Domain: nhm.ac.uk
Stories and comments across the archive that link to nhm.ac.uk.
Comments · 37
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Re:Plenty of other creatures haven't "evolved"I'm pretty dubious about this - and your assertion down-thread that the "American alligator" hasn't evolved for 150 million years" is frankly incredible.
I don't know where you're getting your palaeontology from, but you need better sources.
I'm not terribly up to scratch on the palaeontology of wasps, though I do recall that one of the large insect-rich deposits of amber is from Dominica and is about 35 million years old, so I'm going to hypothesise that you've got the far end of a "Chinese Whisper" which started with "organisms which look like modern wasps were found in (Dominican amber) which is 35 million years old".
I know my reptile evolutionary history somewhat better. While there were undoubtedly suchiform ("crocodile shaped") Suchian reptiles (ancestors of crocodiles) around 150 million years ago, that does not mean that they're the same species as the modern American alligator. At the very least, there was a modest burst of suchian evolution in the period shortly after the Cretaceous-Palaeocene boundary extinctions, which would very likely have affected many aspects of the lives of all large organisms that survived the end-Cretaceous events. Shortage of large prey would have made dwarfism a common strategy for tens of millennia, followed by an opportunity for the suchians to become the dominant land animals. Which they would have been in competition with phorusrachid "terror-birds" and mammals. It's arguable if the mammals (about 6000 species) or the birds (nearly 10000 species) won that race.
A few years ago I had the pleasure (I'm a geologist - I have
... abnormal ... pleasures) of spending an afternoon going through the Natural History Museum's cabinets of fossil coelocanths from the Mesozoic, and comparing them with the 1960-odd specimen in the main hall of the museum. From personal observation I can assert that this famous "living fossil" has changed over the 90-odd million years during which we haven't had a fossil record for it. For a start, it's about 4 times the size of it's older relatives. -
Re:very understandable
This page is a list of confirmed native spiders which bite in the UK. None are deadly (apart from the possibility of anaphylactic shock), but they are poisonous.
Of the native species, I'd guess these four (here, here, here, and here) would be the ones to be most concerned about, because of distribution and severeness of bite. None are really nasty, though.
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Extinct again
I hope they keep a few captive, because otherwise they will go extinct again the first time that artificial mist breaks down (things tend to break in time, especially in the tropics).
Actually, a bit of googling told me this happened before in 2003. -
Re:Question...
Someone else linked to this
http://www.nhm.ac.uk/resources-rx/files/12feat_dna_in_amber-3009.pdf
NHM: What do you think about Dr. David L. Stearn's recent prediction that in years to come DNA mapping techniques will enable scientists to map a complete dinosaur DNA sequence by working backwards from the DNA sequences that they will eventually unravel for birds, reptiles and mammals?
Austin: Scientists have successfully mapped the complete DNA sequence for two bacteria (Haemophilus influenzae and Methanococcus jannaschii), a yeast ( Saccharomyces cerevisae) and nematode worm ( Caenorhabditis elegans) and there are research projects under way to try and map the complete DNA sequence for humans and the fruit fly Drosophila but they will take years to complete. The Human Genome Project, for example, has research teams collaborating around
the world to map the three billion base pairs that constitute the human DNA sequence but even with this collaborative effort it will have taken close to fifteen years to complete. Although it may be possible to map the DNA sequences for birds, reptiles and mammals in theory, I'm not convinced that this is going to happen in the near future for reasons of the enormous cost and effort involved. And even if complete genome sequences were available for living mammals,
birds and reptiles predicting the sequence of a dinosaur genome with any degree of accuracy would be an impossibly complex task. Think of the dinosaur sequence that we are trying to predict as a hypothetical jigsaw puzzle made up of more than one billion pieces and each piece instead of being a flat piece of card is a cube with a different fragment of the overall picture on each side. So to reconstruct this jigsaw puzzle you not only need to position all the pieces in the correct place, you
have to have the correct face showing too. That's how impossible the problem is!What I'm surprised about is that it is not impossible, just computationally intensive to "de-evolve" organisms back to their ancestors. You'd think this process would be impossible since evolution is lossy - i.e. genes get deleted along the way.
Of course you don't necessarily need to accurately de-evolve a bird to its dinosaur ancestor, you could just work out how to turn on dinosaur like modes in bird DNA. So you could essentially make a T rex by changing the genes that control size, teeth etc.
Your T Rex wouldn't be genuine of course, it would be a recreation. Still, who cares? It's not like we need it to be able to breed with genuine Cretaceous era Rexs.
Going back to Jurassic Park in one of the movies Sam Neill's character actually says that the dinosaurs in Jurassic Park aren't genuine either, they are just monsters made in a lab.
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Re:No water, no air, no bonds broken?
"there were several reports, including the one in 1992, that claimed that DNA fragments had been recovered from insects that had died between 25 and 125 million years ago. These reports caused considerable excitement, but despite intensive efforts no other researchers, including the team at The Natural History Museum, have been able to repeat and verify these results. As a result of these findings, most scientists now agree that DNA doesn't survive in fossilized insects in amber."
http://www.nhm.ac.uk/resources-rx/files/12feat_dna_in_amber-3009.pdf
Short answer: It was plausible, but now is considered debunked. Unless a dino got frozen for 150 mega-years, there's no Jurassic to be. -
Re:JP
No time soon. Despite earlier signs, there has been no legitimate DNA recovery from the Mesozoic, the time of the dinosaurs. All the earlier discoveries from amber of that age have turned out to be bogus, as have claims of obtaining DNA from dinosaur bone (it was contamination). In fact, the story is the same for most younger examples too. The oldest legitimate DNA is no more than a few tens of thousands of years old, and very fragmentary. So, we may get information from mammoths, moas, and giant sloths of the Pleistocene, but apparently nothing from extinct dinosaurs. Check this paper [PDF] and this one [PDF] for short reviews, and this one for a longer review.
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Cool Natural Materials...
Lots of natural materials exhibit really interesting properties, sometimes at odds with the way we'd expect such materials to react. For example crustacean shells are ceramic but quite tough because of the layering of the ceramic with small amounts of organic binder material which causes any fractures to be diverted before they spread though the bulk of the material.
Many natural materials exhibit high levels of hierarchy like this and it's one of the many reasons why natural structures and materials are way cooler than most of the things that we make, with the possible exception of aerogel. One of the most interesting hierarchical structures is Euplectella Aspergillum (Venus' flower basket), its structure is really complex. I can easily see this being an aerospace material in 10 years...
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Re:Intellectual Ventures?
But sometime before I die, I would like to be able to use the phrase, "my personal submersible" if only for the way it makes my mouth feel to say those words.
There are machines that fit the definition of a "personal submersible" which only cost around a thousand IBT (note at foot of message)
These are rather like underwater mopeds with a head/ shoulders shroud which is supplied with air by a SCUBA system (there's also a "bail-out bottle" in the ones I've seen advertised) ; this provides buoyancy at the top ; a waterproof housing with a car battery hangs at the bottom ; the two are joined by solid body incorporating a moped-like seat, with several thrusters in the body and steering controls for the user. Allegedly, no training is necessary. 10m depth limit though.
If you're not into SCUBA, they're not unbelievably expensive - I saw them advertised for tourist trips at moderately interesting prices on a Tenerife beach promenade, but I was getting my SCUBA ticket. (If you are into SCUBA
... you don't need this.)I suppose I'd better RTFA now. Bad form, I know.
Fricke never observed reproduction, predation or juveniles, but believes the total Comoros population holds 300 to 400 individualsâ"a number he regards as viable.
As a population base, that's probably viable. But seeing no juveniles for what is obviously a long-lived period species
... that's a cause for concern. Ah ... but later there are reports of juveniles seen deeper using an un-manned ROV. Which makes perfect sense - it's not uncommon for juveniles and adults to have substantially different habitats and life styles.Using Fricke's customized submersible JAGO
Fricke's sub ; not Allen's.
[...]To explore potential juvenile and adult habitat deeper than Fricke's census area, Paul Allen - the cofounder of Microsoft - lent his ROV to Fricke for three dives.
An ROV system in this sort of depth capability range could only cost a few 10s of thousand IBTs. Substantial, but far less than the "JAGO" submarine. It'd need less deck space too, which is really important.
