maandag 24 maart 2014

Can Invisibility Evolve?

A reflection on the possible evolution of invisibility

When I was listening to the song Invisible Kid by Metallica in the car, a question popped up: Can real invisibility evolve? And I am not talking about camouflage or an invisibility cloack à la Harry Potter. No, I am thinking about real invisibility: there is nothing to see, but still something is there... (actually sounds a bit scary)

The benefits of pure invisibility are quite obvious. Predators can easily hunt for prey, they don't have to sneak up to them or wait patiently for hours in an ambush. For prey species, the same goes to other way. They don't have to worry about being seen by predators.

But for invisibility to evolve, individuals with this trait need to reproduce. Depending on the mating system, invisibility can be beneficial or a serious problem. For example, some fish species have smalle sneaky males that quickly deposit their sperm while two other fish are getting it on (well, they just spray eggs and sperm into the water). If these males are invisible, they would be more successful.
However, species that actively look for a mate can be faced with some challenges. How can you find something that you cannot see? Sound, smell, or certain cues might be helpful.

A big normal male and a small sneaky one.
There are off course some animals that have evolved a kind of invisibility, by becoming transparant. But pure invisibility has never been observed, which is actually quite logical. I am not sure whether purely invisible organisms can arise by natural selection. Or they have and we just haven't found them yet...

A transparant fish

maandag 17 maart 2014

The Belgian Lichen

A reflection on symbiosis and Belgium

As a Belgian citizen it is always difficult to explain the structure of my country to foreigners. A friend nicely illustrated the confusion with regard to languages:

"In France they speak French. In Germany they speak German. So in Belgium, you speak Belgian?"

Well, not exactly... Belgium has three official languages: Dutch, French and German. For quick overview of Belgium state, I refer to Wikipedia and the following movie:

[...] a unique form of a federal state with segregated political power into three levels:
1. The federal government
2. Three language communities

  • The Flemish Community 
  • The French Community
  • The German-speaking Community
3. Three regions

  • The Flemish Region (five provinces)
  • The Wallon Region (five provinces)
  • The Brussels-Capital Region

The tension between the Dutch- and the French-speaking community has been around since the start of Belgium in 1830. Recently, several political parties, such as Vlaams Belang and NVA, are openly advocating the splitting of Belgium. 

The structure and history of Belgium reminded me of a natural phenomenon, the lichen. This is a composite organism consisting of a fungus and an algal or cyanobacterial partner growing together in symbiosis. At first sight, these organisms have nothing in common, but they manage to thrive together. Research has shown that the symbionts can survive separately, but they do not enjoy the same survival success in extreme environments. 
Whether this principle holds for Belgium? We might find out in the near future...