Australian Bioscience News & Views

Life is parasitic

Genes and memes are selfish replicators, and the very convoluted nature of it all is highlighted nicely by the example of how the "green things" were assimilated. I don't mean "little green men", I mean how plants and algae got their chloroplasts. Chloroplasts are the tiny, membraneous balls within the cells of photosynthesising organisms that do the actual work of converting sunlight to chemical energy.

On several different occasions, larger cells "trapped and enslaved" these tiny sunlight-powered workhorses and put them to use feeding larger and larger structures.

This view of life is an interesting, almost negative take on The Goldilocks Enigma proposed by Paul Davies. On the other hand, it might be more apt to consider the example of one type of cell engulfing another as a kind of ultimate example of natural selection resulting in novel solutions to the basic problems of life, such as the need for energy.

Sugars from different angles

I've known a few people with type I diabetes, a few more with type II, and have often wondered when the new molecular and genetic research would have pay offs for them. It's not an entirely altruistic impatience, as there is some type II diabetes in the family history.

Recent reading has been rewarding on the diabetes front. Researchers from University of Tokyo have found that there are genes coding for mechanisms for increasing the number of beta cells, and the amounts of insulin they secrete. Thinking in terms of diabetes, it's easy to assume sugar is all bad, but there is a good side to it. A particular complex sugar to be found in many cells and secreted by the liver, can reduce the amount of fat in the blood.  Undertaking some research in mice, a US team found that the presence of this sugar called heparan sulfate, in the liver, increases the clearance of triglycerides and cholesterol from the blood. Both these new pieces of research look like pretty good candidates for new treatments designed from this knowledge.

It would be interesting to see what insights The Evolution Of Human Diet might provide. I'll see if a copy can be tracked down.