3046: Stromatolites

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Stromatolites
If only my ancestors had been fortunate enough to marry into the branch of the bacteria family that could photosynthesize, like all my little green cousins here.
Title text: If only my ancestors had been fortunate enough to marry into the branch of the bacteria family that could photosynthesize, like all my little green cousins here.

Explanation

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Created by THE MISSING LINK'S OSTRACIZED ANCESTOR - Please change this comment when editing this page. Do NOT delete this tag too soon. If you can address this issue, please edit the page!

This comic makes fun of claims to 'special' ancestry, such as some old royal family or similar, that may be made after doing research on a family tree site. These services allow the user to input the names and other information of family members and cross reference with various documents to trace lines of descent. Often, those who find a connection to historically significant individual are quite excited about this, and may feel that it somehow makes them special. However, in reality, once you go back more than a few generations there will be many thousands of such connections, and once you get back more than a thousand years or so, anyone you could be related to will also be related to pretty much everybody else still alive in some way or other.

While out for a walk, Beret Guy is explaining to Cueball how he has been on such a site and kept clicking back until he found an ancestor from "a few billion years back". These services typically do not allow the user to track their familial history prior to written records[citation needed] (although some do provide genetic sequencing which allows for more information to be acquired, but this isn't accurate enough to track on a wide scale individual people who lived before such technology existed), but with his strange powers it is no wonder that Beret Guy could make this work! This would also explain how he is able to do all the clicks needed to go back that far in the past, as at even at a rate of 10 to 15 clicks per second, it would still take thousands of years—maybe even more due to how fast cells can reproduce—to do enough clicks.

Beret Guy found out that he is related to Stromatolites. They are layered sedimentary formations created by microorganisms, predominantly the oxygenic-photosynthetic cyanobacteria. The organisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats" (Cueball calls them bacterial mats). A succession of these mats through time forms the layers ("stromata") characteristic of both fossil and modern stromatolites. Some fossil stromatolites in Australia from 3.48 billion years ago contain the oldest undisputed evidence of life on Earth, though people have also claimed other, older evidence for this record. Since this is some of the first life on Earth it is basically a given that all life that came after (not even just all humans) is related. Beret Guy only claims he is related to their cousins and that it is from their cousin bacteria that he got his mitochondria. His aside that he also got his cell nuclei in this way is odd, as, according to the leading contemporary theory, the ancestral archaeon ("my archaean ancestors") themselves contributed the nucleus to the original eukaryotic cell. In this model, both the archaeon and the alpha-proteobacterium were endosymbionts in a third cell, which is not consistent with Beret Guy's claim that the mitochondrion began as an archaeon's endosymbiont. Perhaps all that clicking addled even Beret Guy's brain. Anyway, he is not claiming to be a direct descendant from [the cyanobacterial component of] stromatolites, which makes sense since they can photosynthesize, and as he mentions in the title text, he cannot!

Cueball asks if he would like to contact his distant relatives, since there are still living stromatolites today (or at least something very similar to those from billions of years ago). But Beret Guy imagines they are busy so he will not bother them. When asked by Cueball what he would use his newfound knowledge for, he lies down on the hill they have climbed to bask in the sun. Because as he says Lying on a hill in the warm sun is an old family tradition. This is basically the only thing stromatolites can do, but they are doing it all the time and could thus be said to be busy with this. It seems, however, like Beret Guy is going to enjoy this tradition.

In the title text Beret guy muses about how great it would have been if his distant relatives had married into the branch of the bacteria family that could photosynthesize... And then refers to the grass he is now lying on as my little green cousins here. If this had happened he would either have been able to lie on the hill without eating since he would be able to photosynthesize getting energy directly from the sun (instead of eating some of his small green cousins closer relatives). Or else he would actually have been a plant instead.

Transcript

[Cueball and Beret Guy, seen from a far in silhouette are walking up a grassy hill.]
[They continue walking up the hill, reaching its grassy summit. Now with a standard white background. Beret Guy is a bit ahead of Cueball.]
Beret Guy: I learned something today.
Beret Guy: I went on one of those family tree sites and kept clicking back, and it turns out I'm related to stromatolites!
[Closeup on Cueball. Beret Guy's reply comes off-panel from a starburst on the right edge of the panel.]
Cueball: The bacterial mats?
Beret Guy [off-panel]: Yeah! A few billion years back, on my mitochondria's side.
[Cueball and Beret Guy standing on the top of the grassy hill facing each other. Berety Guy holding a hand out towards Cueball.]
Beret Guy: My Archaean ancestors absorbed some bacteria that were cousins of stromatolites. That's how I got mitochondria.
Beret Guy: Cell nuclei, too.
[Cueball is standing behind Beret Guy who is now sitting down in the grass leaning back on one arm with the other arm resting on his bend knee.]
Cueball: I think there are still living stromatolites. You could get in touch.
Beret Guy: Nah, they're probably busy. I don't want to bother them.
[Cueball is sitting behind Beret Guy who is now lying down, both again shown in silhouette from a far, revealing they are on the top of the grassy hill.]
Cueball: So what are you going to do with this knowledge? Nothing?
Beret Guy: Lying on a hill in the warm sun is an old family tradition.


