stubighead

Yes, of course if handedness is genetic, i dont know about that and a neurological factor seems more likely, left handedness doesnt have to have an advantage to exist in a population just so long as it isnt a disadvantage in reproducing. It would be just another variation in the human species. This of course is a fundamental principle of evolution, variation must exist to allow evolution to move in any particular direction if need be. There are humans with plenty of movement in their toes but i think this is generally a good thing for those wishing to swing through trees ie. monkeys!! Humans are humans cos it was an advantage to lose that ability and replace it with feet better for walking and running than gripping tree branches. Yes, evolution allows variation to occur so long as it is not detrimental to the organisms ability to reproduce. If this wasnt the case natural selection would have nothing to work on.

Oh and yeah britain is a bit obese although it is widely excepted that america is the fattest nation on earth - sorry.

I think there is little chance of us being wiped out anytime soon. Really the only likely thing to do that would be a big enough asteroid to come out of the blue capable of wiping most of us out and then leaving the planet in an uninhabitable state, all be it temporary. If we had enough warning it would be possible to construct a reserve where a small population could survive until the planet was able to support us again. A virus would be unlikely to wipe us out simply because there is enough variation in the population to ensure some individuals would be immune. As far as the future of the human race goes, well evolution occurs over a very long time and requires selective pressures of which there are few. I think one interesting idea is that the population could eventually ie a long time, split into two species different in intelligence and attractiveness. This is a genuine selective pressure as mentioned before. It wouldnt result in less attractive and less intelligent people going extinct i doubt because firstly if this was going to happen it probably already would have as this would have been a very early evolutionary change, secondly, through the population there is a very wide range of intelligence and attractiveness so there must be equal successfulness for all individuals. This is could be due to less attractive and less intelligent people reproducing together and vice versa. This forms a social split in a population. If you run this over a few thousand or million years you could have two seperate species formed. Of course on the other hand the more intelligent species may decide for some reason that it is not a "good thing" to have this other lesser species in existence and drive them to extinction in some humane manner (or not and just wipe them out). After all this is what happened in theory when humans evolved in the first place. The more intelligent individuals proved more succesfull and consequently took over the world replacing (not living alongside) our ancestors. It is not unreasonable to think this could happen again. ill take a breath.

I can tell you that photons can interact with electrons and may result in the production of further photons. The original photon may or may not be completely absorbed and may just be deflected off its course. Its all about transfer of energy. So if the photons you are talking about have to pass through matter on their way to us then they may not be the original photons produced by whatever. However many will be as a photon is very small and can easily pass through matter without interacting at all. (think x-rays taken in a hospital, the xrays (photons) have to pass straight through the patient without any interaction to produce a good picture. In this case any xrays deflected or absorbed or created by interaction can result in picture degradation due to them not being original xrays or being off original course. Im not a cosmologist but those are the basic interactions of photons with matter - complete absorption by an electron or nucleus, or deflection by an electron. Either can result in a new photon being created. stu