In commenting on the original article, I mentioned this book, which is the current standard reference on fossil coelacanths. (Dr Forey, the author, is "Prof Coelacanth" at the NHM as much as Richard Fortey is "Prof. Trilobite" ; by all accounts I've heard of Prof.Trilobite in "lecture mode", the easiest way to distinguish the two is that one has a beard and is talking about something recognisably fishy, while the other is clean-shaven and talking about something with no good modern comparison. Mad as hatters, both of them. In a good sense.) I'm sure that Dr Forey has noted Fricke's work for inclusion in the next edition of his monograph.
[Note : IBT = International Beer Token ; while the absolute cost of a beer varies around the world, relative to other commodities it's less variable. A "beer" is equivalent to about 3-4 loaves of bread ; 1.25 "beers" plus the son of your deity of choice will feed around 1/5th milli-crowd ; a "beer" is approximately equivalent to 6-8 ready-rolled cigarettes.
Well, I find it useful. I also use the IBT concept for comparing pay rates in different continents to decide which jobs to accept.]
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Re:Previous genetic evidence
Similar hypotheses have been suggested based on genetic evidence which suggested that humans and neanderthals interbred. See http://www.nhm.ac.uk/about-us/news/2010/may/first-genetic-code-of-neanderthal-reveals-inbreeding66724.html. In both cases, the work has been done by Chris Stringer who seems to focus a lot on this hypothesis. Stringer is a very respected anthropologist who was responsible for formulating a lot of the now accepted ideas about how homonids spread from Africa in successive waves of migrations.
In addition to that, we know that the ancestors of the Melanesian population interbred with the Denisovan hominids. To add more interesting stuff to the cauldron, it appears that the Neanderthals not only interbred with H. Sapiens but with the Denisovans as well. Stone-age interspecial threesome man!
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Previous genetic evidence
Similar hypotheses have been suggested based on genetic evidence which suggested that humans and neanderthals interbred. See http://www.nhm.ac.uk/about-us/news/2010/may/first-genetic-code-of-neanderthal-reveals-inbreeding66724.html. In both cases, the work has been done by Chris Stringer who seems to focus a lot on this hypothesis. Stringer is a very respected anthropologist who was responsible for formulating a lot of the now accepted ideas about how homonids spread from Africa in successive waves of migrations.
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Re:Have a great trip!
Definitely
... taking the water taxi from Embankment to Greenwich is something my mother always does when she visits. It's a great way to see the sites of London.I'll add my voice to the chorus for the Science Museum, and also the Natural History Museum. No geek should avoid going to these two! The British Museum is great fun, too.
Overall, it largely depends on what sort of geeky things you go for. Check out Pollock's Toy Museum if you're into games and construction toys. If you're into trains, check out the London Transport Museum. If you're into military, there's the Imperial History Museum, or the Royal Air Force Museum. The Design Museum is pretty cool, too. If you're into history, checkout the Museum of London, which is a history of the city. Also, the Victoria and Albert Museum is also pretty interesting. More about arts and crafts, though.
Otherwise, there's also loads of art stuff, like Tate Modern, the National Gallery
...Have fun!
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The National History Museum
Don't miss it! It has a new Darwin Centre with the Cocoon. You can watch scientists at work and talk to them. And it is free.
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The National History Museum
Don't miss it! It has a new Darwin Centre with the Cocoon. You can watch scientists at work and talk to them. And it is free.
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The National History Museum
Don't miss it! It has a new Darwin Centre with the Cocoon. You can watch scientists at work and talk to them. And it is free.
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Re:Indy Children's Museum
I don't know about the US, but maybe the largest ones in big cities would be better?
http://www.sciencemuseum.org.uk/
(There are exhibits for kids, but I'd guess 8 is the youngest that anything is targeted at.)Also, the adjacent Natural History Museum: http://www.nhm.ac.uk/
The "kids only" section has mostly "take a look at the [x] exhibit".Both are free (so is the Victoria and Albert Museum, opposite, but that's human history/artefacts.)
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Termites A_R_E cockroaches ...
Termites are related to cockroaches
Quote:
"Termites have long baffled scientists as to their place in the natural world and their relationship with other insects. Although they are part of a large 'superorder' that includes cockroaches, they were classified separately in a group called Isoptera .
