Wikipedia:Reference desk/Archives/Science/2007 September 1

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September 1

Solubility of Tri n_Butyl Amine in Di Chloro Methane (MDC)

Tri n-Butyl Amine.HCl remains dissolved in xylene at 50 degrees celsius, when used as an acid binder for HCl gas. What is the solubility in non aromatic chlorinated solvents like Di Chloro Methane/methylene di chloride (MDC), 1,2 dichloro ethane (EDC), chloroform etc, below their boiling points? —Preceding unsigned comment added by Mmbk (talk • contribs) 08:28, 1 September 2007 (UTC)

It will be soluble, but I haven't got a data to say how much, it's possible that the crc handbook (CRC Handbook of Chemistry and Physics) may have data like this (there should be one in a library) otherwise the searcj may be more difficult.87.102.87.15 11:34, 1 September 2007 (UTC)

Flight in young birds - instinct or acquired skill?

I've been watching the newly-fledged gull chicks flapping around awkwardly (as their parents effortlessly soar) and struggling to fly and maintain balance whilst carrying food in their beaks today. The question was raised in my head - can a young gull instinctively fly to some degree, or does it have to learn everything from scratch by trial and error and observing its parents? Watching chicks in the nest, I see them beating their tiny, downy wings and jumping up and down from a very early age, as though they are trying to grasp the basics ASAP. Different species, I know - but as I understand it, macaws raised by humans in an environment that precludes wing exercising and 'test flights' whilst young will never learn to fly properly. --Kurt Shaped Box 15:03, 1 September 2007 (UTC)

I'd say a combo of both. Wing flapping is probably instinct, but there's a lot more to flight than just flapping wings, and much of that needs to be learned. By comparison, kittens seem to have the instinct to scratch the ground after they urinate or defecate, but don't actually put this instinct to good use to bury the urine or feces (and thus hide their scent from predators), until taught by momcat. StuRat 16:03, 1 September 2007 (UTC)

Think of how humans learn to walk. We're obviously "hard wired" for walking bipedally, in the sense that our brain and bodies are arranged so that it is an easy and instictive way of getting around, but that doesn't make it an easy thing to learn how to do from the get-go. It takes a lot of trial and error to get all of those "pre-packaged" routines in sync with our legs and our eyes and our inner ear, and to get comfortable enough with them so that we can do very complex things like walking up and down stairs, dancing, etc. --24.147.86.187 16:07, 1 September 2007 (UTC)

Thanks, guys. I figured that it may have been something along those lines. It really hit home when I noticed that while the adult gulls were capable of circling (seemingly) effortlessly and barely beating their wings, the youngsters were fluttering in ragged circles and struggling to maintain level flight. I realized that the parent gulls most have an utterly *phenomenal* intuitive understanding of aerodynamics, thrust, wing loading, lift, drag, etc. The sort of subjects that might take a human years to learn, gulls can figure out in a matter of weeks by just getting out there and doing it (the older juvies fly just fine). There *must* be a hard-wired aspect to it. Amazing. --Kurt Shaped Box 19:34, 1 September 2007 (UTC)

I don't think flight is all that much more complex than other common tasks animals do. Consider people catching a ball. Seems simple enough, but we know the ball would follow a parabolic path in a vacuum but is also affected by air resistance and wind. So, somewhere in our minds we are taking sample points, calculating distance, estimating position and velocity vectors, and changing our location and hand position to catch the ball. If we asked a robot to do it there would be an astounding amount of math involved. But, for us, it's child's play, we don't even have to think about it. It's not all instinct though, it does take practice to learn the proper method. StuRat 02:11, 2 September 2007 (UTC)

I was just considering the relative risk of flight compared to other activities that animals partake in. You fail to walk, you fall down on your backside - you fail to catch something and you fail to catch something. Get the mechanics of flight wrong and you drop like a stone, with the risk of *severe* injury unless you can recover it in time. Misjudge the landing and you can very easily hit something very hard and unyielding behind your intended destination (think of birds landing on cliff-faces - or the 'pet bird and wall behind the cage' situation), again with the risk of *severe* injury. The consequences of 'failing to fly' can be far greater than the consequences of 'failing to walk'. I suppose that's a strong evolutionary incentive to get it right pretty quickly. :) --Kurt Shaped Box 08:15, 2 September 2007 (UTC)

I strongly disagree, If you are a newborn Thomson's Gazelle out on the plains of East Africa - you'd better be up and walking within a very few minutes - and running at 80mph with the rest of the herd not long afterwards - or you're cheetah-food. Since half of all baby thomsons die that way, the evolutionary pressure to be able to walk (and indeed run faster than my 1963 Mini!) is pretty much up there with learning to fly. At least birds get the chance to get their eyesight sorted out - learn who their mommy is, get some food in them, flap about a bit in the nest to get a feel for how the air feels in their feathers, watch how other birds fly. The gazelle gets one chance and one chance only - and it's priority #1 immediately it's born. Baby whales have to swim the moment they are born so they can get to the surface to take their first breath - if they don't learn - they drown for sure! Baby birds often survive that first fall from the tree when they mess up flying. SteveBaker 16:05, 2 September 2007 (UTC)

Fair points there, Steve. Consider me proven wrong. :) WRT to the baby whales - don't their mothers nudge them to the surface after birth to catch their first breaths? --Kurt Shaped Box 05:27, 3 September 2007 (UTC)

Difference between a transactivator and an transcription factor?

