There's a group of parasitiod Hymenopteras called The Jewel Wasps, Nansonia. They like to lay there eggs in or on other insects, where the larvae will exploit their host's nutrients, which in the end leads to the host's death. I've written about similar systems before.
What I haven't written about (because I didn't know it until now) is the very facinating background of how three species, N, vitripennis, N. giraulti and N. longicornis, are reproductively isolated in nature (they can't produce any offspring, basically). Usually, reproductive isolation is a result of the genetic conflicts of the gametes (egg and spermcells), making embryonic development impossible or severely harder. Or, as in moths, reproductive isolation is the result of the species using different chemicals (pheromones!) to find eachother for mating. There are many more quite easy-to-comprehend examples of the beckground to reproductive isolation. But now I've found this information about the three Nansonia species.
Some more background is needed though, before I get to the basis of what I'd like to say: in some insects, a certain type of bacteria has somewhere along the evolutionary line managed to infect and stay put in the insects cells. The bacterium, known as Wolbachia, has then gradually evolved in sync with the insect so that it becomes kind of symbiont (endosymbiosis - a phenomenon that has led to the mitochondria found in plant, fungi and animal cells, as well as the chloroplasts in plant cells). The different insect species therefore have different variations of Wolbachia. Well, it turns out that in the three Nansonia species, it's their species specific Wolbachia that causes reproductive isolation. Because if the Wolbachia is removed (using antibiotics) the species are suddenly able to breed and produce fertile offspring. I don't know about you but for me this is SO cool. Yes, I'm odd.
Source:
Genome Mapping and Genomics in Animals, Volume 1
Wayne Hunter, Chittaranjan Kole (Editors)
Genome Mapping and Genomics in Arthropods
C H A P T E R 3
The Jewel Wasp – Nasonia
Jürgen Gadau, Oliver Niehuis, Aitana Peire, John H. Werren, Emmanuelle Baudry, and Leo W. Beukeboom
2009-01-30
2009-01-26
Itsy bitsy spider
Image taken from http://scienceblogs.com/pharyngula/2006/03/spider_kama_sutra.phpLiving in a more or less religion-influenced society, it's easy to judge our culture as becoming more and more obsessed in things regarding mating. Girls show off bums and hill-look-a-like body parts, boys try to excell by showing off how good of a catch that they are, commersials try to sell just about everything by giving it a touch of mating-indications. This may be percieved as vulgar and cheap to many of us, but in the spotlight of evolution it's really a good concept because this will pass on genes for ever and ever (although they will be changed over time).
As I've mentioned before, there's plenty of variation among mating systems, and everything seems to be allowed as long as it yields offspring of reproductive value. The spider Homalonychus theologus for example, has a thing for bondage, which might be a word of perverse indications to some of us. This does not become H. theologus, who's life is dictated by other matters than morals and family values. When the male approaches a female, he wraps her legs in silk before proceeding with mating. This behaviour can be found in other spiders as well (Xysticus, Tibellus, Latrodectus, Dictyna, Oxyopes and Nephila maculata).
Basically, it's quite "easy" to come up with theories to why "weird" mating systems arise:
1. We have a group of interbreeding individuals.
2. In one of the individuals, a mutation (or mutations) is induced in it's gametes (sperm and egg cells).
3. The resulting offspring bearing this mutations has a deviation from the original mating system due to this.
4. The mating deviation causes this individual to be able to mate more, mate more succesfully, or mate in any other way that will increase it's ability to produce offspring.
5. The offspring (or atleast some of them, depending on the nature of the mutation) will inherit it's parent mating system deviation and thus have a reproductive advantage to the individuals without the mutation.
6. Over time (without taking other evolutionary factors in regard, such as genetic drift) this mutation will increase in frequency and become normal.
Since humans are cultural beings, it's not very easy or wise to try to explain all our "deviation" with genetics. But the fact that sex sells is very easy, because liking to reproduce (sex) generally means (in a world without contraceptives....as in 50 years ago and backwards in time) a lot of kids, which means a lot of kids growing up to liking to reproduce and so forth. So don't blame our world todaty, if you don't like what you see; blame our ancestors. But then, if they'd listened to your possible arguments, you may not have been born. Ever.
