Wikipedia:Reference desk/Archives/Science/2009 April 2

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April 2

Hominidae?

In layman's terms, how can one easily distinguish Hominidae (humans, bonobos, chimps, gorillas and orangutans) as different from other primates (or other mammals in general)? Do they have certain easy characteristics that set them apart from other primates? Maybe their weight?--Sonjaaa (talk) 00:20, 2 April 2009 (UTC)

According to the article, distinguishing characteristics include the absence of a tail, and sexual dimorphism (males larger than females in this case). ~AH1^(TCU) 00:44, 2 April 2009 (UTC)

And, of course, they are more intelligent. For example, there's the test of leaving a series of boxes on the floor and a banana hanging from the ceiling, where the more intelligent primates can figure out how to stack the boxes to get to the food, while less intelligent primates can't. StuRat (talk) 11:54, 2 April 2009 (UTC)

Oh - THAT'S how you do it? I always wondered. SteveBaker (talk) 13:22, 2 April 2009 (UTC)

How about developing IQ tests for bonobos, chimps, and gorillas to see which is the more intelligent species? That would also show much variation there is in intelligence among individuals of the same species. Maybe IQ tests could be developed for other animals too. The thought that would go into developing animal IQ tests might show how to improve the validity of human IQ tests too. The same test could not be used for all animals because their intelligence varies so much. Separate tests would have to be developed for use with closely related species only. The basic thinking patterns of various species would also require different tests - for instance, separate IQ tests would be needed for cats and dogs. Obviously, animal IQ tests could not be written tests, but would be administered on a food reward basis. - GlowWorm. —Preceding unsigned comment added by 98.17.35.74 (talk) 13:56, 2 April 2009 (UTC)

There are skeptics that IQ is a good test for intelligence for humans. I think it would be even less effective for animals. 65.121.141.34 (talk) 15:35, 2 April 2009 (UTC)

With human IQ tests there is the well-known problem of a person's former experience aiding him in doing the test. If he reads well, he will do better on an IQ test. If he has taken a lot of such tests, he knows how to go about it. He may even have seen similar questions before, such as rope-and-pulley problems. He may also be familiar with the way the questions are asked. (In poll taking, the way a question is asked can influence the answer.) In contrast, wild animals of the same species that have been taken very recently from the same environment, will mostly have about the same former learning experiences – not in IQ tests but in life experiences. There will be more variations in life experience with farm animals, pets, and possibly in wild animals that have lived near humans. – GlowWorm. —Preceding unsigned comment added by 98.17.35.74 (talk) 15:53, 2 April 2009 (UTC)

One type of IQ test that works on a variety of animals is the mirror test:

1) The least intelligent animals act as they would when they encounter another animal of their same species and gender. In the case of male crabs, for example, they will attempt to fight with their mirror image.

2) More intelligent animals, like cats and dogs, might react as above briefly, but, after looking behind the mirror and sniffing it, realize it's just some type of illusion and move on.

3) The most intelligent animals (such as those mentioned in this Q) eventually realize that they are seeing their own image, and are fascinated by it. For example, they may use it to try to look at parts of their body they can't normally see. StuRat (talk) 17:12, 3 April 2009 (UTC)

That's very interesting. Do you know how some of the smarter birds, such as ravens or crows, react? -GTBacchus^(talk) 17:18, 3 April 2009 (UTC)

Actually, Google answered my question very quickly. Magpies get it. -GTBacchus^(talk) 17:21, 3 April 2009 (UTC)

Birds seem to have an extreme variation in intelligence, between chickens at the stupid end and parrots (and apparently magpies) at the smart end. StuRat (talk) 15:07, 8 April 2009 (UTC)

They look like people, unlike other animals such as dogs, cats, horses, snakes, rats, birds, etc. Edison (talk) 04:52, 3 April 2009 (UTC)

5 in one fruit tree

I've seen these five-in-one grafted fruit trees in catalogs, but what I'd like to know is, are there any drawbacks to grafting five different types of plant (sometimes of different, but related species) to the same tree? Different species have different needs, so I would think that having five different types of tissue in one tree would compromise the integrity of the whole tree in some way. It's a really neat idea (the tree I'm looking at possibly buying has five different species of fruit from the genus prunus on it), but it could be just a gimmick to sell trees that aren't that good. Please help me decide whether I should buy a combination tree or simply buy one that has only one species and cultivar. Thanks, Wikipedians! 63.245.144.68 (talk) 00:58, 2 April 2009 (UTC)