What's the difference between a transactivator and an (upregulating) transcription factor? --Seans Potato Business 18:28, 1 September 2007 (UTC)

See the basic definitions at Transactivation and transcription factor. The basic difference is that a transcription factor usually descibes an endogenous protein whereas a transactivator is a term that can mean anything that activates genes in trans, including upregulating transcription factors that are both endogenous and exogenous (such as viral in origin). Rockpocket 19:36, 1 September 2007 (UTC)

Rockhounding

I am new to rockhounding and recently asked someone to identify some rocks for me. He identified one and I wrote down the name as I heard him say it. Then he corrected me saying that "It begins with a p." I wrote down psyomaline or phyomaline. Two questions: 1. Do you know the rock or how can I find out waht the ending of the word means so I can look up other words with that "maline" ending and maybe gain a little insite. 2. The object was black, felt metalic, relativly flat, shiny on top with small bumps, bottom was probably lying in contact with some other object when it was formed as the bottom is totally different from the top. It is relatively smooth. Do you know what kind of mineral it is? Can you be of any help with either question? Thanks, Bill Rockhounder 18:35, 1 September 2007 (UTC)

ok think I've got it - here's what I did..

First I scratched my head and tried somethings that didn't work..

Then I searched for "minerals list" eg http://ww.google.co.uk/search?q=minerals+list&hl=en

from that I got a list of minerals beginning with p eg http://www.galleries.com/minerals/byname.htm#P

From that I found "PSILOMELANE" which I'm almost certain is your mineral..

This mineral is a transition metal oxide - for similar minerals you could look up 'oxide mineral' - similar minerals might be pyrolusite haematite.83.100.249.228 20:36, 1 September 2007 (UTC)

Was is the right name??83.100.249.228 20:36, 1 September 2007 (UTC)

We have a page on it - see Psilomelane also check the links or do an image search for 'psilomelan' as it can take different forms which don't all look exactly the same.83.100.249.228 20:37, 1 September 2007 (UTC)

By the way 'psilo' means bald as in no hair, or naked, or smooth - because one form looks like a bald head. 'melane' means black/dark as in 'melanin' the skin pigment - this picture will explain why...http://www.mineralatlas.com/mineral%20photos/R/romanechitecp.htm (scroll down 4), however this form http://www.mindat.org/photo-73188.html shows it doing the total opposite - those hairs are the mineral as well, as is the base in this example.83.100.249.228 20:58, 1 September 2007 (UTC) Note these are special examples - mostly it will look a lot more 'normal' for a rock.83.100.249.228 21:00, 1 September 2007 (UTC)

horsepower

My understanding is that one horsepower is determined by the speed at which an average horse can lift a specified load to a certain height. Is it possible that the same horse can exceed this value when running at a full gallop and carrying a heavier load such that the value determined for each situation is different, producing an error if the value determined for one is applied to the other? Clem 19:45, 1 September 2007 (UTC)

The value of 1hp is defined as an absolute value unrelated to what horses can actually do.

However the value of 1hp is roughly equal to the amount of work a horse can do.

See Horsepower#Current_Definitions and the article in general.83.100.249.228 20:24, 1 September 2007 (UTC)

So unfortunately the capabilities of a horse nowadays under standard or other conditions isn't even related to the figure of power that is described by 1hp.83.100.249.228 20:26, 1 September 2007 (UTC)

Ack, and apparently Candlepower isn't related to actual candles anymore either.. Pfly 01:44, 2 September 2007 (UTC)

Which is good because not all candles and not all horses are created equal. We're lucky we can specify these things more precisely. ←Ben^B4 02:09, 2 September 2007 (UTC)

Most of our systems of measurement come about through similar approximations. Even fairly recent ones like the meter have changed several times over the years. The meter started out as one millionth of the distance from the equator to the north pole...but that wasn't very convenient - so they made a chunk of metal to the exact length they thought represented that distance and kept it very carefully in a vault someplace. However, they were wrong in their measurement of the earth - because they didn't realise that it was not a perfect sphere. So the new metal meter was not one millionth of the distance from the equator to the pole - but it was still the legal definition of what a meter is. Subsequently, we've realised that the exact length of this bar depends on too many other things like how it is supported, what the air pressure is and where precisely you measure the rod if the ends are not perfectly perpendicular to it's long axis...and all sorts of other annoying things. So we redefined the meter as some number of wavelengths of the light produced by some particular substance under some special conditions...but that's a messy description because it depends on too many other things - if you specify the exact temperature at which the object emits this light then the meter ends up depending on the definition of the Kelvin - which in turn is defined by the boiling of water under one atmosphere of pressure - which is some number of kilograms per cubic meter...which means that you don't know how long a meter is until you know how long a meter is! The modern definition is the distance travelled by light in a vacuum in some accurately specified fraction of a second - but sadly, the second also depends on the kelvin - so we aren't much better off! A similar thing happened to the horsepower. The idea that this was the amount of work one horse could do was kinda useful as a rule of thumb when selling steam engines to replace horses! But which horse? Which way of extracting work from it? It was all a bit of a pain. So we define it in terms of other units like the foot and the pound...both of which used to be defined by chunks of metal buried in vaults - but which are nowadays defined in terms of the meter and the kilogram respectively. SteveBaker 15:39, 2 September 2007 (UTC)

