Wikipedia:Reference desk/Archives/Science/2017 February 17

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February 17

Plant from Bangladesh

Which plant is farmed here? I've never seen such fruits.--Sascha GPD (talk) 13:45, 17 February 2017 (UTC)

Hard to tell. The fruit resembles durian or maybe jackfruit or maybe breadfruit. --Jayron32 14:22, 17 February 2017 (UTC)

Amongst other things, the leaves look wrong for all 3 of these to me. Nil Einne (talk) 15:01, 17 February 2017 (UTC)

Doing more google searches, other spiky green fruits include guyabano, or some species of cucumber, such as a luffa or Marah (plant) (aka manroot). --Jayron32 16:37, 17 February 2017 (UTC)

I'll admit the first thing I did was take a quick look at the breadfruit article... then I realized this would be hard. I suck at botany, but my notion is that the first thing you do is fire up the glossary of leaf morphology and open the image to full resolution. At center-right far-top there's a little clearing and you can see the leaf beneath it, and various others, have branching leaf veins and jagged edges, with the veins apparently running to the narrowest parts of the edges. So I would say these are simple leaves (our redirect just takes you to leaf). The margin I would call "dentate" rather than "serrated" because the "teeth" seem symmetrical, and not "crenate" because they seem roughly zigzag. I think the shape of the leaf is "heart-shaped" = "cordate" - not to be confused with a chordate! In places the vein branching matches our figure for "dichomatous", in others "palmate" - I'll let someone else take a bite at that apple. And while the perspective confuses me a bit, I think I can see there are long stems supported on a framework that have leaves branching "alternately" in each direction, toward and away from us. So I am going to suggest that additional searches include dentate cordate alternate ... and I'll hope for a miracle. ;) Wnt (talk) 19:35, 17 February 2017 (UTC)

I should mention I did have a look at various other Artocarpus, none of them seem to have similar leaves. So perhaps either a speciesly less commonly cultivated or somethign else. Nil Einne (talk) 03:24, 18 February 2017 (UTC)

My guess is some member of the family Cucurbitaceae, superficially it resembles Echinocystis lobata but it seems that species is not cultivated. Most likely it is of the genus Cucumis (same as cucumbers) Cucumis zeyheri has similar morphology but appears to grow on the ground rather than as a climbing vine. Hope this helps. 204.28.125.102 (talk) 00:31, 18 February 2017 (UTC)

Is abstract thinking unique to Homo sapiens?

--IEditEncyclopedia (talk) 14:19, 17 February 2017 (UTC)

Wikipedia has an article on Animal cognition which would be a good starting point for your research. --Jayron32 14:24, 17 February 2017 (UTC)

Is there non-circle Neanderthal geometric art? Like squares or triangles? If there isn't then maybe yes. Or maybe not. Even were that 100% foolproof maybe there were millions of Neanderthals in all time and only one had abstract thought and we've just never found his drawings of cubes and icosahedrons. Sagittarian Milky Way (talk) 14:31, 17 February 2017 (UTC)

And what do you call a 1/8th homo sapiens who had the smarty genes from her homo sapiens great-grandparent and the ability to bench press hundreds of pounds from her 7 Neanderthal great-grandparents? Sagittarian Milky Way (talk) 14:45, 17 February 2017 (UTC)

Apparently John Urschel ;-). --Stephan Schulz (talk) 15:56, 17 February 2017 (UTC)

It would be difficult to test for animals fully understanding abstract thought, so we might do better to test for their understanding of things like scale models first. For example, show them a scale model of a room with a treat hanging out of a box, then take them to the full-sized room and see if they check out the full-sized box first (don't actually put a treat in it or they might smell it). If they don't understand scale models, there doesn't seem to be much hope for them understanding more complex abstract concepts. StuRat (talk) 16:33, 17 February 2017 (UTC)

Yes, it is difficult, but a cursory search shows that a number of scientists have designed a range of test for assessing abstraction on non-humans, and then published the results in peer-reviewed studies. Science is often difficult, but that is no reason things can't be studied and understood. I wonder- how long did you look for references on this? SemanticMantis (talk) 18:33, 17 February 2017 (UTC)

If you can find animals that can handle scale models, then the next step is to make it a scale model, except that it's a mirror image, and see if they can handle that, then start changing details, like make it a different type of chair and box in the room. Then perhaps try a photo of the room, then a map. At this point, we are getting into fully abstract thought, or we can identify precisely where each animal falls short. StuRat (talk) 22:23, 17 February 2017 (UTC)