I think your example shows that this only works if the plants are all similar, which would mean they have similar nutritional requirements. Grafting has been used commercially, which seems to indicate that it has some benefit. I imagine the grafted tree is more expensive, and you could have the problem of a "graft failure", which can't happen in a normal tree, in addition to the regular things that can go wrong with a tree. So, I'd say that you should get the grafted tree if you really want all those varieties, and stick with a normal tree otherwise. StuRat (talk) 11:48, 2 April 2009 (UTC)

For some plants grafting is the only way to be sure about the quality of the fruits you will eventually get out of the tree. I believe Prunes, Apricots, Peaches and Nectarines are so closely related that it is unlikely that the multiple grafting should be a problem. Dauto (talk) 14:00, 2 April 2009 (UTC)

shouldn't that be plums? Prunes are dried plums.--TammyMoet (talk) 17:56, 2 April 2009 (UTC)

Maybe he forgot to water the tree... - Eron^Talk 18:02, 2 April 2009 (UTC)

Yes, I meant plums. I got misdirected by the word prunus for the genus. Dauto (talk) 05:14, 3 April 2009 (UTC)

We actually had a prune tree once. It had something wrong with the skin on the plums, so it wasn't waterproof. This caused them to shrivel into prunes while still on the branch. We should have thought to market the tree (perhaps in Florida ?), maybe we'd be rich by now. StuRat (talk) 16:52, 3 April 2009 (UTC)

Dauto is right that only closely related types of fruit can be successfully grafted. Grafting different types varieties of fruit on the same tree is really only done as a novelty, not for serious fruit production. What happens is that one type tends to take over the entire plant, since it is very difficult to have exactly equal vigor for each variety. So, buy one if you want to create a conversation piece and amaze your neighbors, but buy separate trees if you want the fruit for eating.--Eriastrum (talk) 17:24, 2 April 2009 (UTC)

"Dauto is right that only closely related types of fruit can be successfully grafted." Actually, I said that. StuRat (talk) 16:44, 3 April 2009 (UTC)

Sorry, Stu, I didn't read your post carefully. Won't happen again.--Eriastrum (talk) 20:57, 4 April 2009 (UTC)

No prob. Sometimes I say things I wish I could blame on someone else. :-) StuRat (talk) 16:52, 5 April 2009 (UTC)

When I was a child we had one of these. The first summer it produced five kinds of apples. Then after a hard freeze during the winter, the grafts died and it only produced one kind of apple. Edison (talk) 04:50, 3 April 2009 (UTC)

HAMMER DRILL VS IMPACT DRILL

WHAT IS THE DIFFERENCE? —Preceding unsigned comment added by 64.88.177.194 (talk) 01:11, 2 April 2009 (UTC)

Please do not type in all caps. It makes it appear that you are screaming, and is pretty rude. Now, to answer your question... Nothing. They are the same item. If you look for an article on impact drill you will see it redirects to our article on hammer drill. There may be some marketing differences, for example one manufacturer may use one term and a different one may use the other, but functionally they are the same tool. --Jayron32.talk.contribs 01:20, 2 April 2009 (UTC)

Maybe you mean Impact driver or Impact wrench? In which case a hammer drill uses a hammering action to help break-up the masonry when drilling, where as the other tools I mention use impact to generate large amounts of torque for loosening tight bolts etc.90.220.130.74 (talk) 21:02, 2 April 2009 (UTC)

Life Without Plastics Video

I once saw a humorous brief video detailing "life without plastics" (or oil or petroleum products, etc.) with a 1950s housewife. She is standing in the kitchen and things begin to fall apart. I can't seem to find this anywhere online; where can I find it? —Preceding unsigned comment added by Dlempa (talk • contribs) 03:06, 2 April 2009 (UTC)

Wasn't that on an episode of The Simpsons ? There has been an even more ridiculous one on TV in the USA during the last year or so about "Chemicals" disappearing - which is bizarre since essentially every material object is made of chemicals...but that had a modern theme, not 1950's. SteveBaker (talk) 13:16, 2 April 2009 (UTC)

I believe you're talking about this segment from Kentucky Fried Movie. --Sean 13:48, 2 April 2009 (UTC)

