Wikipedia:Reference desk/Archives/Science/2021 May 8

= May 8 =

difference between social parasites and adelphoparasitism?
I was reading the wikipedia page on Parasitism and got confused: what exactly is the difference between social parasitism and adelphoparasitism? both seem to involve parasitism of a species closely related to the parasite so I don't understand what the difference is if there is one and I know that people aren't supposed to discuss the topic on the talk page to I thought here would be a good place to ask Feralcateater000 (talk) 14:35, 8 May 2021 (UTC)
 * Hi, I'm a bit confused as well. I think whoever wrote the adelphoparasitism section didn't quite reflect the cited sources properly. Taking some definitions from the first,
 * "adelphoparasite n. [Gr. adelphos, brother; para, beside; sitos, food] (ARTHRO: Insecta) A heteronomous hyperparasitoid."
 * "heteronomous a. [Gr. heteros, different; nomos, usage] Having unlike segments; differing in development or function.
 * "hyperparasite n. [Gr. hyper, above; parasitos, one who eats at the table of another] An organism parasitic upon another parasite."
 * "heteronomous hyperparasitoid (ARTHRO: Insecta) In Hymenoptera, a species in Adelinidae in which the female develops as a hyperparasitoid of one host, while the male develops as a normal parasitoid on another host; an adelphoparasite. see diaphagous parasitoid, heterotrophic parasitoid. "
 * NB I also notice (after a swift web search) that the word "Adelinidae" only occurs in this dictionary, and is almost certainly a misprint for Aphelinidae.
 * In other words, in adelphoparasites, mated and unmated females exhibit different behaviour, such as in the example given, Encarsia perplexa. Again quoting from the ref, "A mated female lays a single diploid egg in any nymphal stage of the citrus blackfly, but prefers the second stage, and this egg will produce a female [...] Virgin females lay haploid eggs in the fully developed larva of the Encarsia perplexa female (their own species) and thereby produce males (adelpho-parasite). The sex ratio in the field is about 1:7 (male:female)."


 * As regards the other example, Bonellia viridis, this appears to be a case of Environmental sex determination (ESD).
 * "In this species, the vast majority of sexually undifferentiated larvae metamorphose into males when exposed to females, but differentiate into females when developing in the absence of females. [...] In a small fraction of larvae, sex determination is genetic (i.e. the larvae are syngamic); these larvae are predetermined to become either male or female (Jaccarini et al. 1983). In the remaining larvae, sex is determined environmentally (i.e. the larvae are metagamic); the environmental factor that triggers sex determination is the presence or absence of a masculinising stimulus normally due to a substance produced by females. Larvae exposed to females or their secretions thus metamorphose into males, while those that are not metamorphose into females. However, some larvae become intersexes (individuals showing a mosaic of male and female characteristics) and others stay permanently undifferentiated; both these types cannot reproduce and soon die." (pages 1-2 of the pdf)
 * Again, although I am no sort of expert, I would say this has nothing to do with adelphoparasitism at all: both the examples given produce different sexes, but for entirely different reasons.


 * Therefore I would say (as a complete non-expert) that the 'Adelphoparasitism' section is slightly misleading at best because it doesn't explain the difference between mated and unmated females in the wasps, and the worms reproduce through an entirely different non-parasitic mechanism. I suggest you should definitely post a question on the talk page, citing my answer if you like, or even make the changes yourself if you feel confident. Best wishes, MinorProphet (talk) 17:03, 8 May 2021 (UTC)

I don't think I understand the concept enough to make the changes but I'll try doing some more research on the topic. Feralcateater000 (talk) 18:21, 8 May 2021 (UTC)

Is there any "preening" like behavior in animals?
I really like "preening" behavoir concept in birds. Is there any alike behavoir in animals? Rizosome (talk) 17:59, 8 May 2021 (UTC)
 * The very first line of the preening article states "For similar behaviour in other animals, see Personal grooming." A fairly obvious hatnote in that aricle points to Social grooming for the general topic among various animals. Go read it. DMacks (talk) 18:18, 8 May 2021 (UTC)
 * As birds are animals, I am rather confused by your question.--Khajidha (talk) 19:53, 9 May 2021 (UTC)

Scraping fat from animal skin
Why did Neanderthals use their teeth as shown here for scraping off the fat from animal skin, instead of just holding the skin on the ground and doing the scraping on the ground? Count Iblis (talk) 19:31, 8 May 2021 (UTC)
 * [Note: People in the UK won't be able to view this clip, because Warner Bros. International have blocked it on copyright grounds. PaleCloudedWhite (talk) 19:41, 8 May 2021 (UTC)


 * The voice-over commentary states, "The mother first scrapes off fat and sinews with a sharp flint blade . She uses her teeth as a vice " (" vise " for USians) (4:26–4:44). The latter, apparently, to hold the skin taut (stretching it between her mouth and one hand while holding the blade in her other hand), without which the scraping action is ineffective. Holding the skin on the ground would require a surface that is flat, smooth and hard; also, it might damage the skin and the blade more easily. --Lambiam 19:58, 8 May 2021 (UTC)


