The evolutionary equivalent of chicken-and-egg problem is the origin of life. The question of how did life came into being is a great(est) topic for debate and research today. There are essentially two hypothesises regarding this: first one ( “RNA world” ) says that the first molecules to be alive were RNA molecules which have both catalytic and hereditary information carrying capacity. But it is being argued that it should be highly unlikely that RNA molecules of sufficient length could have been possible because the conditions then were quite harsh.
The second hypothesis, which is gaining support these days, is called “metabolism first”. It means that the metabolic reactions preceded the genetic information carriers. The reactions occurred in self-sustaining way, each one looping around to grow into bigger and bigger cycles. Occasionally these reactions would have split into two independent reactions. There may even be evolution in these reaction mixtures as the new compounds (which can better metabolize and generate energy faster) can replace the old compounds.
As for my personal opinion, I (as of now) believe in RNA world theory. I think I will take time to ponder on “metabolism first” model of origin of life. But, anyway, both the hypothesis are challenging and worthwhile to devote one’s time on researching.
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