Gregory's Server3. Zoom in further on figure 2. Fig 2 says "The ocean has lot's of bio-luminescence, but it's less common on land. Creatures that glow are pretty rare here."
4. Zoom out to both figures. Fig 2 says "So it's not some niche whose exploitation was inevitable. If insects hadn't stumbled on their fatty acid enzyme trick earth just wouldn't have fireflies. Ooh, look! Their starting!"
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@xkcdbot
5. (panel is below the first 4 and equals them in total width) Zoom out to two figures, with stars visible overhead and the shadows of grass and trees illuminated by tiny pin pricks of light from fireflies. It is much more detailed and lyrical than the usual drawings. Fig 1 says "I'm glad we got a planet that has these. Fig 2 says "Yeah, it's a good one."
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