For about 40 years now, scientists have been working to recreate the primordial soup. What I mean by this is we’ve been trying to determine and recreate the original conditions that led to life on this planet. Powner et al. 2009 have managed to do just that.
We believe that life originated as RNA, a chain of nucleotides consisting of a nitrogenous base, a ribose sugar and a phosphate. These nucleotides come in two types, pyrimidines (cytosine and uracil in RNA or thymine in DNA) and purines (adenine and guanine). Using compounds that were likely present in the early atmosphere and under similar conditions (for example, under high UV radiation), researchers have observed the creation of RNA’s pyrimidines. This is a major step toward understanding the origin of life on earth.
As an aside, fairly specific conditions that were present millions of years today and are not present today were required for this experiment to work. For example, the level of UV radiation required to create the pyrimidines is probably much greater than the UV radiation on the planet today, suggesting that we may not be seeing spontaneous new life emerging anytime soon. A popular creationist argument is that scientists claim life arose spontaneously and therefore we should be seeing spontaneous life emerging all over the place. The “peanut butter argument” claims that the fact that life doesn’t spontaneously arise in the millions of jar of peanut butter that have been sold throughout the years disproves evolution.
First of all, as I said a moment ago, the conditions necessary for creating life simply aren’t present in a peanut butter jar. Second, we tend to consider the origin of life as a thing somewhat separate from evolution. As soon as RNA molecules arose, there was certainly evolution occurring as the molecules competed for resources with varying success in the primordial soup. But how these molecules arose in the first place is a matter of chemistry, not evolution. Anyway, for the sake of a good laugh, here is the argument: