Wikipedia:Reference desk/Archives/Science/2008 April 14

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April 14

how was leika the space dog "supposed" to die?

did they intend for laika to starve to death or what? —Preceding unsigned comment added by 79.122.58.58 (talk) 01:22, 14 April 2008 (UTC)

According to Laika, The Russian scientists had planned to euthanize Laika with a poisoned serving of food. --Bavi H (talk) 02:02, 14 April 2008 (UTC)

Is this true?

Is this video [1] at all true? Could you use a cd-rw to do this? thanks everyones —Preceding unsigned comment added by Its hard to believe (talk • contribs) 11:01, 14 April 2008 (UTC)

Hmm, did you read the comments? Like the parts that even getting a reflection of the laser into your eye for 1/1000 of a second can cause permanent blindness? Aeluwas (talk) 11:52, 14 April 2008 (UTC)

Thats not really answering the question. I did read the comments but one can never fully trust them, that is why I asked here. I am simply looking for a yes or no, although this being the science desk I was hoping for some explanation of the device, and anyones thoughts on other similar things. Thanks all —Preceding unsigned comment added by Its hard to believe (talk • contribs) 15:22, 14 April 2008 (UTC)

There was an article about this in Make Magazine recently. Apparently it's completely true that you can get lasers capable of doing things like popping dark colored balloons and lighting matches out of a dvd burner. (A couple hundred mW.) You'll need to supply your own power supply, of course. Obviously, you'll want to make sure you've got the right eye protection for this. Accidentally pointing this at a shiny object could be very bad. (Your eye protection needs to match the frequency of the laser you're using. Otherwise it does nothing.)

"Could you use a cd-rw to do this?" Yes, but unless you're familiar with handling high powered lasers you shouldn't. According to the WP article CD-RW drives use infra-red lasers which, of course, are invisible. Besides being less fun, a non visible laser can be dangerous simply because it's hard to tell if it's on. Our article on DVDr implies that it uses a visible red laser. Still might blind you, but at least you can tell if it's on. APL (talk) 15:59, 14 April 2008 (UTC)

Note that most or all DVD drives also need a infrared laser so they can read and (for DVD+/-RW and combo drives) write CDs (read the warning labels, they will usually say visible and invisible). Whether they use a seperate laser or simply have a way of changing the frequency of a single laser I'm not sure although from a quick Google it's apparently the later. Also bear in mind you will almost definitely need a R/RW laser since they are AFAIK much higher power. Nil Einne (talk) 19:18, 14 April 2008 (UTC)

There is a website that has pretty strong laser pointers here: http://www.dragonlasers.com/catalog/index.html I'm not sure if they are strong enough for burning anything, maybe they are just extremely expensive, but at least they have some kind of protection. --helohe (talk) 21:40, 14 April 2008 (UTC)

What exactly happens when you say "Well hello, newly constructed neuropathway!"?

<moved from miscellaneous desk Julia Rossi (talk) 11:55, 14 April 2008 (UTC)>
Does a new neuropathway form "recognizing" the acknowledgement unbeknownst to the original , kinda like a babys relation to it's birth certificate? Or somehow evolve by assimilating the new information into it's chemistry? Does it "know" what I'm hoping to achieve with this question and then question "itself" philosophically? Does it gain a new mind? Is all mind chemistry? Sam Science (talk) 19:21, 13 April 2008 (UTC)

I have no idea what you're trying to achieve with this question. I assume you're talking about whether or not there's a paradox in self-reference in the brain, like if I think about making a connection and a connection is made, I can form a contradiction. Well, it doesn't appear possible, for two reasons. First is that we don't appear to have any conscious feedback about what is going on in our brains, so we have no awareness as to the connections that are made. Indeed, to have such awareness, circuitry would have to be modified whenever circuitry is modified. This doesn't necessarily cause a paradox because of the second reason: normalization. It appears that most processes in the brain are normalized - that is, nerve cells are not usually overwhelmed or underwhelmed by the signals they receive, so even if one were to form an infinite feedback loop in the brain, the signal would either reach a peak and stay there or fade as new signals come into play. The only other possibility may be cell death or pruning of a now-useless connection. SamuelRiv (talk) 01:45, 16 April 2008 (UTC)

I'm not exactly sure what I was trying to achieve here either. Self referential puzzle? Finding the "Planck root", if you will, of all conscious phenomona? Existential crisis? Not sure. It just gripped my mind a few days ago and wouldn't let go. Thank God for you guys! Sam Science (talk) 01:58, 16 April 2008 (UTC)

People hear you saying "Well hello, newly constructed neuropathway!" and think that you're a genius (or insane). :-) Ilikefood (talk) 22:32, 16 April 2008 (UTC)

Red deer

The youngs are called both calves and fawns in this article. The first seems to be the usual term; is the latter a correct variant or a mistake? --KnightMove (talk) 12:37, 14 April 2008 (UTC)

Fawn (noun): a young deer; especially : one still unweaned or retaining a distinctive baby coat. (Merriam Webster) --121.83.135.121 (talk) 13:57, 14 April 2008 (UTC)

Thx, but this doesn't help. Depending on respective species, young deer are called fawn or calf, see Deer#Etymology. The question is whether fawn is accepted for Red deer, where calf is the most common term, or not. --KnightMove (talk) 15:11, 14 April 2008 (UTC)

The right place to raise the issue of which to use in the article is, of course, the article's talk page, here. Another good place to go is the project page of any WikiProject that has staked a claim on that same talk page. I have gone to Wikipedia:WikiProject_Mammals and asked if someone would reply here. (My opinion doesn't count, but I call pretty little spotted critters of that kind fawns.) --Milkbreath (talk) 15:33, 14 April 2008 (UTC)

This says that both are acceptable. Michael Clarke, Esq. (talk) 22:33, 14 April 2008 (UTC)

Aspartate-tRNAAsn ligase

Aspartate-tRNAAsn ligase catalyzes the binding of aspartate and tRNA(Asx) without discriminating between tRNA(Asp) and tRNA(Asn). This page says "The aspartate-tRNA(Asn) is not used in protein synthesis until it is converted by EC 6.3.5.6 into asparaginyl-tRNA(Asn)." How is this possible? Is this done by the ribosomes or is it just that the reaction aspartate-tRNA(Asn) -> asparaginyl-tRNA(Asn) is so fast that the aspartate-tRNA(Asn) concentration is never high enough to worry about translation errors? Icek (talk) 16:35, 14 April 2008 (UTC)

Most probable year of peak oil

I have two questions regarding peak oil.

• The article Peak oil and Predicting the timing of peak oil gives all significant viewpoints about the timing of peak oil. Aside from some theories like "No peak oil", most researchers predicted the timing. According to the estimation by Association for the Study of Peak Oil and Gas, peak oil will occur in 2010. I want to know which year is the most accepted year?
• What will be the fate of industry after peak oil. How many years will it take for the industry to collapse from the year of peak oil? And a little final question, will airline industry survive after 100 years from when global oil peaks? Please tell. Otolemur crassicaudatus (talk) 18:38, 14 April 2008 (UTC)

I don't know mmuch about the expected timeline of peak oil, but I thought I'd answer your last question about the future of industries based on oil once we are running very low. I have no hesitancy in saying that they will survive. That sort of difficulty will just create a need for innovation, and will provide real motivation for companies to give serious funding to developing oil-free fuels. There will also be the normal market advantages: if there is no oil, the person/group that invents a way of fuelling cars, aeroplanes and all the rest wihout oil will stand to gain an enormous amount from their work, so expect solutions to be forthcoming. There is no reason AFAIK to suggest that there cannot be an alternative for oil in all its current uses. Michael Clarke, Esq. (talk) 20:25, 14 April 2008 (UTC)

I don't know if there is a most accepted year, it's such a complicated field which involves so much 'guesswork' (for the later of a better word) and so many conflicting factors, with such a variety of suggestions and so much politics, money and COI that there's probably none. Nil Einne (talk) 20:38, 14 April 2008 (UTC)

It is not right to say that airline industry will survive. As being politically anarcho-primitivist, I support peak oil and consequential industrial collapse. At present there is no fuel outside conventional fuels for aeroplanes. And the alternative fuels are not at the level to continue the airline industry. Alternative fuel development is in its rudimentary stage and there are several problems regarding this. Survival of industry after peak oil based on alternative fuel is a subject of science fiction. Otolemur crassicaudatus (talk) 20:49, 14 April 2008 (UTC)

While it is true that it is science fiction to speculate on how the fuel crisis will be overcome, it would be naive to think that it will not be overcome. Desire and necessity drive invention and creativity, and as long as there is demand for air travel, there will be air travel. As I said, there is nothing to suggest that it will be impossible to replace oil, even if it requires different replacements for the many different uses of oil. Michael Clarke, Esq. (talk) 21:33, 14 April 2008 (UTC)

And I'm sure you're aware of the irony of an anarcho-primitivist using the internet... Michael Clarke, Esq. (talk) 21:34, 14 April 2008 (UTC)

I'm hoping that the airlines are forced to go back to Zeppelins. They're a bit slow, but they make it up with class. APL (talk) 13:25, 15 April 2008 (UTC)

Whenever reading about peak-oil and post-oil worlds i'm always reminded of (I think) a Sheikh who said "the stone age did not end for lack of stone, the oil age will not end for lack of oil" (or words to that end). The Aviation industry certainly has challenges and aviation in the future might not be the same as aviation-today, it might be vastly different in ways we cannot imagine but it will exist. Might be worth having a read of the article Aviation history - quite interesting and has a section on peak-oil ny156uk (talk) 22:35, 14 April 2008 (UTC)

Biofuel is not the solution to continue the industry. For details see Biofuel#Sustainability_of_ethanol_production and Biofuel#Soil_erosion.2C_deforestation.2C_and_biodiversity. Using biofuel to continue the industry is the subject of science fiction and some fringe theorists. Otolemur crassicaudatus (talk) 10:06, 15 April 2008 (UTC)

What a strange analogy. Did stones suddenly stop being near-free and become something that needed to be manufactured at great expense? APL (talk) 13:25, 15 April 2008 (UTC)

Thinking about that for a moment, If I can anticipate the response I'd like to add that I'm pretty sure that society uses far more stones today than it ever did back when we were throwing them at woolly mammoths. APL (talk) 13:28, 15 April 2008 (UTC)

No the point of the analogy is not about scarcity it is about development...The end of the stone age was not a result of running out of stone, it was a result of technological advancement. Similarly the quote suggests that we will not leave the oil-age because of a lack of oil, we will leave it because of technological advances. I'm inclined to agree with that logic, albeit it that it is reliant on believing mankind has the ingenuity to find a suitable replacement within the timescales of the predicted-oil we have left to utilise. Simple economics tends to suggest scarcity and high-demand increases prices, and that should spur on searches for replacements and/or reduce consumption over time as people are priced out of using oil and so seak out alternative (either in energy source or reduced use of energy) ny156uk (talk) 16:31, 15 April 2008 (UTC)

Remember that what's "magic" about oil is that it's essentially a free form of energy. In its refined forms it's great for fueling cars and trains and aeroplanes, but what's vastly greater about it is that it taps millions of years of accumulated, concentrated solar energy. It costs a certain amount of money to get it out of the ground and refine it, but the cost is far less than its worth in dollars per joule. (That's precisely why the oil companies are so profitable.)

There are lots of alternative fuels we might use. The important question isn't whether they'd work, or how compatible they are or aren't with our existing fuel distribution infrastructure. The key question is whether they're an energy source or a transfer medium. If they're just a transfer mechanism (like hydrogen or electricity), then their use as a fuel merely begs the question: where does the energy come from to create them?

There are lots of sources of energy, too, of course, but when it comes to the long-term prognosis for our energy-hungry lifestyle, only one characteristic matters: is it renewable/sustainable, or not? Right now, we're still very heavily dependent on nonrenewable energy sources. The question is, can we wean ourselves off of these, and on to wholly renewable sources, before we burn up all the nonrenewable sources, and crash? (An important sub-question is, do we get there by finding additional renewable sources that will enable us to match our current nonrenewable usage rate, or are we going to have to figure out how to get by with less?) —Steve Summit (talk) 01:23, 15 April 2008 (UTC)

The answer is no. Expect some fringe theorists, Kardashev scale etc. it is not possible to find additional renewable sources that will enable to match the current nonrenewable usage rate. Otolemur crassicaudatus (talk) 10:17, 15 April 2008 (UTC)

Well, there are degrees of "renewable". Not even the Sun is renewable forever. But if it's good enough for an energy source to go for quite a long time -- long enough, hopefully, for our descendants to figure out something else before it's all gone -- then breeder reactors should last us quite a while, especially if we use both the U-238 and thorium cycles. --Trovatore (talk) 18:04, 15 April 2008 (UTC)

Reading and near-sightedness

It is often said that if you read a lot when you are young, you have a higher chance of becoming near-sighted. Is this true? I mean, has there been studies on this that have shown causality? I sort-of find it hard to believe that simply focusing on something that's near to you fundamentally changes the shape of the eye and the lens. It does fit me, I read heckuva lot as a kid, and if you're more than 2 meters away from me (and I don't have my glasses), I basically have to identify you by voice. Then again, pretty much everyone in my family has glasses so that'd be an argument for genetics (although, everyone in my family reads a lot too...) 83.250.207.154 (talk) 18:45, 14 April 2008 (UTC)

I personally don't think so, but I don't have any evidence to back it up. I'm going with genetics all the way. Neal (talk) 19:07, 14 April 2008 (UTC).