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Discussion

Yay, another Beret Guy appearance! 42.book.addictTalk to me! 03:46, 4 February 2025 (UTC)

He's unusually sage this time. ;) --172.71.160.32 22:00, 7 February 2025 (UTC)

I'm not sure if I'm trying to remember Bloom County and the penguin (Opus) or Snoopy by Schulz because of the last panel. Shrug. Prolly both. Warm is good. 172.70.175.208 06:08, 4 February 2025 (UTC)

Add Zonker to this list? 108.162.245.39 17:29, 4 February 2025 (UTC)
Zonker Harris, yes! 172.70.175.106 18:16, 4 February 2025 (UTC)

How can anybody be related to rock formations? Stomatolites are not organisms, they are the product of organisms. 141.101.105.88 08:12, 4 February 2025 (UTC)

This might be one of Randall's weaker offerings in terms of scientific accuracy. I think that "stromatolites" as here used refers to the cyanobacterial component of stromatolites, which is the component detected in ancient fossils and is the one responsible for oxygen-evolving photosynthesis (responsible for what was perhaps the first global environmental catastrophe - an element of ancestry of which it might be wise not to boast). Modern stromatolites have both cyanobacteria (ancestors of plastids) and alpha-proteobacteria (ancestors of mitochondria) in their microbial mats, and it's reasonable to assume that alpha-proteobacteria were present in the fossils. So the "cousins" would be of cyanobacteria in the stromatolites, not the stromatolites themselves (in which both were, presumably, cohabiting). Beret Guy also appears to be confused about the proposed sequence of events leading to the origins of mitochondria and eukaryotic cell nuclei. 108.162.245.39 17:29, 4 February 2025 (UTC)
I've seen the surviving microbial mats in Australia referred to as "stromatolites" as well.Nitpicking (talk) 12:39, 4 February 2025 (UTC)

I wonder if he is related to any specific dinosaurs or whether he bypassed that branch of the tree completely. 09:48, 4 February 2025 (UTC)

I think there's a joke (or at least a reference) here about the relatedness of life. All currently-known organisms are related by descent from a common ancestor, which in English makes us all cousins, of various distances. Mitochondria in plants and animals, for instance, must descend from the same bacterium-like organism that became an endosymbiont in a proto-eukaryote.Nitpicking (talk) 12:39, 4 February 2025 (UTC)

Since mitochondria and chloroplasts were both originally distinct organisms that were absorbed into the host cells, that makes most modern life descendants of cannibals. Barmar (talk) 15:37, 4 February 2025 (UTC)
By that logic, eating pretty much any food except salt (and maybe dairy?) is cannibalism. 172.68.70.87 16:09, 4 February 2025 (UTC)

I immediately thought of Fabulous Pedigree, which does include ancestry (and side-branches) going back to (and past) mitochondria, though from a quick check it doesn't seem to specifically include stromatolites. Obviously the listing has lots of (mostly implied) gaps. --162.158.217.72 13:55, 4 February 2025 (UTC)

Beret Guy is emulating Pooh-Bah in The Mikado: "I can trace my ancestry back to a protoplasmal primordial atomic globule."172.69.33.190 19:07, 4 February 2025 (UTC)NickM

I've added a bit about the length of time it would need to take to click that far back in the past. I'm sure I have got the amount out by several orders of magnitude, so I would appreciate it if anyone fancies a go at estimating how long Beret Guy would have taken. 172.71.241.27 10:49, 4 February 2025 (UTC)

