Mokele

Quite often in non-technical sources, you find people talking about 'poisonous snakes', often referring to species such as cobras or rattlesnakes. And the usual smart-aleck response is "There's no such thing as a poisonous snake, only venomous snakes", the difference being that venom is a method of procuring prey (as in cobras and such) or fighting off predators (wasp venom), while poison usually refers to a chemical that must be consumed to have an effect. Paper on poisonous garter snakes In the pacific northwest, there's a small, harmless snake (the garter snake) with a wide ranging diet. One particular population preys mostly upon newts, the catch being that these newts contain tetrodotoxin (apparently aquired from bacteria; the same chemical is the toxin in pufferfish). As a result of their prey's super-potent nerve toxin, the snakes have evolutionarily modified the sodium channels in their nerves to be less responsive to that toxin (which has had secondary effects of decreasing nerve performance). Of course, this set up an evolutionary arms race, with more toxic newts evolving, which lead to more resistant snakes, which lead to more toxic newts, etc. However, tetrodoxin takes a while to break down. The paper above shows that it disappears fairly fast from most of the snake's tissues, except for their livers, which it accumulates in large quantities for long periods of time. This has the potential effect of making these snakes toxic to many of their native predators, especially birds. Other species do this too (dart frogs actually get their poison from ants and beetles), so it's technically truly a poisonous snake. So yeah, there you have it, a poisonous snake. Mokele

Well, then we wouldn't get scurvy. This could be the end of piracy as we know it!

I love the false dichotomies. Either it was warm-blooded or it wasn't, ingoring the fact that monotremes and marsupials do not have full control over their body temperatures, which it turn proves the intermediates can exist. If it had a growth method like a reptile, it must have had a reptilian metabolism. Never mind that extant reptiles have a wide range of metabolisms and all show this growth method, and that nothing *specificially* links this sort of growth to ecotthermy. It's interesting, but I think everyone leaps to conclusions too quickly about these sorts of things. I strongly suspect the metabolic diversity actually present in dinosaurs would shock even the most imaginative paleobiologist. Mokele

Ok, I figured this is the best place for an attempt to get some action. There are plans afoot in Aus. to build dams on the Mary and Burnett rivers. The problem is that these two rivers are the *only* habitat of Neocerotadus forsteri, the Australian lungfish. This huge and scientifically invaluable species is *not* good at dealing with disruptions to its nesting, and these dams may wipe them out. This species is also unique even among lungfish: the african and south american species only have thin, tendril-like fins, while this species has large, fleshy lobe fins, like are seen in fossil lobe-fins. A post on a science blog detailing the creature's plight A second post in the same blog, giving email addresses of the relevant politicians Please, please take the time to send a polite email to these people telling them that they are about to snuff out one of the most unique species on the planet. Mokele

I'm right there with you, DrCould, as is everyone who's knowledgable in their subject and has invested much of their lives becoming so. The ugly fact is that people don't like being corrected, especially publically. However, that should not deter us; the purpose of this forum is, among many, to educate, and that means esnuring that information posted is accurate. That information here is scrutinized and corrected by many knowledgable eyes is one of this site's greatest strengths. As far as pissing people off, I'm *definitely* the wrong person to ask on that. On basically every board I've been on, I've been known for my willingness to publically show people they're wrong, usually with as much tact as a nuclear strike. On one hand, I've pissed lots of people off, on the other, if they get pissed at being corrected on matters of fact, I don't care what they think anyway. I'm probably mangling the quote, but Confucius once said that the sign of true virtue is not pleasing everyone, but being hated by the bad and revered by the good. Mokele

Closed, and I have to say I'm extremely disappointed (and rather irritated) at the direct this thread and the similar one have taken. Mokele

No. I'm closing this pathetic excuse for a thread, and it's bastard cousin. The conduct in this thread has been atrocious, and I had beeter not see any hints of a repeat performance. Mokele

Oh, for the love of Zombie Jesus! Hands up everyone who's ever read any of Raup's work on extinction? Nobody? Good, now sit down and shut up. The persistent stupidity in this thread is about to end. Extinction is not "good" or "bad". Nor is it even survival of the fittest. Lions do not drive antelope into extinction, they just produce an evolutionary arms race. Species go extinct when exposed to something they cannot deal with: changes in habitat, loss of species they depended exclusively on, temperature changes, exceptionaly long famine, exceptionally long drought, shopping malls, invasive species, etc. The point is that animals adapt to their immediate, local environment (biotic and abiotic). When something drastically changes in that environment that pushes the species in ways it has not adapted to, it goes extinct. That's the important part: things it has not adapted to. Species are not "good" or "bad" or "smart evolvers" or "dumb evolvers". Every species evolves to suit it's niche. Extinctions occur when that niche disappears or becomes uninhabitable. Faulting a species for that is like faulting a fish for having gills. Raup has done extensive work on evolution, particularly in relation to extinction in the fossil record. Do you know what he found? The pattern of extinction with respect to phylogeny is RANDOM. In any given time span, we're as likely to lose a mouse species as a crab or worm or fish. Entire lineages die off not because they were 'less fit' but because, by chance, they faced an environmental challenge which they were unable to deal with due to factors present in all of them by shared descent, factors that may well have been adaptive in normal circumstances. Maniraptoran theropods' high metabolism was a bonus that helped them catch prey, but it was a fatal flaw when a big space rock caused a worldwide famine. The effects of extinction are mixed: important lineages can die out, extinguishing ancient and interesting groups, but in doing this they can make way for previously marginalized groups to diversify. Some lose, some win. That's life. No 'good' or 'bad', just change. Where do humans come into this? Well, first, we're no different from anything else in a major way: the arrival of a new species often causes widespread destruction, whether it's an invasive snake or new disease or a very smart ape. However, we're different in a major way: we're the first known species to be able to see on a long term extending into centuries. We can extrapolate our effects. Now, while nothing we do is *innately* good or bad, we, as humans, assign such labels to things, and, of course, different humans have different labeling schemes. Two things we are aware of, though: humans cannot be wanton in our environmental exploitation, or we'll sabotage the very infrastructure that supports us. Many fictional dystopias focus on this possibility, indicating that humans are indeed aware of it, though of course disagree about our path exists. Still, most humans agree that staying alive, at least on a personal level, is good. The other is that other species are useful. This plays into extinction because in many cases, we're just beginning to see how useful some are. Chemicals from rare sponges or plants may help save many lives. Some species might provide useful scientific models in the future as zebrafish and fruitflies do today. Basically, we can't fully asses the value of any species, because we don't know what the future holds. Of course, there's other arguements, about the value of biodiversity and species and such. But that's more apes sticking labels on things and flinging poop at each other when they disagree. The punchlines: 1) extinction is essentially random with respect to fitness 2) extinction can either harm of benefit a species, so 'good' or 'bad' depends on your perspective as a species. 3) while there's lots of disagreement about humanity's effect on the world, we all basically agree that we don't want to die and we want nifty things from nature. 4) everything else is apes slapping labels on things. Done, problem solved. Mokele