...which was probably inspired by A Case of Spring Fever (presented here as the MST3K version for your convenience and pleasure), or some other educational short film in the same vein. -- Captain Disdain (talk) 20:15, 2 April 2009 (UTC)

Oh god I laughed so hard at that MST3K episode. Springy! --BiT (talk) 20:37, 2 April 2009 (UTC)

The Kentucky Fried movie was the one I was looking for - it was zinc oxide, not plastics. Thanks! dlempa (talk) 20:14, 5 April 2009 (UTC)

Meanings

What is the meaning of A in this picture? In the summary, the abbreviation"ca." means what?96.53.149.117 (talk) 04:33, 2 April 2009 (UTC)

"A" almost certainly means Angstrom units. "Ca." means "circa", or "about". Looie496 (talk) 04:36, 2 April 2009 (UTC)

It very well mean "canada" or located in canada. THIS will be edited out soon so please read quickly.67.193.179.241 (talk) 14:17, 4 April 2009 (UTC)

It can't very well mean that, as we've been given context in which it means "circa". 86.166.149.141 (talk) 00:34, 5 April 2009 (UTC)

Diamond Cutting

What is the reason that Diamonds are used in machine tools, especially when machining non-ferrous alloys, compared to other alloys?96.53.149.117 (talk) 04:45, 2 April 2009 (UTC)

I suspect the author of that line was thinking of non-ferrous alloys that are harder than steel. It seems sensible that one would use diamond on hard materials. You don't use it on materials that can be machined more easily, because it is more expensive than alternative materials.--Srleffler (talk) 05:26, 2 April 2009 (UTC)

from article diamond... "Diamond is not suitable for machining ferrous alloys at high speeds as carbon is soluble in iron at the high temperatures created by high-speed machining, leading to greatly increased wear on diamond tools when compared to alternatives.--Digrpat (talk) 13:06, 2 April 2009 (UTC)

"

When a Star Evolves into a Black Hole...

I was reading List_of_common_misconceptions the other day, and it said:

"Black holes, unlike the common image, do not act as cosmic vacuum cleaners any more than do other stars. When a star evolves into a black hole, the gravitational attraction at a given distance from the body is no greater than it was for the star. That is to say, were the Sun to be replaced by a black hole of the same mass, the Earth would continue in the same orbit. Due to a black hole's formation being explosive in nature, the object would lose a certain amount of its energy in the process, which—according to the mass–energy equivalence—means that a black-hole would be of lower mass than the parent object, and actually have a weaker gravitational pull."

Note that paragraph was removed by an editor earlier today for being poorly sourced so if you look at it now, it's not in there but I still want to ask a question about it.

Assuming that this is correct, if a black hole's gravitational pull is the same as the star that preceded it, how did light escape the star in the first place? Is it because as the star collapsed, its size shrank and the black hole has a higher density? A Quest For Knowledge (talk) 17:54, 2 April 2009 (UTC)

No, as the Schwartzschild radius of such a BH is about 15km, the star's light was sent well outside that. Of course, the gravity decreases alot when going from 15km radius to 100.000km or what a typical star has radius. When you read the scenarios of a BH emitting light, it's always from inside its event horizon. --Ayacop (talk) 18:14, 2 April 2009 (UTC)

Er... I'm not quite sure what to make of the above answer. Generally, your initial understanding is correct. At the surface of the Sun (more relevantly, a point one solar radius from the center of the Sun, 6e5 km away), escape velocity is 6e5 m/s, far less than the speed of light (3e8 m/s). As such, light escapes. If you swapped the Sun for a solar-mass black hole, then escape velocity from a point one (original) solar radius away remains the same, and a light source there is still detectable.

Next consideration: a solar-mass black hole has an event-horizon radius of 15km (I'm going off the above response, and have no idea whether or not it's correct, but it's useful for these purposes). Light can't escape from points at or within 15 km of the center of mass. Here's the key distinction from when it was a star: the Sun's mass is not contained within a 15 km radius sphere, so the Sun's gravity at that point is far less. Volume increases with the cube of radius: if we assumed the Sun to be of uniform density (it's not, but not the point), then we would expect about one trillionth of one percent of the Sun's mass to be within the event horizon of a solar-mass black hole. The mass of the Sun above that radius is evenly distributed, and as such, can be ignored for gravitational purposes. One trillionth of one percent of the mass needed for the black hole obviously doesn't stop light from escaping from a point 15 km from the center of the Sun.