Is the kilogram the only unit still defined by an artifact? —Tamfang 21:03, 2 September 2007 (UTC)

Yes. The kilogram is defined by an actual lump of platinum-iridium stored in a vault in Sèvres, France. SteveBaker 21:20, 2 September 2007 (UTC)

Discussing Evolution with a Friend...

I've been chatting with a friend about evolution; he is somewhat in disagreement with it. However, he's come up with an objection that I can't really come up with a way to phrase a counter-argument to, so I'm coming here for help.

He says that, even if variation could develop from evolution, any group of organisms in the same environment (humans, dogs and deer were the e‌xamples he used) would develop into the same organism; that best suited to its environment. Because this is not the observable case, he says, evolution is wrong.

I think that his definition of environment is wrong somehow, and that it doesn't incorporate the idea of an environmental niche for a particular species, but I don't really know how to phrase that idea very effectively.

Any thoughts?

Thanks, Daniel (‽) 21:18, 1 September 2007 (UTC)

Well you could say that plants are best suited for an earth enviroment (as an example) - but no plant is perfect - there will always be space for a smaller plant that can live in partial shade - so your counter argument of enviromental niches is a good one - and those niches that can cause the diversity we see - for example very small plants and animals and very big ones..Following on you could evolve one species that can eat all the food available but that means that any plant that can render itself inedible will prosper - producing diversity...83.100.249.228 21:42, 1 September 2007 (UTC)

If I read the statement correctly, your friend is proposing that all species will evolve in parallel into a single "best" species. The problem, I believe, is your friend's apparently naive definition of "best suited." Evolution can be summed up in two very simple concepts: 1) Evolution builds on and alters that which already exists (on the molecular level. New genes don't pop out of nowhere, for example, they just get modified, which can produce new genes only over long time spans); 2) Evolution acts to improve an organisms's chance of having successful offspring. The first is merely the nature of how quickly anything can change, and the latter is sort of proven in reverse; those organisms who are more likely to have successful offspring become more representative of their species over time. Thus, given a group of organisms sharing some environment, they will only evolve in directions that improve their chance of having successful offspring (this also means improving their own chance of survival, for having offspring generally requires that they be alive). So now, I ask you, if the "goal" of evolution is for organisms to make more babies, better babies, make them faster...why would a bunch of different species go on the long and difficult evolutionary path towards becoming the same species? The mutations necessary to do that are incredibly less likely to occur than simpler mutations to accomplish the goals I just gave you. The "niche" part of all this is simply that many organisms can independently be the "best" organism in the environment, the best at surviving in some slightly unique manner. Someguy1221 21:44, 1 September 2007 (UTC)

(edit conflict) There isn't a single "best" fit for an environment. Take a look at the animals of Africa. Some of them are best served by eating grasslands. Some are best served by hunting. Of those, some are best served by going fast, some are best served by working in packs. All of these are "fit" adaptations, but none of them is the "most fit" approach to survival as a species. When multiple species exist and independentally evolve, they also end up shaping the entire set of species. Thus as the predators get faster, the prey get faster (or develop better defenses, or whatever), and vice versa. At some point an equilibrium of sorts falls into place, so that the prey do not become overly depleted and the predators do not run out of food.

Additionally the "environment" is not a static thing — it also include the other species within the environment. So for the humans, the deer and the dogs are part of the environment; for the dogs, the deer and the humans are part of it. The environment itself is in a state of flux.

(Additionally, dogs have been largely artificially bred by humans, and are a bad case study for evolution in almost any circumstance.) --24.147.86.187 21:47, 1 September 2007 (UTC)

On the other hand, you could say "Oh, that's correct; and given a few more billion years, all life everywhere will evolve to pretty much the same state, along with everything else. See entropy death." --jpgordon^∇∆∇∆ 21:52, 1 September 2007 (UTC)

Interesting answer. A.Z. 20:00, 2 September 2007 (UTC)

(edit conflict) It's also important to note that as a species spreads out into new environments, it might find that its own particular niche is not the same anymore (or alternatively, its existing enviroment can change). This might prompt an immediate alteration in which traits are more or less beneficial to the organism, and can result in evolution given enough time. This is simply an example of how not only can several "bests" exist, but what is best changes over time and location. Someguy1221 21:55, 1 September 2007 (UTC)