This new research puts termites into the same group as cockroaches, (Blattodea). Termites are now classed as a new family of cockroaches called Termitidae . Isoptera is no longer valid."
Well, I always preferred ants, though, admittedly, termites are superb architects when it comes to thermoregulation.
CC. -
Re:Land vs. Sea evolution
In the case of both the Coelacanth and Tuatara, the modern animals just bear a very strong resemblence to their fossil counterparts.
I've never got up-close and personal with a tuatara, but I did specially go to the NHM a couple of years ago to look at coelacanths. Now, I don't claim to be an ichthyologist (why do you think I went to the NHM, which does house and feed real ichthyologists?), but even I could see the differences between late Jurassic coelacanths in the specimen cabinets in the back room (well, East wing) and the Recent one stuffed in the hallway.
Yes, Latimeria is indubitably a coelacanth. But it isn't particularly similar to the last of the fossil coelacanths (Macropoma, for example); it's more similar to some coelacanths from the Permian. -
Re:Mars missions
Even if I could only see a marsrock in the Smithsonian, it would make me feel so much closer to the Red Planet.
No idea about the Smithsonian, but I've already seen Mars rock - at the Natural History Museum in London.
Bits blasted off Mars in some titanic collision aeons in the past, which have drifted through space before falling to Earth as meteorites. Bit of a roundabout route, but it works!
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Re:Better Reasons Exist than Mobile 'Phones
Sadly, in the UK, habitat destruction due to urbanisation means that bumble bee numbers are declining - there used to be 19 or 20 UK species, 3 have apparently gone extinct in the past century. If you have a real garden (I know, luxury these days), please don't keep it totally pristine, allow a few wildflowers/weeds to flourish in a forgotten corner, an overgrown earthy bank is ideal (bumble bees burrow to make their nests!). This will bring both wild bees and butterflies - the UK and Ireland have a wide range of spectacular but now extremely rare butterfly species.
Even worse, bumble bees love to spend lazy summer days sunbathing on exposed rocks. And concrete pavements and roads look like exposed rocks to them -> lots of squashed bees :-(.
Yes, bumble bees have stings and can sting multiple times. But they won't sting unless you *really* go out of your way to piss them off, they are normally amazingly docile and tolerant of humans, even small children trying to pet them. :-)
Indeed, bumble bees do grow to magnificent size in Ireland - Ireland still has many small pockets of semi-wild areas (the residents of the Emerald Isle do like their greenery...), and fragmentation rather than outright destruction of habitat isn't too much of problem, as bumble bees, though hilarious looking, do fly. -
Re:Actually... I don't think it is pointless...
I don't think I'll reply in detail to everything. I'll just point out that fossils. regardless how you interpret them are very widespread. There are in fact few places of this planet that do NOT have fossils.
Not generally fossils but, areas where specific fossils are not found. If you are in a layer of rock formed in the Precambrian you aren't going to find any bones. Due to certain issues with the oceans we don't find many fossils in the water.
Even if they made some petrified wood, is that the way it really formed? Time is the biggest enemy of fossil making. The is NO known mechanism for making fossils over long periods of time - period. Using fossils, any fossils, as evidence for evolution is a wishful fairy tale.
No petrified wood forms in a very specific way, we simply made the fossilized wood by forcing the process to happen in a few days rather than a large number of years. Having extra time at your disposal wouldn't cause an inability to make fossils. That's just stupid. Secondly, there are many well understood chemical and physical properties which lead to fossil formation.
http://www.safossils.com/fossil.html
http://www.scsc.k12.ar.us/TuttS/fossil_formation.h tm
http://www.museum.vic.gov.au/prehistoric/what/howf ormed.html
http://www.fossils-facts-and-finds.com/how_are_fos sils_formed.html
http://www.nhm.ac.uk/nature-online/earth/fossils/f ossil-folklore/how_are_fossils.htm
http://www.fossil.energy.gov/education/energylesso ns/coal/gen_howformed.html
Really, it isn't hard to figure out.
(....from multiple radiological clocks...)
To use any clock, you have to assume (believe = have faith) that your clock has always ticked at the same or a known rate over the total time measured.