Escape velocity boils down to a function of mass and distance. When you compare "the Sun" and "a solar mass black hole", you've kept mass the same but varied the distance (and thus changed your answer). When you compare "the center of the sun" and "a solar mass black hole", you've kept distance constant but varied the mass (and thus changed the answer).

So, your original concept of density is basically correct. However, this should not be confused with the idea that black holes (in reference to the volume contained by the event horizon) need to have "high" density. Normal matter (of a given density) increases mass by the cube of radius. Black holes increase mass proportionally to radius. If you take a ball of clay of radius r and mass x, then a ball of clay with radius 2r has mass 8x. If you swap "ball of clay" with "black hole", then mass 8x black hole has radius 8r. Put into more practical terms, envision a sphere around the solar system, out to 100 AU (three times the orbital radius of Neptune). Fill that sphere with sea-level pressure air. The solar system is now a black hole.

Now, as for the original answer: black holes "emitting" light do so from their accretion disks, which always lie outside of the event horizon. Nothing is emanated from within. Even Hawking Radiation only works when particles form outside the horizon. — Lomn 19:08, 2 April 2009 (UTC)

Ayacop, I don't understand what you mean by "BH emitting light, it's always from inside its event horizon". Black holes don't emit light. Are you referring to Hawking radiation? A Quest For Knowledge (talk) 20:20, 2 April 2009 (UTC)

if its within the event horizon, how would we know if it emitted light or not? 65.121.141.34 (talk) 20:23, 2 April 2009 (UTC)

Now let's look at ways the perception of black holes as "cosmic vacuum cleaners" may be correct:

1) While it's true that a black hole has no more gravitational attraction at great distances than a star of equal mass, that neglects the fact that most black holes have a greater mass than most stars. In fact, most stars have insufficient mass to ever form a black hole. There are also supermassive black holes at the center of spiral galaxies which are millions or billions of times more massive than any star.

2) Stars tend to give off more mass than black holes, via conversion to energy which is emitted as light, etc., solar wind, and sometimes violent explosions like novae and supernovae. Black holes can lose mass due to Hawking radiation, but this is only significant portion of the mass for small black holes. Thus, most black holes can be thought of as one-way doors, unlike normal stars. StuRat (talk) 16:28, 3 April 2009 (UTC)

source of dietary cholesteryl esters?

As I was studying the enzyme bile acid-activated lipase, it says it degrades cholesteryl esters in the small intestine. But where do these come from? Do they always come from eating animals? Are there plants that contain amounts of cholesteryl esters? --Ayacop (talk) 18:20, 2 April 2009 (UTC)

Just to be safe you are talking about Bile salt dependent lipase right? Although not specifically "cholesteryl esters" you may want to look at dietary sources of cholesterol. I am not familiar with cholesterol biochemistry, so I don't know what form the majority of cholesterol is in when it is absorbed in the small intestine. It might be that cholesteryl esters are a storage or transport form of cholesterol. Plants do synthesize some cholesterol (some sources say otherwise but they're wrong) but it is very little compared to animal cells. You may also want to take a look at phytosterols. As dietary contributions go (assuming an omnivorous diet), cholesterol from plants is negligible compared to other sources (like the butter you cook your vegetables with for instance). Sifaka ^talk 19:08, 2 April 2009 (UTC)

Genius

Looking for any valid statistics on people who are labeled a genius of some sort (mathematical) and the possibility of having a personality/mental disorder/dysfunction. Also, any statistics, say a mathematical genius, to have children who are supra-intelligent. --Reticuli88 (talk) 18:41, 2 April 2009 (UTC)

I don't know whether you'll find much in the way of statistics. There are an awful lot of smart people (including MANY mathematicians) with Asperger's syndrome shading into borderline Autism - but because it's a spectrum condition, there is no hard definition of who has it and who doesn't. It's a matter of degree. Of course there are mathematicians who have pretty serious mental conditions - John Nash is the one that always leaps to mind because his story is told in the movie A Beautiful Mind. His paranoid schizophrenia is serious matter - but that didn't stop him from earning a Nobel prize. SteveBaker (talk) 20:11, 2 April 2009 (UTC)