There is a section on this in the article for Near-sightedness. I, too, read many books as a child. However, my myopia is so severe (everything beyond 5 centimeters is horribly blurry) that I highly doubt something as simple as reading could have caused it. Since myopia is caused by the elongation of the eye, and increases steadily over time regardless of activity (at least in my case), I would have to say it has a lot to do with genetics. 206.252.74.48 (talk) 19:56, 14 April 2008 (UTC)

I have coloboma of the chorrhoid layer and have always had to read very close; I've been reading extensively since age 3 with no chnge in my eyes. So, I agree, it isn't always the case.

I use to tell people that it was like a baseball pitcher's arm, and mine was like a Nolan Ryan. I think that's true - just as some pitchers can throw gobs of innings, others can't. Similar, some heavy readers need reading glasses, others don't. —Preceding unsigned comment added by DTF955 (talk • contribs) 21:18, 14 April 2008 (UTC)

What if it's working the other way: those children who have myopia can't watch objects that are far from them so instead read books which are close? – b_jonas 09:01, 15 April 2008 (UTC)

But that wouldn't explain children who had regular eye tests throughout childhood (as are freely available in the UK, for example), read a lot throughout childhood, and whose vision can thus be known to have been good before they started reading intensely. Certainly I know that chickens tend to develop myopia if kept in conditions that prevent them looking at distant objects when they're still developing, and this can be resolved by allowing them occasions to focus on the distance. In humans it is harder to resolve, and too much close-focusing without distance-focus is nowhere near the whole picture, but there is some evidence that it can be a factor. I'd guess that there's a strong genetic component that affects whether you're susceptible to certain sorts of short-sightedness, and that certain forms can be exacerbated or even caused by too much close-focusing without distance-focusing, if you're genetically susceptible, but it doesn't cover all readers or all those with sight problems. 130.88.140.1 (talk) 10:42, 15 April 2008 (UTC)

Well, a chicken in a pen during its entire formative years and a young person who reads a few hours a day at most is quite a different situation. --Captain Ref Desk (talk) 16:36, 16 April 2008 (UTC)

I have written a school project about vision recently. I don’t know if my information is 100 per cent true but in young age eye has the highest ability to adapt. When you reading your eyes’ muscles are strained very much. Eye can adapt to it: it’s growing up and can see close-located subjects without strain, but myopia appears.

I think you should visit this site: [2]. --Juliet16 (talk) 06:04, 18 April 2008 (UTC)

Strawberry flavouring

Why is it so difficult to chemically replicate the flavour of strawberries? I ask because no strawberry-flavoured food that I've ever eaten tasted like strawberries, yet I've had other foods that were flavoued artificially and were accurate gustatory imitations. is strawberry just a very compex taste? Are certain tastes easier to synthesise than others? Michael Clarke, Esq. (talk) 21:29, 14 April 2008 (UTC)

Yes, some are easier than others. Artificial vanilla is wonderful, while artificial cherry and grape are also awful, or at least completely unlike the natural flavors. I don't know why, however. StuRat (talk) 23:27, 14 April 2008 (UTC)

I think it would have to do with the complexity of the chemical reactions. For example, vanilla's taste and smell is primarily from vanillin. By contrast, the smell of a strawberry is supposed to be the result of a reaction between 350 different chemical reaction. According to Fast Food Nation:

A typical artificial strawberry flavor, like the kind found in a Burger King strawberry milk shake, contains the following ingredients: amyl acetate, amyl butyrate, amyl valerate, anethol, anisyl formate, benzyl acetate, benzyl isobutyrate, butyric acid, cinnamyl isobutyrate, cinnamyl valerate, cognac essential oil, diacetyl, dipropyl ketone, ethyl acetate, ethyl amyl ketone, ethyl butyrate, ethyl cinnamate, ethyl heptanoate, ethyl heptylate, ethyl lactate, ethyl methylphenylglycidate, ethyl nitrate, ethyl propionate, ethyl valerate, heliotropin, hydroxyphenyl-2-butanone (10 percent solution in alcohol), a-ionone, isobutyl anthranilate, isobutyl butyrate, lemon essential oil, maltol, 4-methylacetophenone, methyl anthranilate, methyl benzoate, methyl cinnamate, methyl heptine carbonate, methyl naphthyl ketone, methyl salicylate, mint essential oil, neroli essential oil, nerolin, neryl isobutyrate, orris butter, phenethyl alcohol, rose, rum ether, g-undecalactone, vanillin, and solvent.

So yeah, it's no easy feat to replicate the flavor or smell of a strawberry. bibliomaniac15 Hey you! Stop lazing around and help fix this article instead! 23:35, 14 April 2008 (UTC)

Contrast the above list of ingredients with Pineapple, banana and a lot of other fruits that can have thier flavoUrs replicated by one ester. The esterification reactions are a very common high school chem experiment, differences in one carbon can result in a totally different smell.