No. That's why one uses multiple clocks. Firstly, sometimes there are slight (1% or so) fluctuation in the initial content of the radiological clock material. One need only believe that all of these radiological decay rates from the half a dozen methods you use remain constant, as would be expected if the laws of physics hold roughly true. Though, to be fair, they have only held true each and every time we checked, perhaps they magically stop working when we aren't looking.
There is evidence that clocks based on atomic properties have drifted as much as by a factor of 300 million times since the "big bang". This drift is related to very fundamental properties of space itself changing as the universe expanded.
Respectfully, no there is not. It took a long while before heavier radioactive particles even formed and from that time, the half lives have remained constant. It is extremely silly to suggest other wise with "there is evidence", as if that is some forgiving phrase with which to preface lies.
The equations for atomic behavior include Planks constant. Evidence that evolutionists like to keep silent shows that the some of the so called "constants" are anything but constant over long time periods. There are few things in nature that are really constant other than change itself. So your clocks are based on faith.
There may have been some slight change in such things as Planks and the speed of light, these are really really small and only true for the first split second of time. Radiological decay and half-lives are extremely consistent. The idea that some error exists and thus the universe is 6,000 years old is downri -
Re:wtf
Teeth are an interesting problem, but someone could always offer crazy interpretations of them as capable of plant eating. I'd rather see them explain the A) huge, probable T. rex coprolite with crushed up bone in it, B) the stomach contents of the Coelophysis found at Ghost Ranch in New Mexico -- the rib cage area contains bones of their last meal (originally thought to be of the same species, but maybe a type of crocodile-like creature instead), C) the stomach contents of Compsognathus from Solnhofen in Germany (probably a type of lizard), or D) the bite marks on dinosaur bones found at a site in Madagascar.
It's fine (though crazily unlikely) to hypothetically propose T. rex and other sharp-toothed dinosaurs could have used their teeth to eat plants, but when the stomach contents, bite marks, and their poop imply a meat-eating diet, then that hypothesis is quickly negated by the evidence. -
Re:Darwinsim = Science?
Johanson discovered an Australopithecus afarensis from the bones that he found, because he was trying to build one. From the article linked, you can read further down that some of the bones were found "up a slope" from where he found the original hominid bone.
It's quite likely that instead of discovering a complete (complete enough for forensic study) transitional hominid skeleton, Johanson instead found a skeleton of an ape, and a few human bones.
So one bone is found down a slope, anda ll of the rest are found together. Could you perhaps point out which of these bones is the human bone amidst the rest of the ape skeleton?
This simply because he was itching to find something he learned had to be there from his 15-20 years of evolutionary thought brainwashing.
The nice thing about any science is that all discoveries and claims are subject to "peer review". Perhaps you could explain how peer review failed to catch what you claim happened? Or is every biologist on the planet "brainwashed"? That's a rather convenient excuse for you to use when handwaving away evidence -- say that anything that leads to conclusions that you don't like is the result of "brainwashing". Almost makes me wonder if you've just got it set in your head that evolution is false and you're looking for any reason to dismiss evidence that you might possibly be wrong. What's that word? Oh, yes, "brainwashed".
Evolutionary theory lies outside of empirical science, simply because experimentation is not possible
This statement is simply false. Experimentation does not require that the entire process be duplicated. Predictions of observations that would naturally arise as a result of a process can help validate a theory. Example: ERV insertion points in non-coding regions of primate DNA. Any ERV insertion at the same place in "old world" monkeys and "new world" monkeys will also be found in apes. Any ERV insertion in orangutangs and chimpanzees will also be found in humans. Predictions of genetic markers such as this were made before DNA sequencing was done, and validated afterwards. The most rational explanation for these identical markers in non-coding regions is established lineages of common descent. -
Re:Is this new?
"If they are just trying these techniques now, then paleontologists need to start visiting with other departments. The sciences have evolved so much over they last 20 years that in order to do any real work you have to associate with people outside your discipline."
I could make a joke about paleontologists and geologists moving very slowly, but it wouldn't really apply here.