Actually, the entropy bit is interesting. Imagine modeling all DNA in the world as a thermodynamic system. It changes randomly, but there will be some preference for DNA of a particular sequence to change in a particular manner. Now, to say that all organisms will eventually evolve into the same organism is asking all the DNA in this model to randomly change until they are all very similar. For this to happen would require some incredible preference, some incredible force directing all DNA, regardless of its current sequence, towards one particular sequence. Because of the existence of niches, and the subsequent lack of a single "best" set of traits, there is no such force, and asking this to happen would be like asking the entropy of a system to kindly go down. Someguy1221 21:59, 1 September 2007 (UTC)

Your friend's argument doesn't hold for much. He thinks that evolution says that if the environment is the same for all the organisms in it, the organisms would turn into the same species; he has a very poor understanding of evolution. First of all, since the organisms in the environment are different in the first place, it makes it impossible for them to evolve into the "same species" in the future. Selection pressures in evolution works on what organisms already there; the same evolutionary forces may be at work, but since the base organisms are all different, the variations produced will be different.

For example, let's say the environment is the savanna filled with cheetahs. And let's say that the sole selection pressure (what will make some species thrive and others fail) is how fast a species can go (in order to avoid fast predators. In this simplification, faster gazelles would evolve, faster elephants, giraffes, etc. would evolve. Faster organisms will evolve, but they don't become "one" species, or the same organism.199.76.186.8 22:13, 1 September 2007 (UTC)

Oh, let me add that one of the most amazing observations of evolution is convergent evolution. This is where relatively unrelated species living in a similar environment and pressure would develop similar features. Take whales, which are of course mammals, fish, and ancient marine reptiles such as Ichthyosaur. They all evolved similar features (streamlined bodies, fins placed in similar places, etc.) because they lived in the same environment (water). Note that there are still subtle differences. The tail fin of whales, on one hand, are horizontal, while fishes are vertical. This is a case where two different solutions work for a problem. So in this sense, different organisms do evolve to similar organisms. But your friend's demand that the animals have to evolve to the same exact species is unrealistic.199.76.186.8 22:20, 1 September 2007 (UTC)

Convergent evolution can be pretty amazing. The main examples that come to mind are the way lemurs came to dominate Madgascar's ecological niches that elsewhere were long controlled by other species (at least until human-introduced species and logging, etc, put the lemur-ecosystems under much stress). Another example is marsupial dominance of Australia's ecosystems. In some cases, as I understand it, the outward appearance of one species may have come to closely resemble that of another, quite unrelated species -- but that due to the very different origins (lemurs vs. marsupials, vs who knows what else) there remain many important differences beyond a cursory outward appearance. The same idea holds for flora -- Australia's tree species are, as I understand it, dominated by Eucalyptus and a few other types. A shrubby "weed tree" around the time of Australia's isolation, the Eucalyptus adapted to a very wide range of niches, spawning a large number of distinct species in the process. As for eventually merging into a single species, this would seem to require something like interbreeding arises between, say, kangaroos and elk, which seems a long shot. Pfly 02:58, 2 September 2007 (UTC)

There's a South American rodent that looks like a little deer (about as big as a housecat). I would guess that its native region has no real deer. —Tamfang 21:00, 2 September 2007 (UTC)

One more consideration is that the environment isn't just an empty landscape with static obstacles for an organism to overcome in its quest to survive and reproduce. The environment is filled with other organisms. If all the organisms evolved towards the same ideal, there would be intense competition for the resources. Imagine if every animal in Africa started trying to eat grass. Grass would be hard to come by, but if some species, instead of eating grass, learned to eat fruit or leaves (or even other animals - predation is a hugely successful strategy), they would have all the food they could handle, since there would be no competition. This is what evolutionary niches are. Evolution pushes organisms in two directions - the first is to be more competitive in your present niche, and the second is the find new niches where there will be less competition. If all the organisms started competing for the same resources, any organisms that found -other- survival techniques would be onto a winner. Maelin (Talk | Contribs) 02:12, 2 September 2007 (UTC)

Another very interesting concept to keep in mind is disruptive selection. This is the case in which two opposing traits are favorable to possess, but anything inbetween is not. Examples are species of Finch in the Galapagos. Some of these species have access to two primary sources of food, both nuts, large and small. Each type of nut can only be easily broken by a particular sized beek, large or small. Medium sized beaks are greatly inferior at opening nuts, and such finches will be deftly outcompeted by those finches that possess the "extreme" sizes. Someguy1221 03:08, 2 September 2007 (UTC)

I think there are a few good reasons. Evolution most often comes about because of a change of environment. Consider an uninhabited island - onto which animals are swept by clinging to vegetation or something. Two species of animal - one evolved from a hotter drier climate than our island and the other evolved on a cooler, wetter environment are washed onto the island. In order to better adapt to it's new conditions, each has to evolve some. If the animal that came from the cold, wet place has white fur and dark skin with thick subcutaneous fat deposits (like a polar bear), the other creature may have dark fur and a light coloured skin with little stored fat (like a brown bear maybe). Now, will both species evolve into the exact same creature? Probably not - the white animal may be able to adapt to be perfectly at home in the new warmer location by simply shedding some of it's fur. The dark-furred animal may need to grow slightly more fur to keep its lean body warm in this cooler environment. Both changes would require only small genetic modification - and yet we now have two different solutions to keeping the animal at the right temperature. For the two creatures to turn out to be identical, each would have to change fur colour, skin colour and fat-retention strategies - and that's a much bigger change than a simple change to fur density. So you end up with two quite different animals - both at home in the new climate - one bald and dark-skinned, the other hairy and white-skinned - both perfects well adapted.