Oh and btw that list by Fast Food Nation in no way means that artificial strawberry is less healthy than natural strawberry flavour.--Shniken1 (talk) 10:54, 15 April 2008 (UTC)

Does anyone know where to find strawberry-flavored strawberries? I find that most strawberries taste more like straw than like berry. --Trovatore (talk) 18:19, 15 April 2008 (UTC)

Supermarket strawberries are so tasteless because they have to be grown real fast to get that ridiculously low price. Although they have managed to develop varieties that turn red fast, there is insufficient time before picking for the flavours to develop. My sister recently gave me some from a small independant grower in cornwall (England) last time I visited. Delicious, what a surprise, I had forgotten what a proper strawberry is actually supposed to taste like. So my answer is Cornwall, but there are probably other places you can get them. SpinningSpark 18:45, 15 April 2008 (UTC)

I remember a controversy (possible lawsuit?) back in the eighties or so about "natural cherry flavor". IIRC one manufacturer of natural cherry flavor sued another one, claiming the second one's process was insufficiently "natural". The thing that stuck with me was that (again, if I recall correctly) neither plaintiff nor defendant used any actual cherries to make "natural cherry flavor" -- they used bitter almonds, and somehow cleaved off the sugar molecule and the cyanide group from the amygdalin therein contained to make benzaldehyde. You would search the news stories in vain for any suggestion that benzaldehyde derived from almonds, even if natural and even if it tasted like cherries, was not natural cherry flavor. --Trovatore (talk) 20:58, 15 April 2008 (UTC)

Right. "Natural flavors" and "artificial flavors" are exactly the same chemicals but the question is how they are derived (synthetically vs. not). The terminology of "natural" v. "artificial" has nothing to do with whether the flavor is derived from anything relating to what it is supposed to taste like. It's a very bizarre distinction, if you ask me—I suspect (as does the author of Fast Food Nation, a fascinating book linked to above) that consumers are basically being duped and responding to the idea that something "natural" in this case is better for them or more "authentic", whereas the facts are pretty far from the case. --Captain Ref Desk (talk) 16:40, 16 April 2008 (UTC)

I generally agree with you on the "natural" versus "artificial" debate, but flavors are an exception. As noted above, for all but the simplest flavors, at least, scietists have thus far been unable to get the balance of chemicals anywhere near close to the natural flavors. Thus we end up with "strawberry", "grape", and "cherry" flavors that wouldn't fool anybody with a functional tongue. StuRat (talk) 17:15, 17 April 2008 (UTC)

Well, but they're not going to get much closer to the real taste of cherries by using benzaldehyde derived "naturally" from bitter almonds, I think. --Trovatore (talk) 18:31, 17 April 2008 (UTC)

Sexual selection in humans

I was reading The Selfish Gene and was struck by the passage where Dawkins raised the question of why human females are the ones who have to wear make up, dress up, doll up, etc. when in almost every other species, the worth of the female egg and related factors has made females the sought after sex. Thus we have the peacocks and big cat suitors who have to compete for female attention by growing flashy tails or muscles. The sought-after sex gets to be drab because they don't need to be sexually attractive. Why the opposite in humans? Imagine Reason (talk) 22:21, 14 April 2008 (UTC)

I hope someone chimes in with a good answer. All I can say is, Dawkins may be engaging in cultural tunnel vision. There are other cultures where females do look drab deliberately, ranging from wearing conservative clothing and scarves to completely covering themselves from head to toe, with no skin visible. The same is true for any culture in history that regarded women as property. ~Amatulić (talk) 22:27, 14 April 2008 (UTC)

Good point, but it's also not true that all male-dominated cultures make women drab. The women in late feudal China suffered things like footbinding, but they were doing it to doll up. And even if it is only Western culture that sees women pretty themselves while metrosexual males are looked upon suspiciously, why? Imagine Reason (talk) 23:05, 14 April 2008 (UTC)

However even in Western culture, there is still some expectation for male grooming. Cologne, some degree of style, a decent hair cut etc are usually expected. A male who looks like he just woke up including in clothes is unlikely to find many takers, unless perhaps he has some other special charecteristic like being very rich. Nil Einne (talk) 20:42, 16 April 2008 (UTC)

(After Edit Conflict)

I would think that in humans it is different yet similar. Due to our evolutionary adaption, we show our peacock feathers in a different way. Such as it is considered, in virtually all cultures, that the male should be the persuer of females. That is; men should woo women using gifts, poetry etc., and this is why people often think women being forward to be unusual. I think that women using their physical attractiveness is more to do with the human male's "visual" sexuality. Which, as far as I know, is to do with the ease of discerning "the hairless ape's" suitaility for childbirth by looking. I may be rambling a bit, but I find the questing fascinating! :-) Any more ideas? Fribbler (talk) 23:08, 14 April 2008 (UTC)