Actually, this is far from the first work using confocal microscopy on fossils. The article carefully points out that this is the first time it has been applied to fossils this old (i.e. this deep in the Precambrian), which is probably right, but paleontologists have been using confocal microscopy on younger microfossils for years now, though it isn't as commonly applied as it probably could be (e.g., see this article on fossil dinoflagellates and this catalogue of re-imaged type specimens). They've also used serial sectioning techniques for decades, and having access to something 3D is much more versitile than the old way (which was to make a scaled physical model from the information in the slices). Various types of CT scanning techniques are used if the object is big enough. The Raman spectroscopy application is fairly new, but usually ordinary optical mineralogy thin sections provide compositional information. It is only when you want to do a non-destructive technique that it would become important.
"Now, with fossils, I assume that you can only see the very top layer, because light wont penetrate rock that far."
Actually, most of the common minerals involved in fossilization are variably transparent at that scale (quartz, calcite, etc.), sometimes almost crystal clear (no pun intended). Geologists of all types (not only paleontologists) regularly make "thin sections" of rock that are a standard 30 microns thick or so. Also, many organic-walled microfossils are entirely extracted from the rock (like the dinoflagellates mentioned above, or fossil pollen and spores), so you can immerse them in whatever media you like, including standard biological mounting media. Being derived from biological cells, they fall in the same sort of size ranges and are tens to hundreds of microns in size anyway.
Bottom line, confocal microscopy works great for many of them, and as these imaging techniques have progressed, paleontologists have been applying them. I'm sure there are a great many discoveries left to be made as the use of such techniques slowly becomes more pervasive. -
Re:Is this new?
"If they are just trying these techniques now, then paleontologists need to start visiting with other departments. The sciences have evolved so much over they last 20 years that in order to do any real work you have to associate with people outside your discipline."
I could make a joke about paleontologists and geologists moving very slowly, but it wouldn't really apply here.
Actually, this is far from the first work using confocal microscopy on fossils. The article carefully points out that this is the first time it has been applied to fossils this old (i.e. this deep in the Precambrian), which is probably right, but paleontologists have been using confocal microscopy on younger microfossils for years now, though it isn't as commonly applied as it probably could be (e.g., see this article on fossil dinoflagellates and this catalogue of re-imaged type specimens). They've also used serial sectioning techniques for decades, and having access to something 3D is much more versitile than the old way (which was to make a scaled physical model from the information in the slices). Various types of CT scanning techniques are used if the object is big enough. The Raman spectroscopy application is fairly new, but usually ordinary optical mineralogy thin sections provide compositional information. It is only when you want to do a non-destructive technique that it would become important.
"Now, with fossils, I assume that you can only see the very top layer, because light wont penetrate rock that far."
Actually, most of the common minerals involved in fossilization are variably transparent at that scale (quartz, calcite, etc.), sometimes almost crystal clear (no pun intended). Geologists of all types (not only paleontologists) regularly make "thin sections" of rock that are a standard 30 microns thick or so. Also, many organic-walled microfossils are entirely extracted from the rock (like the dinoflagellates mentioned above, or fossil pollen and spores), so you can immerse them in whatever media you like, including standard biological mounting media. Being derived from biological cells, they fall in the same sort of size ranges and are tens to hundreds of microns in size anyway.
Bottom line, confocal microscopy works great for many of them, and as these imaging techniques have progressed, paleontologists have been applying them. I'm sure there are a great many discoveries left to be made as the use of such techniques slowly becomes more pervasive. -
things you've always wanted to know about penguins...but was afraid to ask...
From the study Pressures produced when penguins poohcalculations on avian defaecation :
Although the orificium venti generally opens through a horizontal slit in the Spheniscidae, the orifice becomes circular during evacuation (King 1981; Watson 1883).
Here's proof?
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Re:Here we go again...
Here's an article that sums up macroevolution as an interdisciplinary subject. Yes, macroevolution is a neo-Darwinist concept, but everything I said about macroevolution being thus far unobserved can be transferred to punctuated equilibrium, for example.
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beware of the penguin terrorists...
...and their weapons of mass destruction.
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Re:Winter on Mars?
I think that the tilt of the earth's axis relative to the orbital plane causing winter/summer is not the same mechanism on mars.
I think it probably has more to do with Mars having a somewhat eliptical orbit:
http://www.nhm.ac.uk/mineralogy/mars/Marshtml/2orb italparameters.html -
Re:Planting Life
I'm pretty sure the highs get well above -40 C in the temperate and equitorial areas.