2608: Family Reunion estimates about 50 billion generations to the MRCA with plants; this would have taken about a century at a speed of 15 clicks per second. Bacteria reproduce extremely fast - or at least modern ones do - which could easily add a few trillion generations (and a few thousand years of clicking) on the bacterial side of the ancestry. In other words, "thousands of years" is likely an overestimate but not that much of one. (Obviously the time becomes very feasible if Beret Guy used a site that summarized the ancestry.) --162.158.111.134 20:25, 4 February 2025 (UTC)
Typically the way it works is you work back so far and then find a connection to a pre-existing tree, so he wouldn't need to go very far back to get to a tree that covered all modern humans, provided someone had already done the work beyond that point before him.172.70.91.29 10:27, 5 February 2025 (UTC)
...this would have required someone else to have (give or take a small proportion of BG's generations, due to mismatches) done the same work as BG and then the work that we're now excusing BG as having not done. Hard to know how that would happen
Theoretically, if the website/database was live at the point of the point of Most Recent Common Human Ancestor, that individual could establish the 'further back' (ready for BG's search to find them and latch on to it), or at least as far back as a prior MRCA that also had the website hand to pre-establish yet further back (for as many further iterations as necessary), which might even be tied in with how sufficiently(?) detailed core family tree data. But then BG's Special Powers is reliant upon finding a website that actually predates the web ('90s) and the internet ('70s), and networked databases ('60s), and programmable computers ('40s), and keyboards (let's say the 1700s), and mice (the paleocene, who would have probably prefered using gopher), that was somehow still interacted with in order to set things up ready for BG's own (more trivial) direct miracles. 172.70.163.167 13:10, 5 February 2025 (UTC)
It would have required someone else to create it, but not necessarily by repeated clicking - they could have used some automated process to do it that would speed things up substantially. Of course, there is then a problem of where the data comes from to feed that process, but once you start worrying about that you've got a more fundamental issue than how quickly he (or anyone else) can click things.141.101.98.187 17:05, 5 February 2025 (UTC)

Six paragraphs should be four. Too much non-explanatory and otherwise pointless digression. I'm sure the people who write it don't realize how much it turns off people coming here to read an explanation. 172.70.215.72 11:03, 5 February 2025 (UTC)

Which two paragraphs? And we already have long paragraphs, but if we joined two pairs together then you'd be happy? Counting just paragraphs is not a good measure, whatever you really mean. And I guarantee that most of what you'd want to remove is only subjectively unnecessary.
Personally, I'd like the existing six to be tightened up (somehow, yet to go through them to work out how), but each has good points in. Could you be happier with just less loquacious verbosity, but presenting the same general scope in less space? (Probably not, but depends exactly which elements are "pointless digression" in your POV...) 172.70.163.167 13:10, 5 February 2025 (UTC)
Tolkien wrote this about critique of his Lord of the Rings: "... for I find from the letters that I have received that the passages or chapters that are to some a blemish are all by others specially approved." In the absence of a polling system, how are folk to assess the significance of individual comments? One could do a Musk run through the text, roiling the explain-xkcd community and thereby creating a disturbance in the Force, without actually improving the read. The uncharacteristically poor handling of the science underlying the comic complicates efforts to achieve conciseness and clarity. 172.71.146.32 14:07, 5 February 2025 (UTC)

Parody? (with an evolutionary theory). Several news sites (tabloids?) occasionally write news about people being extremely distantly related to (e. g. 17th-order cousins and above) each other. This comic takes it to the extreme case of being related to the bacteria that created stromatolites. The evolutionary theory shown in the comic is that every organism (Bacteria and Archaea s. l.) is related. 172.70.35.190 07:07, 6 February 2025 (UTC)

As already covered by a prior comic, we have (nth-)cousins all over the place. A lot of store was set by Obama being 10th cousins with Bush Jr, but also 15th cousin to Churchill and 9th cousin to Brad Pitt (with Hillary Clinton being 9th cousin to Angelina Jolie).
But cousins is fairly 'easy' (so long as the records, or reasonable presumptions, exist), as there steadily become so many potential common ancestors by various different branches that you might easily find a fathers'-sides co-ancestry point just by having surname clues (to bridge any actual gaps in the paperwork) where a more direct mothers'-sides relationship might be lost. (That's the official, ancestry, of course... Blood descent could well depart significantly from that, whether or not anyone (who 'matters') thinks/'knows' differently at the time.)
By the same measure, you have also found the (possibly!) most recent common ancestor... You know there must be one, of course, but placing them is subject to all the issues of lack of records (or misdirecting ones) giving you problems. But Beret Guy seems to think his efforts are accurate. And, knowing his expectation-based powers, he probably has. No real parody of evolution, just simplifying away the necessarily messy parts of its long-term study. 172.70.91.11 14:40, 6 February 2025 (UTC)

Did anyone else besides me read "Stromatolites" like a Greek name, like Socrates? Mathmannix (talk) 02:01, 13 February 2025 (UTC)

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