(Of course it's good to question everything, especially the media and fields out to exploit your wallet, but questioning everything ad absurdum will not lead us anywhere than to supression of innate behavioural factors).
Source: http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1636%2FM03-4&ct=1
2009-01-19
Hear yourself
Have you ever thought about why your voice is sounding different when you hear it in a recorded version, than when you hear it "live" on everyday basis? I have, but I haven't really bothered to seek information about this. I get kind of scared when I hear recordings of my voice. I sound so naive, so young (well...I suppose I'm still young, scince I'm only 25) and very dorky. Others (boys in particular) think I sound cute. Not what I'm going for.
Well, well. The reason I believe that my voice is darker than it is is that when I'm talking, the sound waves travels through two media - air (from my mouth and around into the ear) and bone (from the inside of my mouth and inwards to the ear). And since bone enhance deeper, lower- frequency vibrations than air does, I precieve my voice as darker. This part of sound transfer goes away when I am listening to my voice though a recorder (or someone else's voice), therefore I hear it as being lighter. But still, this is a win information for me. Because now I've been enlightened that the voice I hear in my head is really my true voice, and it's all you others who can't hear it this way (unless I talk through your bones, which I don't know how to do). So I'm really not that cute at all.
An additional remark to this is that now it makes sense; why all lousy, tone-deaf people turn up at the American Idol-try outs.
Source: http://www.sciam.com/article.cfm?id=why-does-my-voice-sound-different
2009-01-16
The nose was ugly, long, and big, Broad and snouty like a pig
Image taken from: http://www.tolweb.org/tree/This could be the cutest insect I've ever stumbled over. It's known to us westernized humans as Curculionidae curculio spp, a weevil with hair, from what I can see from the picture. I can't find any information about this particular species, but weevils are the largest group of beetles with over 60,000 species. I am kind of facinated by its antennae that is placed on its snout, rather than on the head (as I'm used to, when seeing an insect).
Life on Mars
It seems like there's been some indication of life on Mars. This due to recordings of methane plumes from particular areas, which should be a hint that there's microbes living there. Similar areas on earth are places where microbes are bubbeling up gas, so if you put two and two together then you might can call up David Bowie and say "yes, there is life on Mars".
Source:
http://www.sciencemag.org/cgi/content/abstract/1165243
http://blogs.discovermagazine.com/loom/2009/01/15/live-blogging-the-mars-methane-mystery-aliens-at-last/
2009-01-14
Buy what very big eyes you have...
Have a look at the eyes of this spook(y)fish, Dolichopteryx longipes. Isn't it awsome? This is the first vertebrate found that uses this type of eyes, which has mirrors instead of lenses to focus the incoming light. Although you can count to four eyes when looking at the fish, it's actually just two eyes that are divided into two parts each, making it possible looking both up and down at the same time. Brilliant!
Source: http://blogs.nature.com/news/thegreatbeyond/2009/01/spooky_spookfish_has_freaky_ey.html http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VRT-4V719NP-5&_user=906544&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000047747&_version=1&_urlVersion=0&_userid=906544&md5=1fdce4ed93dd9abe54988c16448b1d9b
Bring back the basic
There's a irritating bug in the world of science administration and politics, growing stronger every day in every country formerly known as being capable producing various types of good science.
As you may or may not know, there's basically two ways of doing science. Most people working for companies and some working for universities and institutions produce applied science. This means that their experiments have a pre-defined goal, which is to yield information that can be used for something concrete (such as pharmaceuticals, pesticides, psychological information of how we behave in stores so that we can be tricked into shop even more, and so forth). This is relatively "easy" for the public to understand, and to get an opinion of.
Then there's fundamental science. Science that the public might have difficulties with, when trying to understand the purpose of it. It might produce some examples note-worthy to some popular science magazine or tv-show, but otherwise, if you're not in the academic world you probably won't get the deal about it. It is not necessary to understand why some fundamental research is important, BUT it is extremely important to understand why fundamental research is!