Apparently it can get up to 25 degrees celsius. We'd be lucky to get that during summer in some northern parts of the UK :) Tho even in the warmest parts of Mars it still get VERY cold at night.
See here for some info. -
Raptor
i know it means bird of prey, but did anyone else think of this when they read the headline about a giant raptor?
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donate it...try here... The Natural History Museum in London
I bet that they would put your grandfather's name on the sign that describes it and such... Not to be cold, and very sorry for your loss, but it would kind of immortalize him in a little way.
Duke
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How we know that SNC meteorites come from Mars.
There have been a lot of questions about how we know that SNC (or Martian) meteorites come from Mars. This used to be a bit of a "hot topic" in planetary science, but over the last few years an international consensus has arisen supporting the hypothesis that these meteorites come from Mars.
The clearest explanation I can find for this can be found at http://www.nhm.ac.uk/mineralogy/grady/mars.htm- the author, Monica Grady, is one fo the world's leading authorities in this field.
In short, the ratios of the three stable isotopes of oxygen (16, 17 and 18) are characteristic for any given planet. The SNC meteorites contain small quantities of atmospheric gases within isolated pockets. Since the oxygen isotopic composition of these gases have been shown to be different from that of the Earth, they cannot have come from here, leaving Mars as the a viable proposition for the meteorites' origin. This is supported by measurements of the isotopic composition of Mars' atmosphere by the viking landers.
I hope that answers some of your questions.
Regards,
-Karl
Dr Karl Mitchell
Planetary Science Research Group
Environmental Science Dept.
Lancaster University
UK
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Re:Not a squid
All tentacles are of same size
This would not necessarily be unique to this squid. Vampyroteuthis infernalis (OK, not technically a "squid", but a cephalopod) appears to have eight arms of equal length, until you examine it very closely. (As a side note, Vampyroteuthis is ugly as sin.) Then again, we barely know what this thing is yet. Vampyroteuthis was originally thought to be an octopus, and is considered to have rather jellyfish-like behavior, and ended up getting put in its own taxonomic category, so the magnapinnidae could be something in their own class too.As for "no eyes visible" and "transparent"...we've got one not-very-good photo; the scientists say they videotaped it for up to ten minutes. I think I'll go with their judgement. Besides which eyelessness is not unknown among deep-sea creatures either, like the hagfish. So, an eyeless, mostly symmetric squid that behaves like a jellyfish...it would be a weird squid, but it could still be one.
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Re:Not a squid
All tentacles are of same size
This would not necessarily be unique to this squid. Vampyroteuthis infernalis (OK, not technically a "squid", but a cephalopod) appears to have eight arms of equal length, until you examine it very closely. (As a side note, Vampyroteuthis is ugly as sin.) Then again, we barely know what this thing is yet. Vampyroteuthis was originally thought to be an octopus, and is considered to have rather jellyfish-like behavior, and ended up getting put in its own taxonomic category, so the magnapinnidae could be something in their own class too.As for "no eyes visible" and "transparent"...we've got one not-very-good photo; the scientists say they videotaped it for up to ten minutes. I think I'll go with their judgement. Besides which eyelessness is not unknown among deep-sea creatures either, like the hagfish. So, an eyeless, mostly symmetric squid that behaves like a jellyfish...it would be a weird squid, but it could still be one.
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Re:Seriously....
Europa does have very likely evidence of a liquid ocean, but the article then uses that to 'assume' of living creatures there (bac). How can there be?
While I would be the first to argue that we have no proof of life, the martian meteorites not withstanding, Europa is probably our "best bet" to find it inside our own solar system.
For instance have a look at these papers from the AAS DPS meeting,
- Infrared spectra of extremophile bacteria under Europan conditions and their astrobiological significance
- Europa, Convection, Tidal Heating, and Astrobiology
or even
Al. -
Re:Just as good, eh?
-
Alternatively
In Britain some museums (eg the Natural History Museum) are counted as academic institutions so they appear in
.ac.uk along with the universities. Strangely, the next-door Science Museum seems not to appreciate this and is redirecting from its old nmsi.ac.uk domain to something much less classy. Darn, that Slashdot goatse indicator is spoiling the surprise of clicking on the links to find out what the domains actually are :-(.