Gates
Explanation
The Joke
A speaker (possibly a professor or tour guide) stands before a group explaining: "See, the microbes are just carefully-evolved nanobots, but generally, gene-edited our venus fly-trap rolling nano... etc." A listener interjects "What is it?" and another says "You okay, Steve?" Then someone in the group blurts out: "I just suddenly... I ever wonder if maybe the entire world isn't oriented around us in particular?" The final panel shows a large wall with a gate, and someone being thrown out with a voice saying "AND STAY OUT!"
The comic plays with the idea that humanity's entire understanding of the natural world might be a carefully curated display -- essentially a theme park or exhibit designed for humans. When one person has the epiphany that maybe the world is not actually oriented around humans in particular, he is immediately ejected, as if he has broken the fourth wall of a cosmic Truman Show.
The Humor
The humor comes from the sudden shift from a mundane science lecture to an existential revelation, followed by the absurd visual of someone being physically thrown out of reality for catching on. It satirizes both human anthropocentrism (the assumption that everything in nature exists for our benefit or observation) and conspiracy-theory thinking, while also playing with the philosophical concept of solipsism. The punchline suggests that the one person who questions the human-centered narrative is treated as a threat to the entire operation, much like a zoo animal that figures out its enclosure is artificial.