Another reason is that there might be more than one possible food source on the island which might split a single species into two. So if the island has nuts lying around everywhere and also ample small fish in the rivers, a species of fruit-eating bird coming to the island might be poorly adapted to either diet. One individual might get a random genetic mutation that strengthened it's beak to the point where it could thrive by cracking open the hardest nuts that the other birds couldn't eat - where another individual might randomly develop a long, thin beak to efficiently spear the more agile of the fish (although in the process become less good at eating nuts). At this point, subsequent generations of birds will adapt to the diet they have chosen and sooner or later, you have two totally different species of bird living in the exact same habitat.

If you toss in a small number of initial species and provide a number of different food supplies, then before you know it, you have diversity. You could imagine other kinds of diversity-causeing differences - but this is enough to knock your friend's argument out of the ballpark. SteveBaker 15:19, 2 September 2007 (UTC)

Wow. Thank a lot, all of you. I gave up on summarizing this and send the friend to read the whole thing himself. So far I think he's impressed. Daniel (‽) 19:17, 2 September 2007 (UTC)

Hi, I am the friend to whom Daniel is referring and I thought I'd just like to clarify some of my thoughts on the subject.

My point was that all organsms originated from the same place and then, presumably spread out at some stage to different environments where the "evolutionary mechanism" caused various changes to their makeup. However, there are a limited number of inhabitable environments on the planet each with their own (presumably) unique characteristics and so in each area, one form of the organism would prove most able to survive and, over time, emerge as the predominant species.

One cannot object to this by imagining a situation in which several different animals are present without explaining how they came to exist there in the first place!

It seems plausible to me that different species could live harmoniously as above users have asserted. However, I don't feel this accounts for rather large differences in makeup of species which live in the same environment. To put it bluntly: wouldn't every animal develop desirable characteristics such as the comparitively extrodinary brainpower that humans posess?

Another objection I raised was how complex organs such as the eye and aspects of the circulatory system evolved, as it seems to me that randomly occuring mutations "half a heart" or "half an eye" would be of no use at all without other components in te organism!

Thank you for all of your comments and please correct my ignorance as you see fit (I am as you may gather by no means an expert with regards to evolution). —Preceding unsigned comment added by 86.112.251.136 (talk) 19:43, 2 September 2007 (UTC)

Brainpower is not an absolute good; it requires extra energy and growth for the brain, and in humans it has required the shape of a woman's hips to change so that the larger head can emerge, making a woman's hips slightly less well-adapted for other things. What would a worm do with extra brainpower?

As to the last objection, remember that the randomly occuring mutations are each generally very small. So you wouldn't randomly be born with half an eye, you might randomly be born with a few light-sensitive cells which allow you to gauge light and shadow. The evolution of the eye is quite studied, so I'll leave the article to explain further! Skittle 20:08, 2 September 2007 (UTC)

And as for "half a heart" – if I remember right we still have partial hearts, in that our arteries have muscles that participate actively in pushing the blood along (veins are passive). The first proto-heart may have been a specialized node in a system of previously unorganized arteries. (Likely it allowed its owner's descendants to grow to unprecedented sizes, and thus claim empty niches.) I don't know of any animals with one- or two-chamber hearts, but don't some reptiles have three-chamber hearts? —Tamfang 21:00, 2 September 2007 (UTC)

Yep - the 'what use is half an eye' argument is a classic creationist ploy - but it's only hard to understand if you don't bother to read the scientific explanation - which is quite clear and logical. Creationists don't read the science because they don't particularly want to understand it. Evolution of the eye is a great explanation. It doesn't take much imagination to come up with a similar scenario for development of hearts, ears, brains and any other organ you could come up with. But religion doesn't encourage imagination...with predictable results.

But coming back to the "how does diversity come about" issue - OK, I buy that life started in one place, probably in the oceans and with just one 'organism'. It's clear though that there are other environments than just the ocean. So as competition for resources in the ocean grows, there is an evolutionary pressure to change in order to colonise these other environments. So it shouldn't be hard to understand why there was initially enough diversity to provide at least one species per habitat. But as I explained in my 'island' analogy above, a single species in a single environment may well split into two species - each utilising a different resource within that environment. That's how come the same island has birds that are specialised to eat fish, birds that are specialised for fruit, birds who eat insects and birds that eat seeds. Each one needs some kind of specialism to be best at what it does - that also makes it worst at one of the other specialisms. So that lets us have multiple species in one environment - each one exploiting a different resource. Now apply the argument I made about the two kinds of bears who evolved for different environments who meet to exploit a single resource in a single environment. Each has to evolve to suit that new environment - but they may find it easiest to evolve in different ways. So it should come as no surprise that when (say) the African plains have a lot of animal carcasses lying around, both dogs and birds come in to exploit that resource - and you end up with Hyenas and Vultures who are both finely evolved to exploit that resource - but which (because of the evolutionary paths they used to get here) wind up looking totally differently. This just doesn't seem like much of a difficult puzzle to me. It's obvious.