 * Recent research suggests that early modern humans used this "third hand" too - Like Neanderthals, early modern humans used their teeth as tools. Alansplodge (talk) 00:41, 9 May 2021 (UTC)
 * I don't think we've stopped doing that. Gråbergs Gråa Sång (talk) 09:20, 9 May 2021 (UTC)


 * Thanks Lambiam, Alansplodge, and Gråa Sång for your answers. Count Iblis (talk) 00:44, 11 May 2021 (UTC)

Does Covid immunity cross-protect against MERS?
In this century, we've seen three seriously scary coronavirus-induced diseases; namely SARS (which we should probably now call SARS 1), MERS, and Covid-19 (aka SARS 2). The last time I looked, it seems like SARS 1 has vanished or nearly -- I couldn't find much reference to it after 2017 at the latest. But I gather that MERS is still sort of hanging around with the odd case now and then.

Has there been any study of whether Covid immunity, either natural or vaccine-induced, has any protective value against MERS? Is there any theoretical reason to expect that it does or does not? --Trovatore (talk) 20:48, 8 May 2021 (UTC)
 * Perhaps "SARS 1" should be renamed COVID-02, just like some use the moniker COVID-12 for MERS. According to the article Betacoronavirus, "The receptor usage is not very conserved; for example, among Sarbecovirus, only a sub-lineage containing SARS share the ACE2 receptor." This is formulated somewhat fuzzily; I thought that the subgenus of the sarbecoviruses was the same as the lineage formed by the SARS-CoV strains. If my interpretation of the (unsourced) statement is correct that it means the ACE2 receptor is only found, among the betacoronaviruses, for SARS viruses, then this implies that vaccine-induced COVID immunity (based on this receptor) will not offer protection against MERS. --Lambiam 10:48, 9 May 2021 (UTC)
 * Hmm, "Covid-12" strikes me as an infelicitous name, given that it's more distantly related to Covid (I'm not going to keep putting 19; that's just silly) than the latter is to SARS. I would go with SARS-1, MERS, and SARS-2.
 * Anyway I'm not sure I see the relevance of the receptor. The vaccines target the spike protein, and it seems to me that the real question is to what extent the circulating antibodies bind to (or the killer T-cells detect) the MERS spike protein if they're tuned for the Covid one. --Trovatore (talk) 19:01, 9 May 2021 (UTC)
 * The relevance is that ACE2 receptor is what the spike protein binds to with SARS-CoV-2. If MERS spikes aren't binding to ACE2, that suggests a significantly different structure to their spike protein. If that is the case, it would also suggest that COVID19 vaccines would have limited or no effectiveness at conferring immunity to MERS. --OuroborosCobra (talk) 19:08, 9 May 2021 (UTC)
 * According to this article, MERS spike proteins bind to DPP4 receptors, and not ACE2 receptors. --OuroborosCobra (talk) 19:11, 9 May 2021 (UTC)
 * And for clarity, binding to ACE2 may be of relevance for somewhat related coronaviruses, but it's probably of limited relevance for fairly unrelated ones since it seems unlikely convergence would produce a sufficiently similar spike protein. HCoV-NL63 an alphacoronavirus does use ACE2, but its spike protein and even method of entry is distinct [//www.pnas.org/content/106/47/19970] [//onlinelibrary.wiley.com/doi/10.1002/prot.26024] [//pubmed.ncbi.nlm.nih.gov/16339146/]. Nil Einne (talk) 16:18, 10 May 2021 (UTC)
 * This is unlikely as even the anti-body responses to SARS-CoV-1 and SARS-CoV-2 are not mutually cross-protective. Ruslik_ Zero 19:49, 9 May 2021 (UTC)
 * Though disease induced responses, which are directed against proteins other than spike, can be cross-protective. Ruslik_ Zero 19:51, 9 May 2021 (UTC)

OK, thanks, all. Disappointing. --Trovatore (talk) 19:47, 10 May 2021 (UTC)
 * It's worth remembering that, even just from a taxonomic perspective, MERS and COVID19 causing viruses are as distant as we are from homo habilis. In terms of actual molecular genomics (which taxonomy is still catching up to), they might be even further apart. Saying they are both coronaviruses is roughly the same as saying "humans and orangutans are both great apes." We are, but that's because it's a fairly large umbrella. --OuroborosCobra (talk) 20:11, 10 May 2021 (UTC)


 * Note that while MERS and COVID use different receptors to enter cells, they can still end up entering the same cells and end up mixing with each other, because there are cells that have both receptors. Such cells are particularly prevalent in the small intestines as pointed out in this article. MERS is endemic in dromedary camels, e.g. in Kenya almost 50% are carriers. And now with COVID spreading there, so it's not an unlikely scenario for COVID to infect camels there. If COVID also gets endemic in dromedary camels then the two viruses will end up mixing quite frequently with each other, and it's then possible for a new, far more deadly pandemic to arise out of dromedary camels. Count Iblis (talk) 00:54, 11 May 2021 (UTC)