explain xkcd - User contributions [en]

3252: Ancestral Genomes

2026-06-01T23:35:36Z

198.99.80.100: If we're not doing a warning, then I'm just deleting the link altogether. There is absolutely zero need to have a link to that page. Honestly, I'm not convinced we even need to reference Wikimedia Commons' NSFW image library, given its sinister history.

{{comic
| number = 3252
| date = May 29, 2026
| title = Ancestral Genomes
| image = ancestral_genomes_2x.png
| imagesize = 299x416px
| noexpand = true
| titletext = SUGGESTIONS FOR FUTURE RESEARCH: No further research is needed as it is frankly none of our business.
}}

==Explanation==
{{incomplete|This page was DELETED TO RESPECT THE COMIC’S PRIVACY. Don't remove this notice too soon.}}

A {{w|genotype}} is the complete genetic makeup of an individual, i.e. all of its genes. In humans, genotypes are almost always inherited from an individual’s parents; the two parents’ genotypes combine during sexual reproduction to form the genotype of the child. {{w|mutation|Mutations}} do occur, where parts of the DNA change randomly in a way that gives rise to a new genotype, and [https://www.cbc.ca/radio/quirks/october-21-2017-1.4363723/how-many-mutant-genes-does-a-person-have-1.4363741 each human has about 60 such mutations, on average,] out of about 20,000 genes. However, most mutations are "silent", i.e. not causing any visible changes. Depending on the behavior of the mutation, and if it even occurs to any gamete cells or those that produce them, it may spread throughout a population, or disappear again, or end up only being present in a certain fraction of the population. Either way, when studying a genotype, it is ''exceedingly rare'' to not arise through sexual intercourse, and impossible to spread throughout the population without it. As modern-day genetics researchers, [[Megan]] and [[Cueball]] should definitely know this fact.

Currently in the United States, topics around sex are at least partially considered taboo. This taboo most strictly covers depictions of sex and nudity in media, which are usually the domain of pornography and less mainstream art forms (e.g. nude photography). Megan defending themselves as not being “weirdos” suggests that she in fact does not want to break the taboo. In academic science however, such topics are generally part of regular scientific discussion, including depictions and descriptions that would be considered offensive in other circumstances. For example, Wikimedia Commons contains many depictions of sexual intercourse for scientific and educational purposes. While some researchers, like the ones depicted in the comic, might be offended by such “lewd” contents, most would regard them well as long as they further the research on the topic at hand. Real-world biologists or geneticists would most likely not be offended by these issues, as sexual reproduction is a common or even predominant topic in both fields. Furthermore, the obscenity of the topic (genetic distributions affected by sexual reproduction) is very low in comparison to fields that deal with intercourse directly. This view seems to be shared by the off-screen commenter in the comic.

What is more problematic, and also addressed by the researcher’s comments, is the privacy of the individuals in the population under examination. Namely, using such data, it might be possible to figure out who had intercourse with whom, possibly reducing the timeframe to within less than a year based on the offspring’s age. However, since the analysis depicted likely takes place over many generations within a population, and is done on historical data, it is likely that the vast majority of the people whose genomes were analyzed are no longer alive. This is supported by the description of the population as “ancestral”. Beyond a certain point, even private data pertaining to deceased people is no longer considered sensitive, as it becomes the subject of history. The only problematic part is the ancestral information for living individuals, which is indeed worthy of protection—but not for the reasons given.

The title text is a reference to [[2268: Further Research is Needed]]. This one is based on the fact that most scientific papers contain a section suggesting future research avenues. This is done in the hope that other researchers will pick up where the authors have left off, or to announce the author’s own intentions for follow-up work. However, in this case, Megan and Cueball are both averse to the idea of future research, since as established they don’t think it’s appropriate to do so, which is ironic given the reason for the section.

Genetics and sex have also appeared in [[830: Genetic Analysis]]. Presenting outlandish or plain bad/incorrect research has been a common topic, such as in [[3129: Archaeology Research]] and [[3000: Experimental Astrophysics]].

If the researcher had access to the time machine from [[3251: Time Machine Conversation|the previous comic]], they would not need to rely on techniques such as admixture. Though personally using the time-travel ability to manifest oneself at the time and place of ''every'' birth and/or conception event to obtain the data necessary to accumulate the same (or better) ancestral information ''would'' probably mean a series of very intrusive invasions of privacy that might well be considered as the actions of a weirdo.

==Transcript==
:[Cueball and Megan are shown, with Megan using a pointer stick to point at a diagram on a poster. The diagram features tree/root structure with a single node at the top end, branching solid lines leading to more nodes across several levels in most cases, but with at least one node that does not propogate this way and some dotted lines linking down from some branches into other ones. The increasingly branching lower tracks becoming so dense that it almost looks like dark triangles at the bottom of the diagram's last obvious bifurcations. Small and unreadable labels/symbols feature next to most linking lines, and more extensive (but still totally unreadable) information is placed below each of the lowermost 'triangular' terminating clumps.]
:Megan: Our admixture analysis showed that these genotypes arose in the ancestral population almost entirely through sexual intercourse.
:Megan: Upon realizing this, we of course promptly deleted all our data.
:Off-screen voice: What? Why??
:Megan: We're not '''''weirdos!'''''
:Megan: Jeez, give these people some privacy!