SteveBaker 21:08, 2 September 2007 (UTC)

If I may just register my objection to the declaration "...religion doesn't encourage imagination..."? Completely off the point, inaccurate, unsupported and a great way of reducing an interesting scientific discussion to 'They say, We say', alienating people rather than informing. This is not about religion vs science, it is about understanding a scientific theory. That some people co-opt these things for their versions of a particular religion does not change this. A little less dogmatism would be nice. Skittle 23:20, 2 September 2007 (UTC)

On this idea: there are a limited number of inhabitable environments on the planet each with their own (presumably) unique characteristics and so in each area, one form of the organism would prove most able to survive and, over time, emerge as the predominant species. I'd suggest that yes, where there is intense competition between multiple species for the same exact ecological niche one of the other will ultimately win, with the other going extinct. On the other hand, if one or the other competitors develops a slightly different strategy or "way of life", then in effect they are no longer competing for the exact same niche. Since different species naturally have different "ways of life", I might argue that you never find different species competing for the exact same ecological niche. Each brings unique strengths and weaknesses that alter the playing field, so to speak. Then there is the matter of geography and how space separates species, allowing different species to dominate the same "niche" in different places because the competitors are simply not there. In this sense, there is an important difference between "form" and "species", which is essentially what the idea of convergent evolution addresses. The first example I could quickly find was the Marsupial mole and the "regular" mole. There are numerous similar examples. The point is that similar environments (like, say, the environment of burrowing mammals) will naturally favor certain "forms" (strong digging hands, poor eyesight, good smell, etc), but this doesn't not necessarily mean that marsupial moles and "regular" moles are remotely similar, species-wise, even if they take similar forms. The two forms of "moles" (and there are far more than two such forms) can exist simultaneously because they are geographically isolated. If all critters were given equal access to the entire planet, then we may well see a large number competing for the same environmental niches. No doubt many would go extinct. These days, with humans transporting animals all over the place, something like this may well come to pass. Pfly 06:42, 3 September 2007 (UTC)

Thank you for your comments.

Perhaps due to my own scientific ineptitude, I cannot see many problems with the aforementioned "Evolution of the Eye" theory; however it is apparent that some evolutionary steps (such as the development of the faculty for vision in colour) are too big to have arisen through genetic mutation. Similarly, the harmony with which the human circulatory or nervous system seems to operate suggests to me that it could not have developed through evolution. Different organs bound together through the bloodstream in such a fashion seems to be an example of irreductible complexity as the function of each organ could not be acheived independently of other connected organs. Even if this were the case, the sudden introduction of a link like the blood is too large a step to have occured through genetic mutation.

Whilst I concede that it is certainly possible for different animals and plants to exist harmoniously when competing for different niches in different conditions, I cannot understand how they could co-exist when competing for similar resources. In the example mentioned above, where both a small beak and a large beak are suitable for opening something, it is impossible that both features are exactly equal in effectiveness. One adaptation must be more herlpful than the other, thus rendering, over time, the species with that feature the predominant one and forcing the other into extinction.

Conor Husbands (Daniel's friend) —Preceding unsigned comment added by 86.139.145.169 (talk) 12:21, 3 September 2007 (UTC)

It is not because of your scientific ineptitude that you cannot see many problems with the eye evolving as generally accepted by the scientific community. Quite the opposite; it is because you can see it makes sense and is supported by evidence. Again, you are thinking in very big steps, while each mutation produces only a very small step. There wouldn't be a single 'colour vision' mutation, there'd be the ability to detect one particular colour seperately from the others. For example, the ability to see how red something is, enabling you to better judge the ripeness of fruit from a distance (I am speculating here). This would most likely occur in very small steps, just as everything else does. Once you have one colour receptor, mutations are possibly to detect other colours.

As for irreducible complexity, I advice a read of the article I linked. The concept depends on thinking that evolution only acts on one thing at a time, and always drives towards one goal. In the theory of evolution as developed based on observations and theorising by biologists, things can evolve originally for one use, then change that use as other things change. Things can evolve side-by-side as well. For example, a plant might originally pollinate through the wind blowing the pollen and some of it reaching the stigmas of plants of the same species. At the same time there might be an insect that feeds on sweet things such as juice from fallen fruit. If there is some small mutation in one of the plant's descendants that makes it smell sweet, or produce a small amount of sweet liquid, near where it keeps its pollen, the insect will be drawn to the sweet liquid and incidentally get pollen on itself. If it then flies to other similar plants, it will carry more pollen than the wind would have carried. With other tiny steps from here, you have the interconnected relationship of bees and flowers.

