baby-2
Explanation
The comic depicts a conversation between two fish -- an adult and a young one. The adult fish says, "Look, Billy, if we go on land to have babies, no way will my dad ever find out." The young fish declines: "Not even for me?" In the final panel, set "later," a fish on land is asked by a human, "Dad, why did vertebrates go to live on land?" The fish responds, "Because life is beautiful."
The joke plays on the evolutionary transition of vertebrates from sea to land, one of the most significant events in the history of life on Earth. Rather than attributing this monumental shift to any grand biological or ecological reason, the comic imagines it originated from a fish sneaking onto land to have babies without its parents knowing -- essentially a teenage rebellion scenario. The punchline "because life is beautiful" is the sanitized, noble-sounding cover story that gets passed down through generations, hiding the embarrassingly mundane (and hilariously relatable) real motivation. The humor lies in applying the universal human experience of teenagers hiding things from their parents to a massive evolutionary event, and in the contrast between the lofty official explanation and the petty actual cause.