living thing made of organic molecules, based on carbon compounds, would gradually change, through random mutation guided by non-random natural selection.
Natural selection is the tendency to survive and reproduce due to having the right characteristics.
Survival and reproduction are the result, not the definition, of fitness. The combination of chance modifications plus the filtering effect of natural selection produces a genuinely creative system that allows new and novel properties to emerge. Carbon is an atom that naturally and readily forms chains into other compounds, including the protein sequences that make the DNA-RNA molecules that male up living things on earth. Anti-evolutionists grossly misstate the difficulty of these compounds forming in nature. They are wrong in their assumption that all possible combinations of atoms must be included in calculations of probability of this.