Wikipedia:Reference desk/Archives/Science/2023 March 14

= March 14 =

Antibody-dependent_enhancement in COVID-19
Hello everyone, I'm working on a review for COVID-19. I'd like kindly ask that is there any research supporting Antibody-dependent_enhancement in COVID-19? -Lemonaka‎ 00:50, 14 March 2023 (UTC)
 * If you find any in highly-WP:MEDRS sources, please update COVID-19_vaccine_misinformation_and_hesitancy. DMacks (talk) 07:57, 14 March 2023 (UTC)
 * If anybody is actively searching for this, in this process it is the virus that binds to the antibodies, so "SARS-CoV-2" (in conjunction with a search term like "antibody-dependent enhancement" or "antibody-dependent infection") may be a better search term than "COVID-19". As the phenomenon has been observed for SARS-CoV (see ), it is a likely possibility for the closely related SARS-CoV-2. --Lambiam 09:44, 14 March 2023 (UTC)
 * Look here for a meta-analysis dated 19 September 2022. TL;DR: "However, further research is needed to confirm the conclusion that ADE does not occur with SARS-CoV-2 infection." --Lambiam 09:47, 14 March 2023 (UTC)
 * @Lambiam Thank you, I will read this essay ASAP. -Lemonaka‎  11:10, 14 March 2023 (UTC)

Health effects of chocolate#Cadmium content

 * https://en.wikipedia.org/w/index.php?title=Health_effects_of_chocolate&diff=prev&oldid=1144606683&diffmode=source
 * User:Zefr Special:Contributions/Zefr says : No WP:MEDRS or regulatory sources
 * but: U.S. Food and Drug Administration
 * Under 1986 California Proposition 65 these products are reportedly labeled in stores
 * and cadmium accumulation in Theobroma cacao
 * ??? .... 0mtwb9gd5wx (talk) 22:15, 14 March 2023 (UTC)


 * And the question for the reference desk is...
 * This seems like a discussion for the article's talk page (with a request to participate on the reverting editor's talk page). Or maybe try the WP: Help desk? 136.56.52.157 (talk) 22:58, 14 March 2023 (UTC)