This being the science desk, I don't think abstract thought has a definition sufficiently precise to qualify for use in the question posed, which is Is abstract thinking unique to Homo sapiens? Bus stop (talk) 17:06, 17 February 2017 (UTC)

There are certain terms which have more precise meaning in psychology and philosophy which may be more precise, such as metacognition and theory of mind. We even have an article titled Theory of mind in animals and Animal consciousness, although both of those suffer from the same issues as human definitions as noted in hard problem of consciousness. --Jayron32 18:24, 17 February 2017 (UTC)

• No. Not according to some definitions and some research. See e.g. Visual categorization: accessing abstraction in non-human primates [1] and A non-human primate test of abstraction and set shifting: An automated adaptation of the Wisconsin Card Sorting Test [2]. Both articles are freely accessible, you can look at the prior work they cite, and you can use google scholar to look at other articles that cite these works. SemanticMantis (talk) 18:32, 17 February 2017 (UTC)

First of all, I'm not entirely sure that I use the term "abstract thought" in the same way that others do here, so forgive me if I go off on a tangent. There were some famous observations by Wolfgang Kohler which may be relevant here. Kohler had a large enclosure containing several chimps. There was a bunch of bannanas hanging very high in the enclosure, and on the ground there were various items, including several crates and sticks. The story goes that one day, a chimp piled 3 crates on top of each other (without trying to get the bannanas between stacking crates). After the third crate had been stacked, the chimp grabbed a stick,climbed the crates, and reached up with the stick to get the fruit. One account of this is here[3]. There are a couple of other terms used in this area of ethology which might be helpful for research. These include "gestalt" or "gestalt thinking", or the Eureka moment. DrChrissy ^(talk) 18:58, 17 February 2017 (UTC)

• I wouldn't call that abstract thought, it's tool use. Visualizing how to stack the boxes is not abstract, but rather a concrete thought process. Similarly, crows use tools [4], and any bird building a nest or perhaps spider building a web is using similar concrete thought processes. StuRat (talk) 19:08, 17 February 2017 (UTC)

Oh yes, it could be classified as tool use - it could be placed in several other categories of behaviour - perhaps cognitive trial-and-error. What do you mean by a "concrete thought process" - this is not an ethological term I have encountered before. DrChrissy ^(talk) 19:20, 17 February 2017 (UTC)

side conversation, no references, open at your own time-wasting peril SemanticMantis (talk) 23:40, 17 February 2017 (UTC)

Perhaps tangible is a better word for it then. I mean thought processes which can be visualized physically, like the stacking of blocks, as opposed to an abstract concept like "honor", which can't be. StuRat (talk) 22:20, 17 February 2017 (UTC) But this is now becoming circular. You are using words which can not be defined for non-human animals, such as "honour". If we can't define it, or at least develop a working definition, we can't test it. DrChrissy (talk) 22:34, 17 February 2017 (UTC) This is part of the problem. It's difficult to even define what abstract thought in animals would be, much less test for it. But it's not being able to visualize how to stack blocks. From what we know about humans with no language skills (who later developed them so they could describe what it was like before, like Helen Keller), they thought in terms of pictures, making abstract thought an impossibility. If animals also think this way, then they would have similar limitations. Of course, animals do have some language skills, but they seem to be rather rudimentary. StuRat (talk) 22:57, 17 February 2017 (UTC) I'm sorry but this is going off on tangents which have nothing to do with the OP. You are throwing in terms such as "tangible", "concrete", "visualise" with no definition and in ways that simply do not relate to my understanding of ethology. This is really not helping the reader. DrChrissy (talk) 23:12, 17 February 2017 (UTC) @StuRat:. Why don't you try reading a bit about the topic? I have given two very relevant references, each of which contains working definitions of abstraction, and each of which cites many additional scholarly works. The ones I posted are freely accessible, but some of the works they cite are not. If you would like to read some of them and do not have access, just let me know, and I will be happy to provide copies if I can. This is not a desk for you to approach a field from an ignorant position, and hope to work things out from first principles. This is a reference desk, where our goal is to serve our patrons with references. Since you clearly don't know much about this topic, and cannot (or will not?) supply any suitable references, try reading some of the references provided - try to learn from the experts, rather than stumbling around the topic like a chihuahua in a sock. SemanticMantis (talk) 23:39, 17 February 2017 (UTC) I think that referencing a "chihuahua in a sock" is borderline WP:NPA. It's uncalled for. A questioning of the term abstract thinking is appropriate to the question asked in this thread. Even the distinction between abstract thinking in humans and non-abstract thinking in humans is a worthwhile discussion and, in my opinion, not entirely irrelevant to the the question posed in this thread. Bus stop (talk) 04:18, 18 February 2017 (UTC)