Think about the word "fundamental" for a minute, why it has been given this name. Wouldn't that give you a clue to why this is something that all science, including applied science is dependant of? Apparently, this has not gone through the minds of the politicians deciding how our countries tax money should be supplied to science. The companies manufacturing the drugs used to cure and help have not thought out all the background to their projects by themselves. It's fundamental. Without devoted ecologists (fundamental science) we would not have discovered the effects that various types of pollution have on flora and fauna, which also has led to restrictions protecting people from exposure to the nasty chemicals. Otherwise, this may not have been discovered until we saw a severe effect on the bodies and life of Homo sapiens. Without devoted molecular biologists (fundamental science), we would not have known all things we know today about DNA, proteins and various cellular actions. Then, a pharmacy would most likely not contain as efficiant pharmaceupticals that they do today. Are you starting to get the picture? All science is correlated, indepentant of national borders and other nonsense. And we need every single nieche, even though we may not see the importance of a particular result today. Cause we might see it in 20 years. And then it could be beautiful.
As you may or may not know, there's basically two ways of doing science. Most people working for companies and some working for universities and institutions produce applied science. This means that their experiments have a pre-defined goal, which is to yield information that can be used for something concrete (such as pharmaceuticals, pesticides, psychological information of how we behave in stores so that we can be tricked into shop even more, and so forth). This is relatively "easy" for the public to understand, and to get an opinion of.
Then there's fundamental science. Science that the public might have difficulties with, when trying to understand the purpose of it. It might produce some examples note-worthy to some popular science magazine or tv-show, but otherwise, if you're not in the academic world you probably won't get the deal about it. It is not necessary to understand why some fundamental research is important, BUT it is extremely important to understand why fundamental research is!
Think about the word "fundamental" for a minute, why it has been given this name. Wouldn't that give you a clue to why this is something that all science, including applied science is dependant of? Apparently, this has not gone through the minds of the politicians deciding how our countries tax money should be supplied to science. The companies manufacturing the drugs used to cure and help have not thought out all the background to their projects by themselves. It's fundamental. Without devoted ecologists (fundamental science) we would not have discovered the effects that various types of pollution have on flora and fauna, which also has led to restrictions protecting people from exposure to the nasty chemicals. Otherwise, this may not have been discovered until we saw a severe effect on the bodies and life of Homo sapiens. Without devoted molecular biologists (fundamental science), we would not have known all things we know today about DNA, proteins and various cellular actions. Then, a pharmacy would most likely not contain as efficiant pharmaceupticals that they do today. Are you starting to get the picture? All science is correlated, indepentant of national borders and other nonsense. And we need every single nieche, even though we may not see the importance of a particular result today. Cause we might see it in 20 years. And then it could be beautiful.
2009-01-12
2009-01-09
Before the dawn of life there was RNA
I suppose you've all heard about RNA; that it's related to the allmight DNA in one way or the other. What you might not know (if you're not into molecular evolution or just anything regarding evolution), is that once upon a time way back, before DNA started to function into something we define as life, there was another system of replicators highly dependent on RNA. Not much is known about this, but there's been some attempts to know more.
First, let's start with some basic RNA info (lots of chemical things here...skip if you're not interested or if it's just way too confusing). RNA stands for Ribo Nucleic Acid, and the only thing that differs it from a DNA (Deoxyribo Nucleic Acid) molecule is the presence of a hydroxyl group at one of the carbons. This, however, leads to differences in their chemical properties which is very, very important if we want life (as we know it) to exist. First of all, this changes the geometry (A-form instead of the general DNA B-form). Second of all, this -hydroxyl group can (if there's room) chemically attack a phosphodiester bond, so that the backbone of the RNA molecule is cleaved, as well as making RNA more prone to hydrolysis. RNA is usually present as shorter, single stranded chains of molecules, while DNA is usually in double stranded chains and is much longer. When you're not a molecular biology person, the most common thing to know about RNA (I suppose) is that it is the "in between state" when a gene is working. This is a basic rule of biology: DNA is transcribed into RNA that is translated into proteins. In addition, RNA can function as catalyst, acting in various ways. They do so by forming pairs, which are tightly and structurally packed with other pairs. Together, they can do powerful enzymatic activities. These properties have led scientists and general thinkers to hyothesize that RNA alone can function as both provider of information as well as the processor and
replicator of the information.