Oh, for the love of Zombie Jesus! Hands up everyone who's ever read any of Raup's work on extinction? Nobody? Good, now sit down and shut up. The persistent stupidity in this thread is about to end. Extinction is not "good" or "bad". Nor is it even survival of the fittest. Lions do not drive antelope into extinction, they just produce an evolutionary arms race. Species go extinct when exposed to something they cannot deal with: changes in habitat, loss of species they depended exclusively on, temperature changes, exceptionaly long famine, exceptionally long drought, shopping malls, invasive species, etc. The point is that animals adapt to their immediate, local environment (biotic and abiotic). When something drastically changes in that environment that pushes the species in ways it has not adapted to, it goes extinct. That's the important part: things it has not adapted to. Species are not "good" or "bad" or "smart evolvers" or "dumb evolvers". Every species evolves to suit it's niche. Extinctions occur when that niche disappears or becomes uninhabitable. Faulting a species for that is like faulting a fish for having gills. Raup has done extensive work on evolution, particularly in relation to extinction in the fossil record. Do you know what he found? The pattern of extinction with respect to phylogeny is RANDOM. In any given time span, we're as likely to lose a mouse species as a crab or worm or fish. Entire lineages die off not because they were 'less fit' but because, by chance, they faced an environmental challenge which they were unable to deal with due to factors present in all of them by shared descent, factors that may well have been adaptive in normal circumstances. Maniraptoran theropods' high metabolism was a bonus that helped them catch prey, but it was a fatal flaw when a big space rock caused a worldwide famine. The effects of extinction are mixed: important lineages can die out, extinguishing ancient and interesting groups, but in doing this they can make way for previously marginalized groups to diversify. Some lose, some win. That's life. No 'good' or 'bad', just change. Where do humans come into this? Well, first, we're no different from anything else in a major way: the arrival of a new species often causes widespread destruction, whether it's an invasive snake or new disease or a very smart ape. However, we're different in a major way: we're the first known species to be able to see on a long term extending into centuries. We can extrapolate our effects. Now, while nothing we do is *innately* good or bad, we, as humans, assign such labels to things, and, of course, different humans have different labeling schemes. Two things we are aware of, though: humans cannot be wanton in our environmental exploitation, or we'll sabotage the very infrastructure that supports us. Many fictional dystopias focus on this possibility, indicating that humans are indeed aware of it, though of course disagree about our path exists. Still, most humans agree that staying alive, at least on a personal level, is good. The other is that other species are useful. This plays into extinction because in many cases, we're just beginning to see how useful some are. Chemicals from rare sponges or plants may help save many lives. Some species might provide useful scientific models in the future as zebrafish and fruitflies do today. Basically, we can't fully asses the value of any species, because we don't know what the future holds. Of course, there's other arguements, about the value of biodiversity and species and such. But that's more apes sticking labels on things and flinging poop at each other when they disagree. The punchlines: 1) extinction is essentially random with respect to fitness 2) extinction can either harm of benefit a species, so 'good' or 'bad' depends on your perspective as a species. 3) while there's lots of disagreement about humanity's effect on the world, we all basically agree that we don't want to die and we want nifty things from nature. 4) everything else is apes slapping labels on things. Done, problem solved. Mokele

Well, in all fairness, dinosaurs do still exist today in great numbers (birds), and reptiles do grow continuously throughout their lives (some recent studies indicate that at least prosauropods had this reptilian-style growth). Frankly, though, I wouldn't be surprised is he claimed Apatasaurus shat gold. Mokele

Well, hang on there: alien species do not spread without limit; most hit some sort of climatic or ecological barrier and stop. This particular species has been in the US for a long time, so it's had ample time to fill out its possible home range and reach a stable state. Given that this home range is now expanding again, that means either the animals have found a way to circumvent the barrier, or that the barrier itself has moved. Mokele

Interesting, I never knew the developmental basis for such things. I suspect you're right that gorillas use strategy number 1, as the skulls I've seen all have uniformly colored teeth until the portion in the socket. Mokele

Oh, gods, such profundity on something so simple. There is an external world out there which we interact with. In order to more effectively do so, we have evolved numerous senses which gather information about the external world. Obviously, it is in the best interest of the organism to integrate the aquired data into as accurate an understanding of the world around it as possible (since failure to do so would result in walking off cliffs and the like). Therefore we have evolved a complex neural system which integrates the gathered data to form a reasonably accurate picture of the world around us. Basically, we know what we see is actual size (or close to it) because hundreds of millions of years of evolution have gone into refining our ability to accurately understand the external world via sensory information. Any system that was majorly inaccurate would have had seriously deleterious consequences and been immediately supplanted by a more accurate system. Mokele

Actually, the authors mention examining the effects of prior miscarriages and abortions at the end of the paper. Mokele

Actual lightning strikes have variable effects, as noted earlier. As for fish, I know that in freshwater at least you can capture fish using electricity. Low currents stun them temporarily, high currents permanently damage or kill them. The technique of electrofishing with low currents is often used for non-destructive sampling of river ecosystems. Mokele

Wikipedia has a fairly complete survey of the literature on the topic of the sexual effects of circumcision. The punchline: so far, the studies are inconclusive and contradictory, preventing a strong consensus from being reached. Frankly, I doubt there's any medical reason behind most infant circumcision; it's more social or religious. I just can't imagine Joe Sixpack researching this before the decision. So, if we ignore the medical benefits/harms, what do we have? A surgery being performed on individuals without their consent for social or religious reasons. Mokele

Very possible, though there's obviously a limit to it, else they'd've colonized Canada by now.

