

CharonY
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Everything posted by CharonY
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I think in the US it is getting more vocal as the issue is being politicized here. In other countries there are generally no parties that have voting stake into supporting that (fundamentalist) stance. The reason why the arguments appear to get crazier is obviously that this is all that is left. To be honest, I was a bit apprehensive when starting to teach in the US, but neither me nor colleagues (including those specialized in evolutionary biology) have little trouble with students, indicating that at least among those interested in science the number of (vocal) creationists is low, even in the US.
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Archea before Bacteria?
CharonY replied to Elite Engineer's topic in Evolution, Morphology and Exobiology
Nope they are not placed after bacteria. That would imply that archaea are a group of bacteria. Current molecular (well, since Woese in the late 70s) evidence point to a common ancestor of archaea and bacteria, i.e they are different groups and are the result of an early split. Also note that many archaea are not extremophiles and there are also bacteria that are. -
This is an excellent point and a cautionary tale with regards to extrapolating certain biochemical processes to organismal or phenotypic changes.
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Crazy ants vs fire ants: a conflict spanning two continents
CharonY replied to CharonY's topic in Science News
I think the initial confusion was whether the fire ant venom would be called a venom? The application to themselves obviously would not classify it as a venom. However, they are able to spray it. There are actually a few more definitions being in used for venom, which does include presence of toxic proteins, for example, all of which would be the case for fire but not for crazy ants. However, spraying as mode of delivery is a bit of an issue. For example, spitting cobras are undoubtedly venomous. However, they can spray their venom which does harm without a delivery system into the body other than ingestion or absorption. And again, we see that these kind of definitions are often trickier than they appear (and more importantly, nature does not care for these distinction). Passive vs active are generally useful rule of thumbs, though experts in these areas would use some finer terms to distinguish between the mode of toxin production, delivery and mode of action. Edit: also crossposted. With regards to the nettles, most likely not, but it would be interesting to see how topical application to fire ant stings would work (or any mild acid for that matter), -
Crazy ants vs fire ants: a conflict spanning two continents
CharonY replied to CharonY's topic in Science News
No, it is used accurately. The distinction is normally based on delivery (simple thing to recall, if you bite it and you die => poison, if it bites you and you die => venom). Fire ants deliver their venom actively and are not simply covered in it. With regards to the mechanism It is possible that the formic acid denatures the proteins in the venom, though it is pretty much speculation at this point. Edit: I should add that fire ants also have stingers, albeit relatively delicate ones, compared to some of bigger ones out there. -
I agree, the methodology of the provided article appears to be more sound to me (judging from abstract alone). It is also interesting to note that fewer articles are likely to have a definite stance on AGW as all the evidence towards it and it appears a bit moot to ruminate on it.
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Found a neat paper about how tawny crazy ants (Nylanderia fulva) are able to take on and displace the aggressive fire ants (Solenopsis invicta). Apparently crazy ants somehow use formic acid that they produce themselves to somehow detoxify the strong venom produced by fire ants. While the crazy ants are now starting to displace the fire ants in the US, the arms race between those two species probably originated in South America where there habitats are overlapping. Article
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Depends on what information you have. If you have the drag force and the dimension of a sphere, it is quite straightforward to derive the dynamic viscosity (it is, after all, part of Stokes's law). Edit: cross-posted, but assuming you have settling velocity as measured parameter, deriving the equation is actually relatively straightforward. You just have to start with balancing the forces acting on a particle (drag, buoyancy and gravitational force). Since you have not posted the experimental setup to derive viscosity the question could also relate to what you would have to measure to derive viscosity. In the end it all boils down to get the drag force (and all the hints have already been shown here).
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Also note that publications are essentially open records. Eventually faults will be revealed if it is not possible to replicate results or if subsequent experiments fail to substantiate predictions. A common misconception is also that scientists are somehow all work together to keep their funding. The reality is that all are competing for the same money and the infighting between scientists can be vicious. There is no formal way to build a consensus but if many scientists independently and using different approaches come to same results, it will be used a consensus until a better explanation (e.g. model with better predictive powers) comes a long.
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Natural and Optimal Human habitat/habitats?
CharonY replied to Anopsology's topic in Evolution, Morphology and Exobiology
Indeed. Also living in the wild also involved utilizing resources efficiently. Even without technology (and seriously what level of tool use would be deemed "unnatural"?). Obviously migrating to somewhere where there is more game or more plants to eat would be more beneficial than staying at some place where resources are more limited? As being said but others, the particular viewpoint is a romantic view on naturalism and has as such little to do with actual events in nature. Animals move and spread and they have done it forever. And under the right circumstances adaptive radiation can occur rapidly. -
Tightly connected to growth are also weakish selective pressures (and high survival rates) that allow rare variants to persist. One should add that in this context "new" genetic variants indicates existence and persistence in a given population.. They may have well existed transiently before but got lost. I.e. the assumption is that there was not an unbroken line of transmission or that it was below the detection limit of traditional approaches.
