Editing 3095: Archaea

{{comic
| number    = 3095
| date      = May 28, 2025
| title     = Archaea
| image     = archaea_2x.png
| imagesize = 404x412px
| noexpand  = true
| titletext = Under the two-domain system, anyone who punches you is technically an Archaean pathogen.
}}

==Explanation==
{{w|Archaea}} is one of the three main lineages (domains) of free-living lifeforms. The other two are {{w|Bacteria}} and {{w|Eukaryote|Eukaryota}}. Organisms within Archaea and Bacteria are {{w|Prokaryote|prokaryotes}}. The bacterial and eukaryotic domains each contain numerous species that cause human disease (are pathogens). However, to date, no species of Archaea has been unequivocally shown to be a human pathogen. Whether such pathogens exist, and if they do, why they are rare and have low impact, are [https://microbiologysociety.org/blog/why-dont-archaea-cause-disease.html matters of debate].

The joke in this comic is that one or more strains of Archaea, being cultivated in a laboratory, overheard a conversation among three human scientists (represented by [[Cueball]], [[Megan]], and [[White Hat]]). Perhaps taking offense at Megan's disparaging comments, the eavesdropping culture resolves to become a human pathogen. The caption reports this as "bad news" for humanity. It may turn out that they always had the ''potential'' to harm humans, but had never tried to (for any number of reasons).

Most of the species of Archaea that were known, at the time that the domain was recognized and for some time thereafter, were {{w|Methanogen|methanogens}}, cells that require anaerobic conditions for life and emit methane as a byproduct, or {{w|Methanotroph|methanotrophs}}, cells that use methane (also anaerobically) as a carbon source ("food"). Methanogens and methanotrophs are common in the guts of humans and other animals, therefore have proximity to human cells and opportunity to infect them — hence (the inappropriate anthropomorphism aside) their indignance at Megan's comment, especially since neither group contains methane "breathers". Archaea are now known from many different environments, including aerobic ones, so do not have the limited metabolic options that one might assume that they do from Megan's statement. Megan calls them "gross methane breathers" and believes they are too weird and incompetent. If the Archaea could actually understand this, no wonder they became offended and would like to prove what they could do to us.

"Archaea has" in the caption is a debatable grammar, as it denotes that a lineage (a branch of a phylogenetic tree) has become pathogenic. "Archaeans have" could have been better, but contrast with statements using "humanity is", compared with "humanity are" for the linguistic and contextual complications involved.

The title text alludes to the hypothesis that the domain Eukaryota arose from within the domain Archaea, allowing for a {{w|two-domain system}} which classifies everything into Bacteria and Archaea, with Eukaryota being included as a sub-division of Archaea. Since humans belong within Eukaryota (i.e. being not Bacteria), by extension they would belong to the Archaea split. A human attacker of another human could therefore be considered both a pathogen and an archaeon. The same would be true of an attack by any other animal, as well as an infection caused by a fungus or protist.

==Transcript==
:[Cueball, Megan, and White Hat are standing in a lab in front of a root-like phylogeny diagram, looking at it. Behind them is a desk with a microscope on it. There is a pile of items behind it and one item in front. From the plate on the microscope where the sample is, there is a star burst and a line going up to the text said by the sample.]
:Cueball: It's weird how, despite being one of the main branches of the tree of life, no Archaea species are known to cause disease in humans.
:Megan: Personally, I think it's because those gross methane breathers are too weird and incompetent to figure out how to hurt us even if they wanted to.
:Archaea sample: ''Hey!''

:[Caption below the panel:]
:Bad news: After overhearing a conversation in our lab, Archaea has finally started harming humans.

{{comic discussion}}<noinclude>

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Biology]]