Wednesday 13 September 2006

Life


I almost gave up to write today. I'm having problems with Blogger and everytime I try to login the browser window simply closes. I had to do a lot of gymnastics to be able to get here today!

Well, to be honest, I didn't know exactly what to write until I started to read the science news. Then, I stumbled with this one:

Why viral stowaways are a baby’s best friend

This news talks about something called endogenous retroviruses (ERV). They are remnants of virus DNA which attached to our DNA in some point of our evolution and remains there even today. I remember that sometime ago I read about the fact that ERVs are responsible for the growth of the placenta, which is the main subject of the above news.

Probably, there are a lot of other ERVs in our DNA which somehow gave us some advantage and remain there executing important functions. This added to the fact that bacteria play a major role in our digestion and that our energy comes from processes taking place in the mitochondria, which are a kind of alien organism which lives in symbiotic relationship with us, even with his own DNA different from ours, implies that we are not only one organism, as we feel to be. We, indeed, seem to be a colony much alike an ant conlony, but where the components are not allowed to take a walk outside and then come back.

Thinking about that, it is amazing how complex a life form can be. Another amazing news somehow related which I read recently, and unfortunately lost the link :( , was about a kind of cancer which affect dogs and is contagious. I was amazed when a read the origin of this disease: it is not a bacteria or a virus, it is a group of tumorous cells from an ancient dog or wolf which can be passed from animal to animal and replicate themselves inside it. In a way, the animal which was the original owner of the cells is around and will be around probably forever in the form of cloned cells carried by host animals! Now, is it an organism or not?

Seeing how creative and unimaginably complex Nature can be with respect to life, I can only smile when I see aliens in sci-fi movies with almost the same form as us. I bet that when we finally make contact with other technological species from another planet it will be something that we have never imagined before.

Picture: Mouse osteoblast, from the University of Western Ontario website.

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