As an extra comment, that film is my favourite of all time. Excellent story, thoroughly recommended. Cyclonenim :  Chat  20:49, 2 April 2009 (UTC)

Yep - all the better because it is 100% true. I like that Prof Nash still points to people he hasn't met before and asks people he knows whether they are real or not. He does it without a shred of embarrassment - and when he finds that some of the people he meets are not actually real - he happily ignores them and carries on with life! I think it takes the temperament of a good mathematician to be able to do that. Most of us would be too freaked out to cope. SteveBaker (talk) 21:02, 2 April 2009 (UTC)

Well, 100% true except the bit that shows him taking his medication voluntarily. According to the real-life Nash, he rarely ever took it unless forced to, and recovered with his own will as you described above. Now that's persistence. Cyclonenim :  Chat  23:46, 2 April 2009 (UTC)

I was under the impression that he didn't actually have visual hallucinations, just auditory. As brilliant as that film is, it is heavily dramatised. --Tango (talk) 05:12, 3 April 2009 (UTC)

People who have worked with him have told the story that he will (on occasion) point to some stranger in the room and ask everyone else: "Is this person real?" - and on much rarer occasions, he'll point to an empty piece of space and ask the same question. Assuming those reports are true - then this can hardly only be an auditory hallucination. SteveBaker (talk) 12:40, 3 April 2009 (UTC)

The our article needs correcting. --Tango (talk) 00:35, 4 April 2009 (UTC)

There is also Kurt Gödel, who starved to death for fear of being poisoned. G. H. Hardy who hated looking at his own reflection. Alas, I don't have any statistics, however. --TeaDrinker (talk) 21:40, 2 April 2009 (UTC)

It all depends on what you call intelligence. If you consider social abilities a form of intelligence, not many aspies would fall under the category intelligent. So as many people only understand math when you explain things to them clearly, step by step, aspies only understand social dynamics when you explain everything (even knowledge that other people take for granted). Since Asperger's syndrome has rather being defined recently, I don't believe you'll find many serious diagnosis of highly skilled mathematicians with it. --Mr.K. (talk) 11:26, 3 April 2009 (UTC)

It is often said that aspies don't know how to have social relationships. Actually, I think it's that they don't want to have social relationships. They get no pleasure from it. They regard social relationships as a chore and a nuisance – something they have to force themselves to do. —Preceding unsigned comment added by 98.21.105.25 (talk) 11:45, 3 April 2009 (UTC)

It's both. As an Aspie, I strongly dislike having to meet and get to know people who I don't already know well. When I do have to do it, I'm not good at it. (Although training can cover the latter to some degree - and I'm getting pretty good at faking it). Furthermore, it's not just a matter of some diffuse inability - many aspies (myself included) are completely blind to things like body-language, facial expressions and some linguistic subtleties like sarcasm. I really, deeply, hate going to parties for example. A party is an event designed solely in order that people meet and interact for no especially well-stated reason - we frequently use alcohol at these events to make that interaction more intense - and that amount of forced interaction is something I strongly prefer to avoid! My only reaction at such events is to try to find a way not to have to be involved - this is sometimes mistaken for 'shyness' - but that's not it. However, I think it's a BIG stretch to say that social abilities are "a form of intelligence". Ants and Bees have really great social relationships - but we don't generally call them "intelligent". There is a movement to get all sorts of human behaviors labelled as "forms of intelligence" - I've heard of teachers talk about "body posture intelligence" as an attribute of good dancers who are otherwise as dumb as a bagful of anvils - but that's entirely so that the teachers don't have to go around labelling people as "unintelligent" just because they can't do IQ tests or crack open a book to learn something. However, that's not the usual definition! Anyway - the OP specifically wants to know about 'mathematical geniuses' - and social skills most certainly have nothing whatever to do with that! SteveBaker (talk) 12:40, 3 April 2009 (UTC)