{{comic discussion}}<noinclude>
[[Category:Biology]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Sex]]

3252: Ancestral Genomes

2026-06-01T21:05:35Z

198.99.80.100: /* Explanation */ NSFW warning for the unwary

{{comic
| number = 3252
| date = May 29, 2026
| title = Ancestral Genomes
| image = ancestral_genomes_2x.png
| imagesize = 299x416px
| noexpand = true
| titletext = SUGGESTIONS FOR FUTURE RESEARCH: No further research is needed as it is frankly none of our business.
}}

==Explanation==
{{incomplete|This page was DELETED TO RESPECT THE COMIC’S PRIVACY. Don't remove this notice too soon.}}

A {{w|genotype}} is the complete genetic makeup of an individual, i.e. all of its genes. In humans, genotypes are almost always inherited from an individual’s parents; the two parents’ genotypes combine during sexual reproduction to form the genotype of the child. {{w|mutation|Mutations}} do occur, where parts of the DNA change randomly in a way that gives rise to a new genotype, and [https://www.cbc.ca/radio/quirks/october-21-2017-1.4363723/how-many-mutant-genes-does-a-person-have-1.4363741 each human has about 60 such mutations, on average,] out of about 20,000 genes. However, most mutations are "silent", i.e. not causing any visible changes. Depending on the behavior of the mutation, and if it even occurs to any gamete cells or those that produce them, it may spread throughout a population, or disappear again, or end up only being present in a certain fraction of the population. Either way, when studying a genotype, it is ''exceedingly rare'' to not arise through sexual intercourse, and impossible to spread throughout the population without it. As modern-day genetics researchers, [[Megan]] and [[Cueball]] should definitely know this fact.

Currently in the United States, topics around sex are at least partially considered taboo. This taboo most strictly covers depictions of sex and nudity in media, which are usually the domain of pornography and less mainstream art forms (e.g. nude photography). Megan defending themselves as not being “weirdos” suggests that she in fact does not want to break the taboo. In academic science however, such topics are generally part of regular scientific discussion, including depictions and descriptions that would be considered offensive in other circumstances. For example, Wikimedia Commons contains [https://commons.wikimedia.org/wiki/Category:Human_sexual_activity many depictions of sexual intercourse] (HIGHLY NSFW LINK) for scientific and educational purposes. While some researchers, like the ones depicted in the comic, might be offended by such “lewd” contents, most would regard them well as long as they further the research on the topic at hand. Real-world biologists or geneticists would most likely not be offended by these issues, as sexual reproduction is a common or even predominant topic in both fields. Furthermore, the obscenity of the topic (genetic distributions affected by sexual reproduction) is very low in comparison to fields that deal with intercourse directly. This view seems to be shared by the off-screen commenter in the comic.

What is more problematic, and also addressed by the researcher’s comments, is the privacy of the individuals in the population under examination. Namely, using such data, it might be possible to figure out who had intercourse with whom, possibly reducing the timeframe to within less than a year based on the offspring’s age. However, since the analysis depicted likely takes place over many generations within a population, and is done on historical data, it is likely that the vast majority of the people whose genomes were analyzed are no longer alive. This is supported by the description of the population as “ancestral”. Beyond a certain point, even private data pertaining to deceased people is no longer considered sensitive, as it becomes the subject of history. The only problematic part is the ancestral information for living individuals, which is indeed worthy of protection—but not for the reasons given.

The title text is a reference to [[2268: Further Research is Needed]]. This one is based on the fact that most scientific papers contain a section suggesting future research avenues. This is done in the hope that other researchers will pick up where the authors have left off, or to announce the author’s own intentions for follow-up work. However, in this case, Megan and Cueball are both averse to the idea of future research, since as established they don’t think it’s appropriate to do so, which is ironic given the reason for the section.

Genetics and sex have also appeared in [[830: Genetic Analysis]]. Presenting outlandish or plain bad/incorrect research has been a common topic, such as in [[3129: Archaeology Research]] and [[3000: Experimental Astrophysics]].

If the researcher had access to the time machine from [[3251: Time Machine Conversation|the previous comic]], they would not need to rely on techniques such as admixture. Though personally using the time-travel ability to manifest oneself at the time and place of ''every'' birth and/or conception event to obtain the data necessary to accumulate the same (or better) ancestral information ''would'' probably mean a series of very intrusive invasions of privacy that might well be considered as the actions of a weirdo.

==Transcript==
:[Cueball and Megan are shown, with Megan using a pointer stick to point at a diagram on a poster. The diagram features tree/root structure with a single node at the top end, branching solid lines leading to more nodes across several levels in most cases, but with at least one node that does not propogate this way and some dotted lines linking down from some branches into other ones. The increasingly branching lower tracks becoming so dense that it almost looks like dark triangles at the bottom of the diagram's last obvious bifurcations. Small and unreadable labels/symbols feature next to most linking lines, and more extensive (but still totally unreadable) information is placed below each of the lowermost 'triangular' terminating clumps.]
:Megan: Our admixture analysis showed that these genotypes arose in the ancestral population almost entirely through sexual intercourse.
:Megan: Upon realizing this, we of course promptly deleted all our data.
:Off-screen voice: What? Why??
:Megan: We're not '''''weirdos!'''''
:Megan: Jeez, give these people some privacy!

{{comic discussion}}<noinclude>
[[Category:Biology]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Sex]]