As for the bloodstream, I hope the article on circulatory system is informative, but my battery is too low to check. But there are small creatures that have 'blood' and some basic organs, but no circulatory system. Things like a circulatory system, a heart, lungs, etc only become useful when you grow too big for diffusion to take care of things for you, and can develop gradually in steps of increasing usefulness.

With the beaks and the birds, why would either species go extinct just because the other is more successful, when differentiating has ensured they are in different niches. Both populations evolved from a single species that came to the island, some of the descendants evolved to have larger beaks (in small steps, each mutation producing only a small increase in size), some evolved to have smaller beaks. The birds with larger beaks can now eat one type of food, the birds with smaller beaks can now eat a different type of food. Both species have evolved to fit their ecological niche, but they are in different niches even though they are on the same island and are descended from the same species that arrived on the island at the same time. Any clearer? Skittle 22:37, 3 September 2007 (UTC)

And it's not just food supplies within one environment either. You might find a pair of animals that live in the same place and who both eat (say) insects - but one evolves to hunt at nights while the other hunts during the day - or one hibernates through the winter and hunts only in the summer while the other is more cold-adapted and hunts in the winter and migrates to cooler climates during the summer - or one hunts down at ground level whilst another specialises in working the treetops. Each could evolve for it's particular life-style without having to directly compete with the others. There are all sorts of differentiator that can provide a new niche to allow multiple species to inhabit the same environment without one of them completely out-evolving the other. It might indeed be rare to find two species living in the same area who both eat the same insects, hunt at the same time of day and year and both in the same parts of the ecosystem - one of those would be expected to out-evolve the other and drive it either to extinction - or to evolve to either work a different food supply or to use the same food supply in a way that the dominant species cannot. SteveBaker 15:01, 4 September 2007 (UTC)

What I will say could have possibly been said by previous posters. You say that eyes and hearts can't evolve because "half eyes" and "half hearts" can't fully function together; this is mistaken because it is possible for "half organs" to function. If you look at "simpler" animals, (for example, worms or the Amphioxus) you can see how their primitive organs work. In the Amphioxus, for example, there's no complete heart; what they have is a short section of a blood vessel that's slightly more muscular. Millions of years ago, a primitive heart like that would have evolved to a more robust heart. Amphioxus is still living today, despite their simple forms and a lack of organs we deem crucial for our body, such as kidneys, lungs, and the liver. So, if you observe simpler organs in other animals, you can understand how it was possible for the complex systems to evolve from simpler forms.128.163.160.121 22:49, 6 September 2007 (UTC)

• Perhaps your friend also wonders why the United States Navy operates both aircraft carriers and Zodiac inflatable boats, when clearly their designs for the marine environment should evolve to a super-boat that can both launch F-15s with a steam catapult, and also be deflated for easy stowage? --Sean 16:08, 4 September 2007 (UTC)

Perhaps you ought to realise that live organisms are capable of independent evolutionary change whereas mechanical devices cannot, thus rendering your facetious remark invalid.

Everything we have today has evolved. Computers started out as abaci as far back as 2400 BC. They have very slowly evolved to what we have today. Buildings, crops, cars, lighting, none of these things just appeared as they are today. They evolved over many years some over many centuries. It's not that difficult to see how life could evolve as well. As far as the eye or the circulatory system being so complicated and precise that it must have been created, there are many more things in life that are redundant or clumsy, for instance, the digestive systems of many animals are repetitive or not very efficient. As for dominant species in an environment and how species can co-exist, some can't. Species are becoming extinct all the time because of deforestation, etc so not all species co-exist. --Beckerj99 21:14, 4 September 2007 (UTC)

It seems like the (original) questioner should be directed to our articles on evolution and natural selection, first. Additionally, one might benefit from reading about ecological niches and their importance in biological fitness. It would also be wise to peruse argument from personal incredulity as that seems to be the main logical fallacy at work here (that you can't imagine how something occurs is not evidence against such an occurance)--this is not to be taken personally, as it's quite wise to familiarize one's self with logical fallacies in order to avoid making them. Hopefully the thought experiment I've written below will clarify the mechanisms involved.

To address a couple of conceptual problems I see...consider a game of chess or checkers. There are literally millions of move combinations that can lead to "victory" with no combination objectively better than the other (because the result is all that matters). If one considers the devlopment of speciation as a game of chess: the first move goes to the opponent (the environment of a population of organisms). The choices of a response move vary in their strength, measured as the liklihood of a win based on the current board positions. As the game progresses, the environment's moves contain an element of randomness (just like real life) that has an integral effect on the liklihood of any strategy's ultimate success. In the end, a relatively simple game like chess is estimated to have approximately 10¹²³ possible game trees; one can be sure that the natural environment has far more variables up its sleeve than a medieval board game, but the vision of the game may prove useful to imagining natural selective processes.