The amount of social interactions by humans and the complexity of these are not comparable with the social life of any other creature. Human social interactions require that you integrate all these things cited above - body-language, facial expressions and some linguistic subtleties - and much more. They are far away from a binary communication style. I don't see any problem labeling all human abilities as a form of intelligence, since all of them require processing of information of some kind. Evenly I don't see any problem admitting that animals process certain kinds of information. Some of them - like smell information - even better than us. Others - like language - only at a very primitive level, if we can speak of language in animals at all. According to the intelligence article, there are many definitions of intelligence. I would go with the intelligence = processing of information. Other definitions are probably so broad and badly defined that you could call any one 'intelligent' or you would like to guess who is intelligent or measure it with some dubious IQ test. The definition above would imply multiple types of intelligence - as many as types of information probably. Many, many people could be terrible processing one kind of information type and excel at other kinds. So, it would not be a surprise finding an aspie good at mathematics, a field that strives to define everything as precise as possible and everything has a clear purpose. There is more information aboutmultiple intelligences in the corresponding article.--Mr.K. (talk) 15:51, 3 April 2009 (UTC)

Are aspies who are good at math, also good at fuzzy math? (In fuzzy math things are not precisely defined.) —Preceding unsigned comment added by 98.17.36.180 (talk) 20:44, 3 April 2009 (UTC)

I assume any aspies who work in fuzzy maths are good at it. Fuzzy mathematics (which is, as far as I know, just as precise as the rest of mathematics) is a tiny field; I've never encountered anyone who worked on it. Algebraist 20:52, 3 April 2009 (UTC)

Are aspies good at stistics, in which things are not precisely defined?

The person who springs to mind in this field is Simon Baron-Cohen, if you look him up on Google Scholar you will get heaps of academic papers on autism. This study on the link between Autism and Engineering might be of interest to you. There is also this article on the BBC site. SpinningSpark 01:17, 4 April 2009 (UTC)

As a family therapist, some of the most challenging yet rewarding clients are those on the Asperger's continuum. An Aspie's difficulty with (or disinterest in) social skills can easily carry over into this forum where replies are at times given in a very rude and condesending manner (especially when an OP asks about Creationism vs. Evolution). So, social skills can be more than just face-to-face interactions.

As for IQ, this is only a measure of how well one is able to complete IQ tests. It was not that long ago where IQ tests had a cultural bias which often led to non-white, non-western persons not doing as well as the white westerners the IQ was designed by.

As for multiple intellegences, I would suggest that there needs to be a balance. We can't just give some arbitrary characteristic an "intellegence" name (I.E. "posture intellegence") just to make people feel better! So, while some people may be more inclined to mathematics ("math intellegent") while others are more artistic ("visual/spacial intellegence")or even people oriented ("emotional intellegence" or "social skill" intellegence - I am much better at the former than the latter)I would suggest that it is better to focus on our strengths. Thus, I became a therapist because I really am a klutz at math, mechanical things and the like. —Preceding unsigned comment added by 74.12.66.165 (talk) 21:01, 4 April 2009 (UTC)

Creativity and mental illness

It appears that a disproportionate number of creative artists considered "great" in their fields have suffered from bipolar disorder - especially poets, and among poets, especially Lord Byron. There's a good book about this by creative, bipolar psychiatrist Kay Redfield Jamison, called Touched with Fire. It's an excellent read. -GTBacchus^(talk) 16:35, 5 April 2009 (UTC)

Abiogenesis vs Evolution

I need a WP:RS that a) explains the difference between abiogenesis and evolution b) states that this is a common or popular misconception or misunderstanding. I've found plenty of blogs and forums about this, but these aren't usually considered WP:RS. The best I've been able to come up with is here [1] and here [2] but I'm hoping for something better. I'll keep looking but I thought that maybe somebody here already knows a good cite off the top of their head. If not, it's no big deal. I'll keep looking. A Quest For Knowledge (talk) 23:28, 2 April 2009 (UTC)

I would bet you could find that in one of Richard Dawkins' books - I don't have an exact ref for you though. SteveBaker (talk) 00:26, 3 April 2009 (UTC)

Ironically, I choose this item because I mistakenly thought that finding a WP:RS doing a Google search with "abiogenesis" as one of the search terms would be trivial. How wrong I was! Unfortunately, we have an editor who's apparently on a crusade to make sure that every single item in this article is correctly sourced. Not that he/she doesn't have a valid point, but they're doing a blanket removal of all unsourced items even if the information appears to be correct (just not sourced). A Quest For Knowledge (talk) 01:10, 3 April 2009 (UTC)

Yeah - in these "List of..." articles - especially those with "fun facts" like this one - there is a tremendous tendancy for junk to accumulate in the article. This SPECIFIC form of article really does have to have 100% reference coverage and a rigorous purging of unsourced junk is needed. That's only reasonably possible if all of the important stuff is referenced to within an inch of it's life. In most 'normal' articles, it is sufficient to reference only the 'likely to be doubted' facts. SteveBaker (talk) 01:38, 3 April 2009 (UTC)