I would say the diff is that for most species the male is simply a "sperm donor", so their health and fitness (demonstrated by some elaborate display), is the only important factor to consider. In humans, on the other hand, males have historically been important in providing for the wife and children, as well. This means that being a good provider is also an important trait. Faithfulness is also important, since children wouldn't have been likely to survive, until relatively recently, if the man runs off with some other woman. And we can also throw in kindness, since a man who beats his wife or children would decrease their chances of passing on their genes. So, all of this means that attractiveness of a male is only one of many factors women considered.

Conversely, if the man is going to invest a lifetime in raising children with a woman, he needs to be sure she is a good choice, and youth and attractiveness are indicators of the woman's health and ability to have children. In the "sperm donor" spcies, on the other hand, if a male chooses a poor mate, it's only 15 seconds out of his life, so no big deal. This makes them just go for quantity and not much care how attractive, young, or healthy any female is. StuRat (talk) 23:10, 14 April 2008 (UTC)

Good points, all, but none of the features mentioned are remotely exclusively to humans. In particularly, males pursue in most other species and monogamous and costly pairings are common in nature. Imagine Reason (talk) 23:25, 14 April 2008 (UTC)

Indeed. But were you not looking for the aspects that were unique to humans? That we were unusual? I thought we showed that the same rules apply. Albeit differently?Fribbler (talk) 23:28, 14 April 2008 (UTC)

Sorry, I don't understand. Yes, I'm looking for the aspects that differ, but I don't see them yet. I don't see what has driven the females to pretty themselves up especially in societies that treat them more or less equally. Imagine Reason (talk) 23:36, 14 April 2008 (UTC)

Well for one thing, the romantic-love-dating sort of thing is fairly unique to societies where males and females are more or less equal. Without this, the need for females to pretty themselves up is somewhat reduced. In many other societies where arranged marriages or at least parental involvement is common their concern over how 'pretty' the female is is often not that great. Also bear in mind with the changes in technology and culture, many of the things which used to be important, are no longer so important. For example, while the ability to cook, clean the house, take care of kids etc may have once been considered paramount for a good female partner, these are no longer seen as so important in modern societies. Even the ability so conduct oneself 'properly' as was common in high society has largely died out. Also, are you sure that there is anything unique about humans? I would expect in most animals where monogamous and costly pairings are the norm (and the sex ratio is close to 1:1), both sexes play an important selection role in choosing the mate. It's predominantly in polygynous or sperm donor animals (where the male is either only a sperm donor or alternatively has multiple female parners) where the males choice is of little note because in these cases, females do not have to compete (that much) for a mate. Rememeber as well, as has been noted males and females definitely do have to be 'flashy' to compete for mates in human societies. Males may not have to pretty themselves up so much, but they do need to have stuff like a good income, good body, be well manered etc. Nil Einne (talk) 21:06, 16 April 2008 (UTC)

Ah, I think I see (though maybe not :-)) I'm going to focus in on the societal issue. In unequal societies (by western standards), women are considered to be too sexually seductive to be dislayed in public. That is, their attractiveness would lead to them being raped indisciminately (a poor opinion of the males in these areas, in my opinion), and it isn't particularly a question on genetics as it is a question on culture. Hence the 'drab' clothing or appearance. It is considered that women who display themselves would invite 'unwanted attention' from men other than their husbands. Am I getting close to answering your question at all? Fribbler (talk) 23:46, 14 April 2008 (UTC)

Indeed culture is keeping those women oppressed, but I guess my point is that other animals do not need to force the issue for females to be drab. The natural state for other females is for males to be physically attractive. Perhaps in men appearance has fallen behind as an indicator of reproductive fitness, while it remains a good indicator in women? Imagine Reason (talk) 00:16, 15 April 2008 (UTC)

I don't think that is 100% accurate. While there are definitely some people in some cultures who argue that women shouldn't be sexually seductive because it will lead to them being raped, many others including some feminists in such cultures argue it removes the need for females to be 'sexually seductive' to attract a partner and instead encourages males to look for other things like intelligence, compatibility etc in their female partners Nil Einne (talk) 20:36, 16 April 2008 (UTC)