To take the chess analogy further...When one plays such a game, it's against the rules to take a move back. This is the same in evolution: future events are constrained by past events--if your queen is captured, you can't have it back (ignoring, of course, a promoted pawn) and that will dictate what strategies & moves are available in the future. Similarly, if a genetic change duplicates, inactivates, or alters the function of a genetic product, that change will be inherited in any offspring and said offspring would have to have the very improbably exact reveral of such a mutation to be back at square one. Evolution builds upon these changes, selective pressure imperfectly weeding out the least "successful". This imperfection is

Finally, to stretch this analogy even more...if one were to imagine 100 different simultaneous chess games, the environment on one side and 100 offspring of an ancestral organism on the other. The environment plays the exact sequence of moves in each game, as do the organisms, except they vary by one move in their opening strategy (as they might have variability in genetic information and ultimately selectable phenotype). Likely many games will end with a different pattern of pieces on the board, and likely some organisms will lose. The losers may come disproportionately from a certain move type, indicating that such a strategy is not condusive to "survival". One step beyond this: the previous round's winners asexually spawn offspring that play their progenitor's exact same sequence except for another possible random change. Subsequent iterations would potentially produce a wide variety of similarly successful, but rather dispirate stategic combinations--equivalent to adaptation to different niches--that are objectively no better than the other (as the win, or the successful replication and spread of genetic data, is all that ultimately matters). This sort of mindplay is foundational in the really cool science of game theory which has added a lot of great knowledge to the modern evolutionary synthesis, especially in regard to models of population genetics. — Scientizzle 22:27, 4 September 2007 (UTC)

Why do 'flammable' and 'inflammable' mean the same thing?

...and why are both terms still in use interchangably? Isn't this really dangerous? I've heard of people being killed after thinking that inflammable meant 'not flammable'. —Preceding unsigned comment added by 84.68.243.102 (talk) 22:36, 1 September 2007 (UTC)

Inflammable comes from the word "inflame" which means "to burst into flame." Flammable, obviously, comes from flame. It's merely curious in that "in" can mean "not" as a prefix. Someguy1221 22:45, 1 September 2007 (UTC)

No one said the English language made sense! -- 68.156.149.62 02:02, 2 September 2007 (UTC)

The correct antonym for "inflammable" and "flammable" is "non-flammable". Maelin (Talk | Contribs) 02:04, 2 September 2007 (UTC)

Why don't you suggest this to IUPAC or whomever you think is the most suitable authority regarding to this matter? You may become famous;) --Mayfare 03:16, 2 September 2007 (UTC)

Given that most authorities already recommend against use of the word inflammable for that very reason it's somewhat unlikely Nil Einne 15:20, 2 September 2007 (UTC)

I placed a winking face for a reason. --Mayfare 22:40, 2 September 2007 (UTC)

Of the two synonyms "flammable" and "inflammable", at one time only "inflammable" was widely used. In the 20th century people involved with fire insurance promoted the use of "flammable" (and similarly, "non-flammable" rather than "non-inflammable") precisely because "inflammable" could be misinterpreted. While there is apparently no hard evidence to confirm it, the timing and circumstances are right for Benjamin Whorf to have been the man behind this. --Anonymous, 11:58 UTC, September 2, 2007.

The short answer is that they mean the same thing. The world is trying hard to forget that the word 'inflammable' exists - preferring to use 'flammable' and it's antonym 'non-flammable'. However, I was always taught (UK English) that the two words didn't mean precisely the same thing - they were not opposites - but did have subtly different meanings. Inflammable comes from a Latin word: "inflammare" meaning "to kindle". Flammable comes from a different Latin word, "flammare," meaning "to set on fire". As I was taught, an inflammable substance was capable of spontaneously bursting into flames where as an flammable substance would burn if you set light to it - but would not spontaneously catch fire. I don't think many people make that distinction nowadays - and as a society, we should probably simply try to forget that 'inflammable' exists as a word and use 'flammable' for both cases. SteveBaker 14:53, 2 September 2007 (UTC)

(I just though of another pair of words like that: Imprint and print also mean the same thing - unlike impossible and possible!) SteveBaker 14:56, 2 September 2007 (UTC)

Moreover, that is why English have two different words. No two different words have the exact same definition. Otherwise, why would English have those two different words that mean the same thing? It would be redundant, adding pages to dictionaries, thesauruses, and so on and so forth. (A little bit off the topic - That is also why word choice is so important!) --Mayfare 16:52, 2 September 2007 (UTC)

Latin has two prefixes in- and īn-, normally written alike. The first, with a short vowel, comes from the ordinary preposition in; in some Romance languages it becomes en-. The second, with a long vowel, is cognate to English un-. The word inflammable has the first prefix; compare enflame. HTH. —Tamfang 20:44, 2 September 2007 (UTC)

and why do you drive on the parkway and park in the driveway? Gzuckier 15:21, 4 September 2007 (UTC)

One catches a train at a parkway. DuncanHill 15:25, 4 September 2007 (UTC)

Advice for the kids, when confronted by this (or a similar) situation. Just because you believe, based on what it says on the label, that something is not going to burn - it doesn't mean that you necessarily *have* to try setting it on fire. --Kurt Shaped Box 17:06, 4 September 2007 (UTC)