Pointless things to do with animals
http://www.stuffonmycat.com/
My first dissensus post and I use it for this.
Regrets?
A few.
http://www.stuffonmycat.com/
My first dissensus post and I use it for this.
Regrets?
A few.
Bad-ass Animal Showdown
- Thread starter minikomi
- Start date
doesn't get much better
than this:
http://www.boingboing.net/2006/02/03/wasp_performs_roachb.html
this type of know-how stored in the Wasp's DNA is really fascinating...
it's a complex neuro-chemical procedure!
there has to be a precedent in order for the trait to be passed on
makes you wonder: how did the first Wasp figure it out?
than this:
http://www.boingboing.net/2006/02/03/wasp_performs_roachb.html
this type of know-how stored in the Wasp's DNA is really fascinating...
it's a complex neuro-chemical procedure!
there has to be a precedent in order for the trait to be passed on
makes you wonder: how did the first Wasp figure it out?
^ That's insane.
Do you know about the bacteria - a particular species, can't remember which, that infects ants. The bacteria makes it's way to the ant's "brain", where it grows slowly, and as it does so it invades the neurons in such a way as to modify the ant's behaviour, making it more prone to climbing up high objects (eg blade of grass). This makes the ant much more susceptible to being eaten by birds etc, thus propagating the bacteria to new regions...
Do you know about the bacteria - a particular species, can't remember which, that infects ants. The bacteria makes it's way to the ant's "brain", where it grows slowly, and as it does so it invades the neurons in such a way as to modify the ant's behaviour, making it more prone to climbing up high objects (eg blade of grass). This makes the ant much more susceptible to being eaten by birds etc, thus propagating the bacteria to new regions...
I don't think we know exactly how this kind of information is stored in the DNA. where is the "software program" kept in the bacteria?
like scientists don't know how viruses operate. virus cells are different from other cells in that it doesn't have a nucleus, where the instructions are kept. it is basically an outer layer filled with liquid or something like that. yet it knows exactly what to do to survive and propagate itself by penetrating a normal cell's wall, and chemically transform it to use for making more virus cells.
I may not be telling this 100% right... any micro-biologists around?
like scientists don't know how viruses operate. virus cells are different from other cells in that it doesn't have a nucleus, where the instructions are kept. it is basically an outer layer filled with liquid or something like that. yet it knows exactly what to do to survive and propagate itself by penetrating a normal cell's wall, and chemically transform it to use for making more virus cells.
I may not be telling this 100% right... any micro-biologists around?
oddly enough, yes . . well, plant viroligist in training really 
viruses are basically genetic material wholely reliant on their host to translate their coded messages and thereby hijack their host's, or create their own, machinery for replication. they can be naked DNA or RNA, or either coated in protein or even in membrane derrived from their host cell. how they replicate is really reliant on which virus it is.. and what kind of genetic information there is. for some - + sense DNA or double stranded DNA - the machinery is already in place within the cell they invade.. for others they have to have their own proteins they carry around with them to get the ball (or circle .. hehe.. i hope someone gets this) rolling so to speak.
other cool things are:
viroids - parasitic RNA which doesnt actually create any proteins, but are able to direct the replication machinery of their host through the SHAPE they form from folding up on itself! amazingly efficient packaging of information.. usually only about 2 - 300 base pairs which is SUPER small.
Prions - or proteinaceous infectious particle - are mishapen host proteins which poke into other proteins and cause them to be mis-shapen in the same way... and thus cause serious problems. think of an infectious protein game of tag.. mad cow disease is like this. theres some others in humans as well but they tend to only infect canibals who like to chow on brains!
viruses are basically genetic material wholely reliant on their host to translate their coded messages and thereby hijack their host's, or create their own, machinery for replication. they can be naked DNA or RNA, or either coated in protein or even in membrane derrived from their host cell. how they replicate is really reliant on which virus it is.. and what kind of genetic information there is. for some - + sense DNA or double stranded DNA - the machinery is already in place within the cell they invade.. for others they have to have their own proteins they carry around with them to get the ball (or circle .. hehe.. i hope someone gets this) rolling so to speak.
other cool things are:
viroids - parasitic RNA which doesnt actually create any proteins, but are able to direct the replication machinery of their host through the SHAPE they form from folding up on itself! amazingly efficient packaging of information.. usually only about 2 - 300 base pairs which is SUPER small.
Prions - or proteinaceous infectious particle - are mishapen host proteins which poke into other proteins and cause them to be mis-shapen in the same way... and thus cause serious problems. think of an infectious protein game of tag.. mad cow disease is like this. theres some others in humans as well but they tend to only infect canibals who like to chow on brains!
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Freakaholic
not just an addiction
minikomi said:
These Prions sound really interesting, so i did some snooping.
