Billions and billions of years ago I think that a large one celled plant/amimal ate a smaller one celled plant/animal and the little one didn't die. It in fact became part of the big cell adding more complex functions to it and maybe even its mitochondria. I think this because mitochondria has its own DNA and they divide independently from the main cell. I think this would make a great basis for a sci fi movie. A big space creature comes and eats us. We don't die but live inside the monster functioning independently from it but adding greatly to its own evolution, not to mention our own. It could be a happy, upbeat movie or a real disgusting, depressing one. Either way I would like to see it.

Mitochondria are the power plant in our cells converting candy bars into energy. Without them we would all have chronic fatigue syndrome. You get all your mitochondria from your mom because your dad uses all his up trying to power the tail of the sperm. I know, I don't like to think about my father's sperm either but this is us and it must be important. This alone makes a great case for a matrilineal system, doesn't it?

I think it further reflects the huge differences between males and females. Males use up all their energy on one thing and we never use ours up. This seems especially apparent in sexual reproduction because when they are finished, things just get going for us. This energy expenditure lasts for the next 30 years or so. Actually, as long as offspring are alive they constantly need something and it is our job to give it to them or feel guilty.

Tomorrow more about male/female difference and guaranteed to make someone upset.