Posts Tagged ‘war’

Exploring the blurry line between colony and individual

// August 3rd, 2011 // 1 Comment » // The Realm of Bizzare

I found this great post on the Portuguese man-o-war, known as the bluebottle in Australia, over at Deep Sea News the other day. It’s eating a fish!

The post also said:

Remember this species is colonial and made of four different polyps or zooids, working in unison and dividing labor. The bladder is a single polyp called a pneumatophore. The long tentacles are dactylzooids used for fishing. The dactylzooids bring the fish up to another set of zooids, gastrozooids, responsible for digestion. Last, there is set of zooids, gonozooids, in charge of reproduction.

So it looks like a jellyfish, but it ain’t. It’s a colony of four specialists working together, each with their own nervous system but incapable of living by themselves.

Bluebottle on Woolongong Beach, NSW. Image by Fiona Wilkinson

As I was doing a bit of research about bluebottles and how they sting even when dead and dried up, I came across an interesting question. How do they reproduce? If the gonozooids are responsible for getting jiggy with it, don’t they just make more gonozooids? Where do the rest of the polyps come from?

Well, no one really is a hundred percent sure. I guess that’s fair enough, studying a swarm (a navy) of man-o-wars during mating season doesn’t sound too good. But here’s what they think.

A gonozooid from one man-o-war will make sperm which combines with an egg from another man-o-war gonozooid. Hey presto, you’ve got fertilisation and one embryo – which will become the bladder polyp at the top. That embryo divides several times, then reproduces asexually to make more zooids, which bud out of it. The budding polyps will become either tentacle, digestion or reproduction individuals.

That’s where I got confused. Does this mean that each of the zooids actually come from a single polyp? Are they just differentiated forms of the original polyp, specialised for their particular role? How is this different to a human embryo producing heart cells?

One explanation uses phylogenetics – comparing organisms to see how similar and different they are. Each zooid is similar to solitary Cnidaria (the phylum that includes jellyfish, coral and bluebottles), so can be considered an individual in its own right and a bluebottle as a colony.

But if we define an individual as something with similarity to other individuals, then all the cells of a multicellular organism would be individuals. Are individual humans really colonies of individual human cells? Really, the microbes on and in you outnumber your human cells 10 to one, so you’re more like a walking microbial factory anyway.

White poplars, a kind of aspen, form clonal colonies. Image by Jacob Halun

I think we have a very human-centric model for defining individuals, which is not surprising really. But most species on the planet don’t reproduce like we do, the boundaries between individual and colony are much less clear.

Take aspen trees, which can grow by seeds (sexually) or by underground runners which sprout a tree-clone (asexually.) Over time the runners can decay separating the trees. How can we tell if the trees are individuals or clones, and if we can’t, how do we study adaptation and natural selection?

Tasmania has these Huon pines that are the oldest genetically identical stand of trees which has lasted 10,000 years. Each tree lives about 2,000 years, but the original tree renews itself through genetic clones. Tassie also has the oldest genetically identical plants, clones of King’s lomatia estimated to be at least 43,000 years old.

Strawberries do it too, as do fungus. A single specimen of Armillaria solidepes was found in Oregon the size of 1,220 football pitches and estimated at 2,400 years old. It’s one of the largest organisms in the world.

Where does the individual end and a colony begin? Looking at all the bizarre stuff out there, I can’t help but wonder if we’re the weird ones.

ResearchBlogging.org

Clarke, E. (2010). The Problem of Biological Individuality Biological Theory, 5 (4), 312-325 DOI: 10.1162/BIOT_a_00068

Read it at the homepage of Ellen Clarke

How aqua regia saved Nobel Prize medals from the Nazis

// October 25th, 2010 // 12 Comments » // The Realm of Bizzare

Aqua RegiaIt was a brisk April morning in 1940, and George was in a fix. In his hands were two Nobel Prizes illegally smuggled from Germany, while outside the lab Nazi’s swarmed the streets of Copenhagen. Denmark was now occupied by the Germans, and it was only a matter of time before they entered the Institute of Theoretical Physics and searched the building.

The medals belonged to Max von Laue and James Franck, Germans who had won Nobel Prizes in Physics some years ago. Their names where on the medals, and taking gold out of Germany was almost a capital offense, carrying a punishment not to be sneezed at. George was certainly not sneezing, but his palms were sweating as if he had a fever and his heart was pounding like a drum. There might be only hours until Nazis found the medals, and his neck would certainly be on the chopping block along with theirs.

What to do? Hide it in a hollowed out book as children hide sweets? No, there was no guarantee the books would stay put, they could be sent away or burned for all he knew. Bury it then? There simply wasn’t time, a freshly dug grave would only attract attention. No, it had to be changed, made unrecognisable, hidden in plain sight. Somehow. Think George, think. To every problem there must be a solution. Keep at it until a solution appears.

A solution! Of course! The gold should be hidden in solution! To wait out the war in a nondescript bottle sitting on a shelf. The worst that would happen is it would be thrown away, and if that was to be at least there would be no tell-tale engravings to point fingers.

George looked around the lab for the ingredients to a potent cocktail. Only one thing would dissolve gold. Aqua regia, a mix of three parts hydrochloric acid to one part nitric acid. Alone neither of these acids could change gold, very few things could. Gold was considered such a rare and beautiful metal for exactly that reason, because it was unchangeable and very stable. It would not rust like iron or turn green like copper. Strong, concentrated acids would not burn a hole in gold as they would other metals. Unless of course that acid was aqua regia, royal water.

In a large flask George combined the two acids quickly, his hands now dry and mind focused. The resulting mixture was colourless for an instant before turning faintly peach and then bright orange. With one held breath he dropped in the two gold medals.

Chemistry had always attracted George de Hevesy since he had first worked on radioactive isotopes thirty years ago. His work on them had uncovered many mysteries of biology, such as what part of a growing plant captures poisonous lead to protect the rest of the plant (the roots.) He was still a mover and shaker in the field, which was growing rapidly and had even entered the realm of human experimentation. If a man was injected with a radioactive isotope, where did it go, how long did it stay there and how was it excreted?

He was, in certain circles, quite famous. Perhaps in the near future he would be holding a Nobel Prize of his own.

But for now, these two Prizes were all he had, and they were getting smaller. The magic of aqua regia was in the way the two acids worked together.

Nitric acid had the power to take small amounts of solid gold and put it into solution. On its own it wouldn’t make any difference at all, because it would only allow a tiny amount of gold to be in solution at a time, with the gold being in equilibrium between solid and soluble form.

Hydrochloric acid, on the other hand, could supply its chloride atoms to convert gold to chloroaurate. But by itself it did nothing because it couldn’t get a grip on the gold to start with.

In aqua regia, the gold was put into solution by the nitric acid, and then converted to chloroaurate by hydrochloric acid. It pushed the equilibrium across, allowing the nitric acid to pull more and more gold into solution, where it was quickly changed into another form.

Once the reaction was complete, George sealed the flask and put it high up on the shelf. There it would stay until the war was over, and perhaps in brighter years he would return and extract the gold out of the solution, and return it to the Nobel Foundation where it could be recoined and returned. If brighter days ever arrived.

——

This be fiction based on a true story. George de Hevesy is credited with dissolving two Nobel Prizes in aqua regia and storing them during the second world war, where they remained unnoticed despite careful searching by the Nazis. The gold was later recovered and recoined, and presented back to the two owners. George de Hevesy won the 1943 Nobel Prize in Chemistry for his work on radioactive isotopes.






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