Gerald Joyce at the Scripps Research Institute in La Jolla, California have just published some amazing results on this stuff. She, along with collegues (you're never alone in this buisness) made catalyst of
paired RNA. When all the necessary ingredients were supplied in a reaction mix, these were able to assembly eachother. These were mixed with building blocks of RNA, and due to the RNA catalyst not being the perfect version for their purpose, they mutated over time into new versions that were better than the originals, thus out-competing them. The outcome was highly dependent on the conditions in the reaction mixture.
In addition, these RNA catalysts were immortal, since they could replicate themselves indefinitely! This is one of the basic properties a life-information-containing molecule must have...
In my biased little brain, this leads me towards the conclusion (not scientific, just highly personal) that once again, evolution can be induced, it's molecular action can be proven, as well as that Darwinian theory is supported again (and again and again and again ad absurdum....eat that, beloved creationists!). Also, all tabula rasa inspired folks should be somewhat joyful, since this also proves that the environment is just as important as the genetic material, when looking at the outcome of it all. It's just great!
Links: http://www.nature.com/news/2009/090108/full/news.2009.5.html
First, let's start with some basic RNA info (lots of chemical things here...skip if you're not interested or if it's just way too confusing). RNA stands for Ribo Nucleic Acid, and the only thing that differs it from a DNA (Deoxyribo Nucleic Acid) molecule is the presence of a hydroxyl group at one of the carbons. This, however, leads to differences in their chemical properties which is very, very important if we want life (as we know it) to exist. First of all, this changes the geometry (A-form instead of the general DNA B-form). Second of all, this -hydroxyl group can (if there's room) chemically attack a phosphodiester bond, so that the backbone of the RNA molecule is cleaved, as well as making RNA more prone to hydrolysis. RNA is usually present as shorter, single stranded chains of molecules, while DNA is usually in double stranded chains and is much longer. When you're not a molecular biology person, the most common thing to know about RNA (I suppose) is that it is the "in between state" when a gene is working. This is a basic rule of biology: DNA is transcribed into RNA that is translated into proteins. In addition, RNA can function as catalyst, acting in various ways. They do so by forming pairs, which are tightly and structurally packed with other pairs. Together, they can do powerful enzymatic activities. These properties have led scientists and general thinkers to hyothesize that RNA alone can function as both provider of information as well as the processor and
replicator of the information.
Image source: http://www.accessexcellence.org/RC/VL/GG/images/rna2.gif
Gerald Joyce at the Scripps Research Institute in La Jolla, California have just published some amazing results on this stuff. She, along with collegues (you're never alone in this buisness) made catalyst of
paired RNA. When all the necessary ingredients were supplied in a reaction mix, these were able to assembly eachother. These were mixed with building blocks of RNA, and due to the RNA catalyst not being the perfect version for their purpose, they mutated over time into new versions that were better than the originals, thus out-competing them. The outcome was highly dependent on the conditions in the reaction mixture.
In addition, these RNA catalysts were immortal, since they could replicate themselves indefinitely! This is one of the basic properties a life-information-containing molecule must have...
In my biased little brain, this leads me towards the conclusion (not scientific, just highly personal) that once again, evolution can be induced, it's molecular action can be proven, as well as that Darwinian theory is supported again (and again and again and again ad absurdum....eat that, beloved creationists!). Also, all tabula rasa inspired folks should be somewhat joyful, since this also proves that the environment is just as important as the genetic material, when looking at the outcome of it all. It's just great!
Links: http://www.nature.com/news/2009/090108/full/news.2009.5.html
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