My take on the whole thing would be that even though the females may have to dress up and look nice to attract a mate, this is no different from the animal kingdom. Men still compete for women, pretty viciously at times, and often go through elaborate courting processes as was mentioned above. The women dress up in order to attract the best possible mates, as if they look bad then the best mates will ignore them. This is the same in the animal kingdom: the males don't put on displays for the females they don't want. I would interpret the female "dolling up" as similar to preening in female animals, while it is still the male of the species who must go through the elaborate courtship rituals and display his worth to the female. I think human courtship has gotten to the point where in many societies there is not a strict male or female balance of power. To borrow from the frogs and the way male frogs will guard a spot for the female to lay her eggs, and then the female will choose one, in humanity who would take which role? There are many deep sociological issues here, especially involving the subjugation of women. Often men have been able to choose women on a whim, and the women had no say. But now, women are increasingly in control of relationships: it's the man who proposes, and the women who rejects. seems quite a bit like the frogs to me, once you get past the complicated nature of human interaction. Michael Clarke, Esq. (talk) 23:58, 14 April 2008 (UTC)

Indeed, Mickey C. Though I would say that male choice of a partner on a whim was limited to the nobility of world nations. It is indeed very sociological, and complex! We are a complex species, that twists the rules of nature to suit ourselves. Fribbler (talk) 00:09, 15 April 2008 (UTC)

So you're saying that men are doing similar things to building nests. Hmm. Imagine Reason (talk) 00:16, 15 April 2008 (UTC)

Oh yes! Definately! Nest building shows suitability as a providing parent. The human male uses his status as a nest. Displayed by car ownership, house ownership, income etc.; nest building is merely a sign of providence. It all boils down to what support mechanisms one can provde to ones offspring. The requirement adapts to situations Fribbler (talk) 00:23, 15 April 2008 (UTC)

Also note that many other animals don't have flashy males. There are some birds (like penguins) and many mammals (like cats and dogs), where it's not even easy for us to tell the males from the females without "noting their particulars". StuRat (talk) 01:56, 15 April 2008 (UTC)

Yeah, I need to remind myself of that. I think though those females are not flashy either. Imagine Reason (talk) 03:07, 15 April 2008 (UTC)

Just a note, but Darwin himself noted this difference between humans and other animals in Descent of Man when he really exposited on sexual selection the first time. I forget whether he gives his own explanation or not. --Captain Ref Desk (talk) 02:34, 15 April 2008 (UTC)

I've always thought that a man's beard was akin to to a lion's mane in flashiness. Men tend to have naturally longer eyelashes and hairier bodies. Remember also that physical competition is part of the equation so stronger looking men tend to be more attractive to women. This is, of course, the natural state and cultural training can adjust such things. — Ƶ§œš¹ _{[aɪm ˈfɻɛ̃ⁿdˡi]} 21:09, 15 April 2008 (UTC)

I don't know what Dawkins take on it is (and he's not the be-all-end-all of interpreting evolution, BTW), but one thing to keep in mind is that in other species (even in closely related primate species) the female has a very visible display of estrus, for example getting bright red, swollen reproductive organs (I would have provided specifics, but I don't want to Google "red swollen reproductive organs" ;), presenting themselves in a certain way, etc. The concept is that if you can successfully reproduce less than 10% of the time, you don't want to be harassed by males seeking to mate the other 90% of the time. In addition, if estrus is staggered (different females come into heat at different times) you'll get better mate selection if the males know who to fight over. Note, however, that Humans are distinctly lacking in any sort of noticeable estrus signal. One theory floated on this is that humans benefit from the ambiguity over fertile times - if the male doesn't know when you're fertile, he'll stick around and provide food/other social benefits for you. Also, if he's clueless as to who you mated with when you were fertile, he won't know which matings were successful, so he can be conned into helping raise Mr. Svelte's child. So there may be an evolutionary benefit to keep looking like you're young, fertile, and sexually receptive. (For a tangible example, go to any college bar - attractive women can go *years* without paying for any drinks.) -- 128.104.112.85 (talk) 00:01, 16 April 2008 (UTC)

And of course all this is further complicated by such strange things as men paying strippers more when they're in the fertile portion of their cycle, even though they don't 'know' when that is. 130.88.140.121 (talk) 08:53, 16 April 2008 (UTC)

I really like Nil Einne's answer. If I may paraphrase it, women in Western culture are less selected for their homemaking and childcare activities now, and beauty may have thus have arisen as a criterion. Imagine Reason (talk) 13:34, 17 April 2008 (UTC)

Macaw - why's she so bad at walking on the floor?