I think you have to clarify the question a bit better -- this is sort of like asking for a reliable source for the difference between radio stations and submarines -- they're just different things, that's all. Looie496 (talk) 02:34, 3 April 2009 (UTC)

Sorry, I'm trying to find a WP:RS for this:

"Biological evolution does not address the origin of life; for that, see abiogenesis. The two are commonly and mistakenly conflated. Evolution describes the changes in gene frequencies that occur in populations of living organisms over time, and thus, presupposes that life already exists. Evolution likewise says nothing about cosmology, the Big Bang, or the origins of the universe, galaxy, solar system, or Earth, although the term 'evolution' in the sense of a slow unfolding is used to describe such processes, e.g. Stellar Evolution, Cosmic Evolution." A Quest For Knowledge (talk) 02:50, 3 April 2009 (UTC)

I think you just need a dictionary to verify all of that except the fact that they are commonly conflated. I'm not sure where you would find a source for that, though (finding examples is easy, but you need something more than just a list of examples otherwise you are doing original research). --Tango (talk) 05:06, 3 April 2009 (UTC)

@Tango: That's true - but you have to look at this in the context of the article that's being written here. It's a list of common misunderstandings. So whilst it's trivially easy to use the dictionary definitions of the two words to prove that Abiogenesis and Evolution are not the same thing - it's not so simple to prove that they are commonly confused or conflated. SteveBaker (talk) 12:22, 3 April 2009 (UTC)

Hmm I think it should be pretty easy to find. I mean the whole evolution vs creation myths "debate" must be sort of showing that some mix up? I would assume it must have been addressed somewhere (Just think of the possibility for someone who would want to mock the religious person/group not knowing). I am guessing one group religious that seem to have understood the difference in the catholic church, I have at least read I think that they're accepting evolution (but not accepting abiogenesis of course I guess) "post-creation" or something. chandler · 12:36, 3 April 2009 (UTC)

Discussing evolution/abiogenesis there is;

• Iris Fry, The emergence of life on Earth: a historical and scientific overview, p57, Rutgers University Press, 2000 ISBN 0813527406.
• John Augustine Zahm, Evolution and dogma, pp41-42, Ayer Publishing, 1978 ISBN 0405108745.

The above and on confusion of terms (especially historical),

• James Edgar Strick, Sparks of Life: Darwinism and the Victorian Debates Over Spontaneous Generation, pp11-13, Harvard University Press, 2002 ISBN 0674009991.

Direct dictionary definition of abiogenesis,

• Elizabeth Tootill, The Facts on File dictionary of biology, p247, University of Michigan, 1981 ISBN 0871965100.

Clear statement of confusion of the two from the other side of the debate;

• Daniel Jappah, Evolution: A Grand Monument to Human Stupidity, p21, Lulu.com, 2007 ISBN 1430324902.

Not sure about the second part of that paragraph, "evolution has nothing to do with cosmology and the Big Bang". This is like asking a for a ref that differential geometry has nothing to do with bananas. While true it is unlikely that either books on differential geometry or bananas will make this statement. Not many books covering both subjects. Seriously, I cannot really work out what that statement is supposed to be doing for the article - it is enough to differentiate evolution and abiogenesis, a contrived analogy is not really needed. SpinningSpark 15:54, 3 April 2009 (UTC)

As I was looking for cites last night, I was jokingly thinking to myself that Google should come up with a reliable sources search engine. Then I discovered that Google does let you create your own custom search engine [3]. So, I started creating a Reliable Sources Search Engine. I realize the futility of creating anything that is even remotely comprehensive, but as I was sifting through a bazillion Google hits (many of which were blogs and forum posts), I think that something that narrows down the hits might be useful (to me, anyway). My custom search engine is here [4]. So far, I have about 20 sites that are generally considered to be reliable per WP:RS standards. I left some obvious ones off such as www.abcnews.com since ABC News allows readers to add comments to a news article and I'm not sure yet how to get the search engine to distinguish between article content and user comments. I've left the search engine open so if anyone wants to contribute to this search engine, feel free. A Quest For Knowledge (talk) 15:51, 3 April 2009 (UTC)