Hopefully this def of abstract thought, which contrasts it with concrete thought, will help you understand the difference better and will help us define, and hence answer, the OP's Q: [5]. StuRat (talk) 23:39, 17 February 2017 (UTC)

This being the science desk, I don't think abstract thought has a definition sufficiently precise to qualify for use in the question posed, which is Is abstract thinking unique to Homo sapiens? Bus stop (talk) 17:06, 17 February 2017 (UTC)

By abstract thought, I mean the ability to hypothesize. To create ideas about different things such as God, moon, sun, rainfall, thunderstorm etc. Humans created abstractions about these things, which are gradually evolved with new knowledge. At first, humans thought sun and moon to be planets revolving around Earth. Do other animals have this ability to create ideas about things? --IEditEncyclopedia (talk) 07:58, 18 February 2017 (UTC)

According to Gorilla#Intelligence, "Some researchers believe gorillas have spiritual feelings or religious sentiments". Does religious feelings count as abstract thought? --IEditEncyclopedia (talk) 08:25, 18 February 2017 (UTC)

Elephants are known to visit the bones of their dead relatives, and this can be taken as them assigning some deeper meaning to those bones, but not definitely. StuRat (talk) 16:42, 19 February 2017 (UTC)

I , for one, am getting completely lost in the moving goal-posts of this almost totally anthropocentric thread. How can we possibly discuss whether non-human animals "think" about God when so many humans would deny his/her existence? Then on the other hand, do animals have abstract thoughts about rain. I don't know whether they have abstract thoughts about rain, but I know that many, many animals react to rain and many animals appear to be able to predict rain. Going back to anthropocentrism and God. Here comes my bit of OR. I have two cats. They have a collection of toys which I tend to keep all lumped together. One of my cats regularly, without any prompting, goes to this pile of toys and brings back the same toy each time for me to throw for him. Anthropocentrism means we are essentially locked in our human skin. How can I possibly know what my cat is thinking when he walks to the toy pile to get his favourite toy. Perhaps he believes it is a God in the same way that some humans have an abstract thought about God? DrChrissy ^(talk) 10:59, 18 February 2017 (UTC)

Perhaps some animals will weigh in on this question... Bus stop (talk) 14:48, 18 February 2017 (UTC)

Several already have - we refer to them as editors. DrChrissy ^(talk) 15:42, 18 February 2017 (UTC)

So, the question restated is "Is abstract thinking possible in humans?" Bus stop (talk) 16:15, 18 February 2017 (UTC)

Well not really, you are asking a completely different question. DrChrissy ^(talk) 16:25, 18 February 2017 (UTC)

A related question is whether animals and birds are required to obey the Ten commandments, and whether they are aware that they sin by disobeying. I regularly watch birds eating thrown-out bread, and it's not at all unusual to see one of them stealing a piece that another bird is eating, when there are plenty of unclaimed pieces on the ground. It's obvious that not all humans obey the commandments at all times, indicating free will to sin or not sin and guilt if they do. If the commandments are universal, we could conclude that animals also experience guilt when they disobey one. Akld guy (talk) 19:50, 18 February 2017 (UTC)

The survival instinct often overrides everything else, in both humans and non-humans. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:53, 18 February 2017 (UTC)

@ Akid guy. I can not agree. Even if the 10 commandments were universal, this in no way means we can conclude non-human animals experience guilt if they violate one of these. I feel guilt if I find a £10 note in a shop and decide to keep it for myself rather than find the owner. There are many persons in our prisons who feel no guilt at having committed serious crimes against others. Even within our own species we would be pushed to conclude that the feeling of guilt due to violation of the 10 commandments causes guilt throughout our species. DrChrissy ^(talk) 21:22, 18 February 2017 (UTC)

My username is AKLD guy. Akld is one of the abbreviations in NZ for Auckland. Akld guy (talk) 23:41, 18 February 2017 (UTC)

Apologies for mis-reading your username. DrChrissy ^(talk) 00:03, 19 February 2017 (UTC)

Now, if your name was aphid guy you could weigh in authoritatively on this question pertaining to animal intelligence... Bus stop (talk) 00:58, 19 February 2017 (UTC)

Don't know about survival instinct overriding all else, humans do seem to have exceptions in this regard. Suicide is an everyday concept in most human societies (some even deem it honourable in certain circumstances, others see it as a disgrace, and yet others see it to be sympathized with, but discouraged, and even forcibly prevented), but would you ever see an animal intentionally do it, on the lines of human suicide? Do they have the thought processes to allow for the kinds of suicide logic seen in humans? Eliyohub (talk) 18:19, 19 February 2017 (UTC)

