Star Wars FORCE

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Mitochondrial Tours Episode II: No Lack of the Groans

Elaborating on CL’s explanation of maternal inheritance of mitochondria… in sexual species males and females are distinguished by whether they produce sperm or eggs (respectively). Sperm are simple 'vehicles' that only contribute to the next generation of organisms via the DNA in their nuclei, in contrast with eggs which are the basic 'home' for the male DNA delivered by the sperm. Mitochondria are located in the female cell cytoplasm, and so because sperm only transfer their nucleus/DNA, mitochondria can only be inherited from the mother.

A more important implication than the ‘eve theory’ for dissimilar gametes (sex cells) is that it forms the fundamental basis for the differences between the sexes, ranging from 'dimorphism' (differences in appearance) to behaviour. For males DNA-transporting sperm are 'cheap' to produce, while females need to make (e.g.) the cytoplasm and everything it contains. In effect, females 'invest' more in their offspring. For example- once offspring have been born, fathers are far more likely to abandon their kids than mothers, as they have given less to the relationship in terms of actual material, energy, time, etc. This relationship is ‘self-reinforcing’, with females being less successful in ‘bluffing’ their way out of childcare after birth (as the fathers know that the mothers have invested more than they have and so are less likely to abandon their gene-carrying progeny). Females then become increasingly/progressively burdened with providing the majority of the offspring’s requirements, leading to (eg.) gestation (female pregnancy).

As Forashi correctly remembers, the DNA of mitochondria (and their bacterial ancestors) has a different 'architecture' in the way that the different genes are arranged on the genome. Mitochondrial genomes (the entire complement of genes an organism/virus possesses) differ from bacterial ones by being more 'streamlined' genetically. For example, consider a gene that ‘encodes’ (provides the instructions to make) a protein that copies DNA within the cell. If there is a gene in the mitochondria which is ‘functionally similar’ (does the same thing), then that gene is a ‘waste of space’ from the perspective of natural selection. The mitochondria could import (from the cytoplasm) the protein involved in copying the DNA. It is usually the mitochondrial copy of the ‘similar’ gene that is lost. The result of this is that after billions of years of association, mitochondria have become dependant on their host cells for life, and are no longer able to ‘escape' as free-living bacteria.

If we relate this intimate (host cell/mitochondria) relationship back to the Star Wars universe, we could use an analogy whereby ‘the force’ is the product (protein) of a gene that the mitochondria is no longer able to make (midichlorians acting as the ‘receptors’ Nobleman described). In return, midichlorians would provide ‘energy’ to their hosts (lots in Anakin!). A ‘positive feedback loop’ could operate- more midichlorians would equal more ‘receptiveness’ to the force, which means more ‘energy’ (also possibly the force) enabling the host cells to be more successful/productive, resulting in more force!

[Forashi- i doubt you have free access to online scientific journals, so i've sent you an essay that i wrote on the origin of eukaryotes, which includes a large section on the origin of mitochondria (i got an ‘A’ for it, though the lecturer said the style of writing was ‘too emotive!’ CL!) and a recent pdf review article (though i think it's written in an unnecessarily overly-complicated manner). if you have any more questions, don't hesitate to ask.]

[Nobleman- i liked your force-midichlorian idea, and so unashamedly thieved it. doubt there was anything wrong with theforce.net author’s sources, more likely his interpretation]

[british citizens- don’t forget the box on the next national census!)

see, see- i can use the shift key (but i won’t make a habit of it)! (this is the first time i’ve bothered to write an essay for the boards, so you may now refer to me as… BigB-2!)

science is the path to the dark side… science leads to knowledge… knowledge leads to power… power leads to suffering!

 

Nice to see an educated man out there. =D Well t'was a fulfilling explanation at least. Too bad I'm not that well versed in the arts of biology, interesting as it is. Thanks.

 

I have to note that I personally believe in the Force to some extent, and Lucas can stuff midichlorians back up his arse.

Ara
(Duct tape is what keeps the world in one piece...)