When she walks on my hardwood floors or on something like a tabletop, she walks like a person in shoes would walk if they were on an ice rink. Seems to be a real effort for her. There's nothing wrong with her legs and I keep her toenails well trimmed. It just seems to be a smooth surface problem for her. Any ideas? —Preceding unsigned comment added by 84.65.178.125 (talk) 23:22, 14 April 2008 (UTC)

It's probably because she evolved to grasp branches with her talons, so they are not designed for walking along polished floors. Michael Clarke, Esq. (talk) 23:48, 14 April 2008 (UTC)

Indeed, the curved talons of a bird are designed to cling to branches and not smooth flooring. Fribbler (talk) 23:56, 14 April 2008 (UTC)

It isn't even a question of "cling"; the bird has to spread its toes uncomfortably wide to stand upon, let alone walk upon, a flat surface.

Atlant (talk) 12:18, 15 April 2008 (UTC)

Due to the curvature of the talons, a parrot is physically unable to lay its feet flat against a hard, smooth surface. The pressure on the talon tips causes the end of the toe to lift and bend backwards at the joint - and I don't think that parrot toes were designed with bending backwards in mind. I'd imagine that it's pretty uncomfortable to walk like that for long, lack of traction against the surface aside (yes, it probably is like walking on ice to them). That said, I've owned fully-flighted small parrots (various species) that skittered and wobbled around on a glass coffee table I used to own for tens of minutes at a time whilst playing when the option was there to go somewhere else. --Kurt Shaped Box (talk) 20:33, 15 April 2008 (UTC)

Macaw question 2

How is it possible for my Macaw to eat a habanero pepper like a human would eat an apple without being effected by the heat at all? --84.65.178.125 (talk) 23:39, 14 April 2008 (UTC)

Im guessing it's to do with their tongues' perception of the Capsaicins in the chilli. They may not react to it as a mammal would. Fribbler (talk) 23:52, 14 April 2008 (UTC)

I find it odd that your macaw can do that. I had a canary once, who would eat nearly anything that was roughly the size and shape of a seed (bread crumbs, pieces of nuts, rice grains, etc.). Well, as you know, the heat in jalapeño peppers reside in the seeds. He tried eating a jalapeño pepper seed once. Just a few bites with his beak, then a violent shake of his head. He never touched a jalapeño seed again. I suspect he felt it.

Maybe your macaw just loves the sensation of "hot" foods, like some humans do. ~Amatulić (talk) 00:07, 15 April 2008 (UTC)

And how exactly did that seed get in the bird cage ? StuRat (talk) 01:46, 15 April 2008 (UTC)

It didn't. The canary only used his cage to sleep. He spent most of the rest of the day on a newspaper we kept on the countertop, admiring his reflection in the toaster, and making forays elsewhere for tidbits. Once when cutting up jalapeños, he made off with a seed. ~Amatulić (talk) 20:11, 15 April 2008 (UTC)

I wouldn't worry about it. Some commercial bird seed mixes contain dried chili seeds. My lovebird used to eat the stuff with no complaints. Don't you have to feed chillies to red canaries in order to maintain their colour anyway? --Kurt Shaped Box (talk) 20:40, 15 April 2008 (UTC)

The article on Capsaicins says in its opening paragraph that it is a mamallian response. I don't know better, but it would seem that birds could eat them easily. Maybe your bird didnt like the taste? Fribbler (talk) 00:13, 15 April 2008 (UTC)

As I recall, that's actually the point of capsaicin. The peppers "want" to be eaten by birds rather than mammals. That's because mammals destroy the seeds in the gut, thereby defeating the whole purpose from the plant's point of view. Birds don't, and, as it were, scatter viable seeds far and wide. --Trovatore (talk) 22:09, 16 April 2008 (UTC)

The only scattering done by parrots is when they throw the food they can't be bothered to eat to the ground. :) Pepper seeds wouldn't even make it past the jaws of a parrot intact. --Kurt Shaped Box (talk) 23:36, 16 April 2008 (UTC)

Well, I'm not a parrot expert, but I kind of doubt that. The last time I looked, parrots didn't actually have teeth, so they couldn't really chew anything. Even we, who do have teeth and can chew, will swallow plenty of whole seeds when eating a pepper. --Trovatore (talk) 00:32, 17 April 2008 (UTC)

If a parrot finds a seed or seed-like object, it'll shell/peel/crush it. That's what they do best. They'll often tear fruit apart and discard the flesh, just to get at the seeds. Also, parrots tend to only eat very small mouthfuls at once. --Kurt Shaped Box (talk) 00:34, 17 April 2008 (UTC)

I wouldn't be surprised if it would do that to some individual seeds. But I can't believe it'll do it to each seed in the pepper. Seems like too much work for not enough calories, especially with the juicy pepper flesh just waiting to be swallowed. --Trovatore (talk) 00:38, 17 April 2008 (UTC)

I'd have thought that the seeds were actually more calorific than the flesh... --Kurt Shaped Box (talk) 00:42, 17 April 2008 (UTC)