We actually have an article Suicide in animals but in my opinion it is so poor I can rarely bring myself to edit it. DrChrissy ^(talk) 18:25, 19 February 2017 (UTC)

Spider and snake

About this video: http://videos.elmundo.es/v/0_ynih8y9m-esta-arana-acaba-con-una-serpiente-10-veces-mas-grande?uetv_pl=virales&count=1 What kind of spider is this and what is she planning to do with the snake, eat it somehow?? Thanks, --ZygonLieutenant (talk) 16:39, 17 February 2017 (UTC)

I tried three times on two different browsers, and got a "connection error" on the video every time. If you can find another copy of the video hosted elsewhere, or can tell us where it originally appeared, that might help.

However, there's a decent chance you saw this video [6] of an Australian redback spider attacking a snake, though the version I link ends before the snake is clearly dead. The video clip is understandably very popular, and has been shooting all around the internet the past few days, so I think that might be what you saw. SemanticMantis (talk) 19:36, 17 February 2017 (UTC)

_{Ummm yes it's the same video and it's faked. Blooteuth (talk) 19:03, 17 February 2017 (UTC)}

Is that your opinion, or do you have some reference to support the claim? Are you claiming it's not a spider? Or not a redback spider Or not a snake? Or that it is a spider and a snake but the spider is not at Can you explain what you mean by that, and give references if possible? Also, you have interjected you comment in the middle of my post, in violation of WP:THREAD. Please follow our guidelines, they help us keep things intelligible and organized here. Rather than move all the related comments around, I will simply sign again above, but please don't make extra work for us. SemanticMantis (talk) 19:08, 17 February 2017 (UTC)

I was just about to reply supporting Blooteuth. My opinion, and it is only opinion, is that the video is likely to be faked. I lived in Australia for 12 years and have plenty of experience of red-backs. The one in the video looks absolutely ENORMOUS. Our Redback spider states "Females have a body length of about 10 millimetres (0.4 in), while the male is much smaller, being only 3–4 mm (0.12–0.16 in) long." The beast in the video looks very much larger than this. DrChrissy ^(talk) 19:15, 17 February 2017 (UTC)

I have no strong opinion on this specific video, but have no problem believing such a thing could happen, given the descriptions in the ref I just posted below. I agree the spider looks a bit bigger than 10mm, but the angles are odd, and there is considerable variance in female size [7] SemanticMantis (talk) 19:18, 17 February 2017 (UTC)

Oh, I agree this behaviour could happen, I'm just not sure about this particular video. It's a shame there were not more objects in the background to help judge size and perspective. Or better still, a person in a white lab coat placing a ruler by the side of the spider, perhaps with a running commentary about how many of her mates she had eaten in the last month! ;-) DrChrissy ^(talk) 19:52, 17 February 2017 (UTC)

As for the second question: some spiders can and do eat snakes sometimes. The spider venom of some species can act to essentially liquify the interior of prey, letting the spider suck out all it wants (some additional info here [8]). See here [9] for a similar example. SemanticMantis (talk) 18:18, 17 February 2017 (UTC)

re the Daily Mail story: I'm not sure I have heard of red-backs throwing their web at potential prey. I know some spiders hunt a little like this (see bolas spider) but I always thought the red-back was a sit-and-wait character. DrChrissy ^(talk) 19:07, 17 February 2017 (UTC)

Yeah, I wouldn't vouch for anything the DM says with respect to biology. However, this review article [10] says, with additional reference "Latrodectus hasselti spiders enjoy a varied diet, trapping some 60-70% of beetles as well as other kinds of insects, spiders, small mice and occasionally lizards which blunder into their sticky trap lines." It continues to describe how the spider incapacitates prey by "squirting a swathe of viscous silk over its target." The article does not specifically describe snakes being caught in this manner, but to me, it's not hard to believe that a spider that can catch lizards can also catch a small or even (perhaps rarely) medium-sized snake. SemanticMantis (talk) 19:17, 17 February 2017 (UTC)

Great reference - thanks very much. DrChrissy ^(talk) 19:25, 17 February 2017 (UTC)

The video got an article on National Geographic's website. [11] 209.149.113.5 (talk) 19:50, 17 February 2017 (UTC)

Thanks! They don't seem very skeptical... SemanticMantis (talk) 20:17, 17 February 2017 (UTC)

Looks like there's a fishhook holding the snake in place. Justin15w (talk) 20:12, 17 February 2017 (UTC)