Shadow Biosphere
Shadow Biosphere
[Cueball and Megan are standing facing each other. A shadowy figure is behind Megan.] Shadowy figure: These days most of our funding comes in from the shadow biotech industry. Megan: Did you hear something? Cueball: I think it's the wind.
[Caption below the panel:] The shadow biosphere exists, but if you study it, you become a shadow biologist.

A shadow biosphere is a hypothetical microbial biosphere of Earth that uses radically different biochemical and molecular processes than currently known life. Although life on Earth is relatively well-studied, the shadow biosphere may still remain unnoticed because the exploration of the microbial world targets primarily the biochemistry of the macro-organisms.
Because organisms based on RNA would not have ribosomes, which are usually used to detect living microorganisms, they would be difficult to find in normal circumstances.
The comic suggests that this hypothetical biosphere exists, and its study is funded by "shadow biotech" corporations. The field would be called "shadow biology", so people that study it would be "shadow biologists". However, this is reinterpreted to mean "shadow" biologist, meaning that anyone that studies it becomes undetectable. A "shadowy" figure, presumably a shadow biologist, is telling this to Megan and Cueball , but they are not shadow biologists and can't hear him.
The title text references desert varnish , an orange-yellow to black coating found on exposed rock surfaces in arid environments, which has been suggested as a potential candidate for a shadow biosphere. Unless a building was made with already-varnished rocks, it would be impractical to cover a building in desert varnish (it forms naturally on rocks over thousands of years). Ignoring its impracticality, the joke is that if a building were covered in desert varnish, it would supposedly be invisible to biologists who don't study the shadow biosphere.
[Cueball and Megan are standing facing each other. A shadowy figure is behind Megan.] Shadowy figure: These days most of our funding comes in from the shadow biotech industry. Megan: Did you hear something? Cueball: I think it's the wind.
[Caption below the panel:] The shadow biosphere exists, but if you study it, you become a shadow biologist.