Well, firstly, I can easily refute that the lizard has always been there: it's an introduced species, and probably arrived in the US with the advent of increased shipping, so 200 years tops. As to how recent this range expansion is, you're correct that it can be difficult to asses. However, this species is not exactly hard to find; their favorite hunting area is porch lights. The prof in my dept who works with a similar species collects them just by driving around neighborhoods at night and picking them off people's walls. Also, this species breeds extremely rapidly, so they don't exactly stay rare for long after they arrive. While it's difficult to establish the precise time of their arrival, I doubt they could have been around for more than 5 years without being noticed. What puzzles me is how they deal with winter. I know this species from FL and Louisiana (though it's considerably more widespread), but OK winters can't exactly be pleasant, especially for a tropical gecko. Either winters have been warmer (interesting support of global warming) or the lizards have found a physiological or behavioral mechanism allowing them to survive the OK winters (also interesting). Either way, it's interesting. Mokele

You actually got the PRS system to work? Holy shit, how?! We've had it here for years and it *still* doesn't work properly! What I find makes the *most* difference is enthusiasm. A teacher can be a Nobel Laureate, but if it's obvious they don't want to be teaching, or if they've been stuck teaching something only distantly related to their field. No teaching technique in the world short of buying hookers for the whole class will save you if you lack enthusiasm. Mokele

Nothing that could properly be called one, no. Sundews and butterworts have sticky glands all over their leaves, and they just digest anything that lands and sticks. The pitchers of pitcher plants are just modified leaves that secrete enzymes and digest anything that falls in. Flytraps and bladderworts have active traps that mechanically capture the insect, but after that it's the same as a pitcher, with glands inside digesting it. If you're from the US, I recommend http://www.petflytrap.com http://www.californiacarnivores.com or http://www.cobraplant.com for some flytraps. In most places (just about anywhere except the desert) they can be kept outside. I'm in southern Ohio, and mine are thriving outdoors. Just keep them in full sun and keep them in a tray of standing *distilled* water, and they'll do great. Chemicals (chlorinated water and fertilizer) kill them. Other than that, just stuff them in the refrigerator from november through march for their dormancy period, cut off flower stalks (seedlings are very difficult to raise), and that's it. Most CPs are very low-maintenance plants. Flytraps and american pitcher plants are the easiest, and my favorites. Tropical pitcher plants are more impressive, but much harder to grow. Mokele

Correct, they get energy from sunlight like most plants. They capture insects for minerals and nutrients they can't get from the soil (carnivorous plants evolved carnivory to deal with very low nutrient soils). They need insects, but not more than a few a year. Of course, more bugs are good; my flytraps are all outdoors, eat like gluttons, and as a result last year I was able to divide my one flytrap into 4 plants, all of which are thriving. Mokele

Then he's a moron. Carnivorous plants either use enzymes to digest their food, or rely upon bacterial action or the digestive systems of symbiotic insects. No other plant has been of such systems. Normal plants produce 'food' from sunlight via photosynthesis, and absorb nutrients from the ground via their roots. These are distributed through the plant via the xylem and phloem (analagous to a circulatory system), but all breakdown and use of food and nutrients occurs within individual cells. There's no 'digestive system' in any non-carnivorous plant. Mokele

You can find conspiracies in anything, if you look hard enough. What they think is irrelevant. What does the evidence say? So far as I'm aware, there's no credible evidence to support their position, not to mention the fact that their only proposed alternative is so laughable I can scarcely believe they voiced it at all. I've read the objections he voices. They're weak at best; I've heard better from creationists, and similarly, all have been amply refuted by non-crackpot scientists. Smart people can believe really stupid things, and this is a case in point. Mokele

So you think bacteria feel pain?

The issue is the difference between 'feel' and 'pain'. Nociception is the detection of noxious stimuli, and is *not* equal to pain. Even bacteria are capable of nociception, and decapitated animals are respond to noxious stimuli. Additionally, at particular doses of morphine, human patients report being aware that something is damaging to them, but not feeling pain or distress. Several lines of evidence point to 'no brain, no pain', namely that pain is a mechanism employed by the brain to allow more efficient learning from noxious stimuli. Given the extreme simplicity of the insect nervous system and the superfluousness of the brain as anything more than an intergration center for sensory information and gross motor control, it seems highly unlikely that most insects can feel something that could effectively be called 'pain'. Mokele