Human lineage from LUCA
Is there anywhere a species-by-species reconstruction of human lineage from, say, LUCA up to Homo sapiens? The farthest I've seen started on or around primates. Thanks. 212.180.235.46 (talk) 23:48, 14 March 2023 (UTC)
 * Given that there isn't even a species-by-species reconstruction from LUCA to the first archaea, let alone to the first eukaryotes, I'd say no. --OuroborosCobra (talk) 23:55, 14 March 2023 (UTC)
 * The book The Ancestor's Tale by Richard Dawkins and Yan Wong presents a good outline of this, although it works from the present backwards. Our article has quite a detailed summary.
 * The 'backwards' approach could be a little confusing if one is not already familiar with the broad facts, but it has the advantage of not falsely suggesting some sort of 'destiny' or 'goal' to which evolution was aiming. {The poster formerly known as 87.81.230.195} 5.64.160.67 (talk) 07:25, 15 March 2023 (UTC)
 * The vast majority of an estimated 5,000,000,000 species that have ever existed are completely unknown, having left no trace of ever having existed as a species. Whichever technique is chosen, this also holds for the vast majority of species on the chain from LUCA to any present-day species. --Lambiam 08:37, 15 March 2023 (UTC)
 * Interesting, skimming through the article shows all animals, but shouldn't this 5 billion number include bacteria and plants, that went extinct? 2601:249:8200:A640:F4A8:1C8A:2A78:8203 (talk) 16:47, 15 March 2023 (UTC).
 * Absolutely, and expanding that article to cover extinct organisms outside the animal kingdom sounds like a terrific project for an ambitious editor to begin. I have a feeling that it's been left out somewhat due to the "community" nature of Wikipedia. Many of us grow up with a big interest in prehistoric animals, be that dinosaurs or animals from the Cambrian explosion, etc., but how many of us grew up learning about extinct bennettitales seed plants like Ptilophyllum? Probably not nearly as many. There aren't a ton of movies or kids shows made about Gangamopteris. A shame, really. I only recently learned about Prototaxites from as early as the Silurian, a fungi that grew to heights of 8 meters and formed the first terrestrial "forests" before vascular plants took that mantle, from the Paleo Analysis Youtube channel. --OuroborosCobra (talk) 18:34, 15 March 2023 (UTC)
 * LUCA is still alive, though. Abductive  (reasoning) 08:03, 16 March 2023 (UTC)
 * Um, what? LUCA likely lived about 4 billion years ago. It's the last universal common ancestor. Even if the same species is still alive today (and that's a big if, given that it's descendants became far more specialized and better adapted to ever changing niches and biomes), they still wouldn't actually be LUCA, just like I am neither Lucy (despite being descended from her species) or Scarlett Johansson (despite being from the same species), and I am not my own grandfather, despite being the same species and descended from my grandfather. ANy living members of the species of LUCA would just be descended from LUCA, just like everything else today. --OuroborosCobra (talk) 13:10, 16 March 2023 (UTC)
 * Every bacteria, archaeon and protist that has been reproducing asexually since LUCA arose is LUCA. She's just been dividing. Moreover, we define LUCA as the sort of average, or median, or consensus of all the life alive today. Which makes her still alive. Abductive  (reasoning) 18:36, 16 March 2023 (UTC)
 * Please don't confuse people by using your own incorrect definition of a well-defined term. Fgf10 (talk) 11:52, 17 March 2023 (UTC)
 * If you think LUCA is well-defined, you've got another think coming. Abductive  (reasoning) 19:05, 17 March 2023 (UTC)
 * The definitions we give are a bit of a mixed bag. In the LUCA article, we define her as "the most recent population from which all organisms now living on Earth share common descent—the most recent common ancestor of all current life on Earth". So she is a population, but, moreover, you and I have to descend from it. I don't think bacteria figure in my chain of descent. But the definition also has a second part: LUCA is an MRCA, which is defined as "the most recent individual from which all the organisms of the set [in this case, all organisms now living on Earth] are descended". When LUCA saw the light of day (figuratively speaking – it may have been pitch dark down there and she may not have had sensory organs), reproduction was almost certainly asexual, so the population was then possible a set containing a single individual. --Lambiam 12:14, 17 March 2023 (UTC)
 * Two questions from a novice: (1) why "she"? If this is before sex then surely "it"?  (2) How can the "Last universal common ancestor" have been prey to viruses if it/she was a common ancestor to all living things? Martin of Sheffield (talk) 12:25, 17 March 2023 (UTC)
 * She because it's funny and sort of true, and viruses aren't alive. LUCA is the last common ancestor, but was preceded by a whole lot of entities in the primordial soup. Possibly some of these entities could be infected by viruses and other replicons. Abductive  (reasoning) 19:05, 17 March 2023 (UTC)
 * Ah well, humour is in the mind of the beholder, I just don't see it. Virus implies that they on the edge of life, it depends on how you want to define life Koonin & Starokadomskyy seems to sum up the dichotomy fairly well.  Oops, forgot the signature, sorry all. Martin of Sheffield (talk) 22:54, 17 March 2023 (UTC)
 * Viruses do what they do, and they couldn't care less whether we define them as "alive" or not. As to the "she" part, maybe it would be "he" if it were LUKE instead of LUCA. ←Baseball Bugs What's up, Doc? carrots→ 04:58, 18 March 2023 (UTC)
 * Electric toothbrushes do what they do and do not care either whether we define them as "alive" or not. This observation is not a helpful argument in a discussion whether electric toothbrushes should or should not be covered by a definition of "life". --Lambiam 08:42, 18 March 2023 (UTC)
 * Do you consider our planet to be alive? ←Baseball Bugs What's up, Doc? carrots→ 10:27, 18 March 2023 (UTC)
 * Is my personal opinion relevant to the discussion? If so, how so? If not, why do you ask? --Lambiam 16:16, 18 March 2023 (UTC)