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Natural and Optimal Human habitat/habitats?
CharonY replied to Anopsology's topic in Evolution, Morphology and Exobiology
Also think of invasive species. Being adapted to a certain habitat does not mean that one is unsuccessful in others. In some cases the opposite is true as one may rapidly fill ecological niches. Humans have the ability to transform the environment according to their needs and they can use instruments to a much higher degree than other animals. As such, habitats with more resources that can be transformed to their use (e.g. for agricultural purposes) or have more resources for manufacturing are better suited for humans than where they originally adapted to. -
Various cancer screens have been under scrutiny (including prostrate cancer). It is by far not the first study, but it certainly adds to the whole issue. In the end, it is a statistical problem. Cancer is still a relatively rare event and the false positive detection rate of screens is simply too high relative to that. Unless specificity of the diagnostic methods increase massively (and hopefully not the cancer rates), the impact on overall outcome is probably not going to be change much. Of course, a higher sensitivity and better early treatments could also contribute, though with low specificity overdiagnosis will remain an issue.
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Natural and Optimal Human habitat/habitats?
CharonY replied to Anopsology's topic in Evolution, Morphology and Exobiology
The premise is faulty. Many animals are migratory, even seasonal. Even if we only limit it to extant great apes (and thus ignoring migration in the past) we have two Pongo species (orangutan) in asia which have adapted to a more arboreal lifestyle than other great apes. Adapting to new ecological niches and migration are very common occurrences. Edit: aaand crossposted again. -
Help - a question on new species
CharonY replied to julianm's topic in Evolution, Morphology and Exobiology
That is precisely the point (and also why I mentioned the Kronforst et al paper. We do make distinctions that are useful in many cases but they do not necessarily reflect the amount of changes in allele frequencies. They are somewhat somewhat necessary for example to look at phylogeny as you need these (somewhat arbitrary) cut-offs to calculate distances, e.g. based on sequence similarities. This is especially relevant to keep in mind where reproduction is asexual. Edit: Crossposted with chadn737. -
Help - a question on new species
CharonY replied to julianm's topic in Evolution, Morphology and Exobiology
That is a bit misleading. One has to look at speciation on the population level. In principle a species does not evolve into another one. Instead, there must be a split within the population of sorts that results in reproductive isolation. I.e. generally one species does not become another over time but it splits (though one or the other can get extinct). In some cases, relatively few mutations are required as for example recently demonstrated for butterfly species (see Kronforst et al Cell reports 2013). Here the authors showed that initial divergence required only changes in a dozen or so loci though after the split genetic divergence accelerated (again, keeping in my mind that we are talking about populations here). -
On a similar note as Arete, assuming that you are applying for jobs you should focus on fit rather than technical abilities (also never assume you are the best at something). And fit is the whole package. If people don't like to work with you, your abilities are secondary. Work experience is valuable not only because it teaches you the skills you need on the job, but also because you learn to work with other people (most of the time) and in different work environments. Learning that makes one often much more hireable.
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That is one of the points that I would have highlighted. I.e. by re-framing the question you could highlight why the premise is wrong or at least misleading.
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Sona, I would suggest that you check the dates to threads you are replying to. OP has not been active for almost an year.
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That is not analogous as in this case the system is very clearly defined (i.e. enzyme, DNA, buffer system). In the case of the mice blood cell you have a) a more complex system and b) the idea behind it was to induce stress response in the cells. One of the responses was pluripotency. Originally, it was known from plant cells that this may occur, so it was not a matter of throwing random stuff at cells.
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That is very true. Times like these call for persistence and huge deal of flexibility.
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Read Phi's post again. He asked about how you are being perceive by others. I.e. he asked to try to put yourself in the perspective of others. Your answer is the same as every post you made. All about you, what you like etc. Things that you deem likeable in others are again all related to you. At best this appears narcissistic, which is very disruptive for a communicative situation. Communication is an exchange between people. That situation does not arise if you believe it is all about you.
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Well, for many applications a certain amount of purification is necessary e.g. to get rid of dimers though a simple column clean up is often more than efficient. Especially if you do lots of cloning (i.e. plates) you would like to have a certain amount of purity (again, I am no fan of gel purifcations myself). Inactivation of ligases is sometimes done for electroporation. Ligase binds to DNA (which you can see as a band shift in gel) which reduces electroporation efficiency. But I agree, for heat shock transformation it is pretty much a non-issue.
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If I had to guess I would have to think they may mean delusional. Or at least a very distinct lack of perspective and ability of reflection. For example:
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I find it weird that it is generally accepted that drunken driving is a bad thing but the same logic is lost with guns. How about drunken chainsaw wielding in public...?