"Kuru
Imagine what it must be like to have a disease whose nickname is "laughing death." That's kuru, an exotic disease confined pretty much to the Fore tribe in northern regions of New Guinea. One custom of the Fore community was to eat the brains of dead relatives, a practice that promoted transmission of disease-causing prions. When cannibalism was banned, the incidence of Kuru was greatly reduced. When the kuru prion infects nerve cells, craziness and dementia, loss of coordination, and other symptoms develop."
from http://science-education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/prions/humanprion.html
so that's what you mean by "get the circle rolling"... ... (even more confused look) ... which means... virus cells reproduce in circular patterns?
can you explain the following a little further:
virus cells do have protein? but what about the second part, how can it's DNA be stored in the host?
ok what on earth are you bloody talking about.
can you explain the following a little further:
minikomi said:
minikomi said:
virus cells do have protein? but what about the second part, how can it's DNA be stored in the host?
minikomi said:
ok what on earth are you bloody talking about.
Paul Davies mentions in last week's New Scientist that some theorists have proposed that prions, viruses, viroids may be "relics of ancient alternative forms of life". How cool is that? Aliens in our midst.
http://www.newscientist.com/channel/life/mg18925381.600.html
http://www.newscientist.com/channel/life/mg18925381.600.html
confucius said:
erm.. some do! its a clever way to churn out a whole bunch of copies of their genetic information which gets chopped up into single copies later. like.. if you have a big stream of paper which goes through an ink coated roller with your document on it, thereby producing a lot of copies of the document which you can cut up later!
hmm viruses aren't cells. they're viruses.. the main difference being that cells are able to replicate themselves, whereas viruses are reliant on a cell to do the replicating for them. therefore they are in this kind of grey zone, not really alive but kind of!
a virus is kind of mobile information which gets into a cell (through whatever devious way it can!) and then tells the cell to how to make more virus.. it can be DNA or RNA, and have protein or not have protein. This really depends on the processes it uses! for example, a lot of cells have no way of replicating RNA, so a virus might carry around a special protein that, under host cell conditions, is able to change RNA into DNA which can then be used to make many many copies of the virus.
what i was talking about was a kind of virus called an 'enveloped virus' - these assemble within cells and then when they're ready, push out of their hosts and get pinched off in a little sphere of their host cell membrane, a process known as 'budding'. Influenza, for example, does this:
this was about viroids - they don't actually make any proteins but are pure RNA which is folded in such a way that they somehow are able to convince their host's proteins to replicate them! pretty amazing discovery. . and further pushes the envelope of the 'what is alive?' debate i reckon!
before we go any further it might be a good idea to get a basic grasp of genetic information flow - DNA to RNA to protein. also, this is a pretty well written introduction to viral structure i think - http://biology.about.com/library/weekly/aa110200a.htm
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HMGovt said:
unfortunately that bit of new scientist isnt working at the moment
i'll check it later!there was also a theory - the "RNA world hypothesis" - that RNA came first, then DNA then all the other things (like us!) which are basically just better ways to ensure that RNA sticks about! pretty mind bending... they say this because some RNA structures can perform simple genetic tasks like reproducing on their own... cutting themselves up...
check out: http://en.wikipedia.org/wiki/RNA_world_hypothesis
and http://en.wikipedia.org/wiki/Miller-Urey
seems to be debunked though.
interesting and informative. thanks Mini.
the RNA world hypothesis is very interesting. I like theories which drastically alter our perception of the world, and of our place in that world. it probably would not be a stretch to say that all the sciences are very much tainted by, if not entirely based on, the "specie-centric" view that humans love to take - that the world revolves around us.
the RNA world hypothesis is very interesting. I like theories which drastically alter our perception of the world, and of our place in that world. it probably would not be a stretch to say that all the sciences are very much tainted by, if not entirely based on, the "specie-centric" view that humans love to take - that the world revolves around us.
that RNA world theory is interesting, but yeah the wikipedia article does seem to point out rather a lot of difficulties with it!
The wikipedia entry on viroids, which I checked out, says that "The replication mechanism is quite unknown." - is this correct or not? Or is there evidence now that viroids replicate by inducing protein folding in the way you mention Minikomi?
The wikipedia entry on viroids, which I checked out, says that "The replication mechanism is quite unknown." - is this correct or not? Or is there evidence now that viroids replicate by inducing protein folding in the way you mention Minikomi?
a lot of it remains to be uncovered. some of the key enzymes for some of the varieties and some other things like some specific shapes the viroids degrade to under heat which seem to suggest seccondary structures important for replication have been discovered... but other than that people are pretty much in the dark..
hopefully everyone can access this:
http://tinyurl.com/b2ebp
but obviously it has to do with the shape of the RNA since the RNA does not encode for any proteins itself.
hopefully everyone can access this:
http://tinyurl.com/b2ebp
but obviously it has to do with the shape of the RNA since the RNA does not encode for any proteins itself.
"A monstrous discovery suggests that viruses, long regarded as lowly evolutionary latecomers, may have been the precursors of all life on Earth"
http://www.discover.com/issues/mar-06/cover/?page=1
http://www.discover.com/issues/mar-06/cover/?page=1
more on the exoparasitoid wasp
full article which explains WHY the wasp makes a zombie slave out of the roach:
http://loom.corante.com/archives/2006/02/02/the_wisdom_of_parasites.php
full article which explains WHY the wasp makes a zombie slave out of the roach:
http://loom.corante.com/archives/2006/02/02/the_wisdom_of_parasites.php