Private property is the right to obtain, own, control, employ, dispose of, and bequeath property. An owner of property can consume, sell, rent, transfer, exchange or destroy her property, excluding the others from the decision concerning this property. One's own body is an example of property (Locke). A man may be in need for a kidney transplant, but this person cannot harvest your kidney without your permission. At least, we are not at this point yet, though I do not see why "debt to society" cannot be extended to such arrangements. One can retort, of course, that removal of a kidney will harm you regardless of the purported benefit to the others. The harm argument does not apply to hair. Can another person cut your hair to address the injustice of having a bald spot? The concept of ownership is that (with a handful of exceptions, such as the Lockean proviso) there is no need that is great enough to force you to part with your property, be it kidney, hair, a prosthetic leg, or anything else which is yours. Having private property is a natural right that needs no justification.
If property rights are natural, were are such rights in nature? Starting with the basics: do isogenic bacteria "own" something individually? I argue they do. Magnetotactic bacteria import iron(III) from the environment and mineralize magnetite in vesicles lined with proteins shaping the growing crystal. This is the only example of internalized biomineralization in the prokaryotes.
...Magnetosome chains are organelles contain 15 to 20 magnetite crystals. Each crystal is surrounded by a lipid bilayer, and specific soluble and transmembrane proteins are sorted to the membrane. The crystals have high chemical purity, narrow size ranges, species-specific morphologies and exhibit specific arrangements within the cell. The particle morphology varies, but is consistent within cells of a single magnetotactic bacterial species or strain. Magnetosome crystals are typically 35-120 nm long and arranged in one or more chains. The magnetic dipole moment of the cell is large enough such that its interaction with Earth's magnetic field overcomes random forces.
http://en.wikipedia.org/wiki/Magnetotactic_bacteriahttp://www.calpoly.edu/~rfrankel/NatRevMicro.pdf The magnetosomes are like hair: a bacterium can survive without the magnetosomes, but the magnetosomes give it advantage. Some bacteria can have many more magnetosomes than they need for magnetotaxis. The analogy would be having 250x more bone than needed for standing up. Hoarding magnetite chains can be used to form a cytoskeleton: mineral wealth does pay off.
...There are examples of magnetotactic bacteria that contain hundreds of magnetosomes, many more than required for orientation. M. bavaricum, contains up to 1000 magnetosomes forming 3-5 rope-shaped bundles arranged such that they are separated by the maximum possible distance from each other and positioned adjacent to the cell envelope. Repulsion forces between parallel magnetic dipoles drive the chains apart from each other and forcing them to be in direct mechanical contact to the cell envelope. Thus, the magnetic torque acting on the chains under the influence of the geomagnetic field can be transferred very effectively to the whole body. It is also a means of achieving a magnetic moment large enough for a given cell size to overcome the viscous resistance with respect to the surrounding medium, which is required to ensure an alignment with the geomagnetic field as fast as possible. doi:10.1016/S0012-821X(96)00191-4
The magnetosomes of a mother cell are shared with the daughter cell, as inheritance: the division occurs cleaving the chain in two.
http://www.ncbi.nlm.nih.gov/pubmed/20473965 Other bacteria mineralize, but the mineralization is extracellular. E.g., calcium carbonate crystals might be grown in a bacterial film attaching the cells to a surface. This film is the communal property. Magnetite crystals are private property that is not shared with anyone but daughter cells. About other biomolecules one can argue that these are the communal property (the genes are shared and all molecules produced by the cellular machinery are alike). No two magnetite crystals are alike and there are no magnetite genes. Some bacteria produce these crystals in excess of necessity (magnetotaxis) while their kin are starving for iron. The bacteria do not share their magnetite regardless of the social benefit of such sharing.
This does not mean they are asocial. Some magnetotactic bacteria are committed individualists, but some live in a colony and do not occur individually.
http://www.im.microbios.org/0904/0904267.pdfThe cells in the colony are connected by calcium, which is communal. Their magnetite is private. Private is private and communal is communal.
Is the right of the bacterium for its magnetite natural? It is natural in the most natural sense: bacteria do not have the means of internalizing large, rigid particles. The property rights are protected by nature: only one process - cell division - can result in the transfer of magnetite from one bacterium to another. One can object that magnetite is part of the bacterial body. The same can be claimed about gold coins hidden from the Sheriff of Nottingham in the anal cavity of an English peasant. Furthermore, to Locke, one's body is one's property. Another objection is that bacteria cannot transfer property rights, lease, or rent. True, but my ideas remain my property even if I have no means of communicating these ideas to the others. The important thing is that other bacteria have no control over one's decisions concerning the use of the magnetite regardless of the potential benefit to themselves and this lack of control is natural. Bacteria can share a lot of things, but they cannot share magnetite. When a cell dies, the crystals are dissolved, the iron is imported by other bacteria, and they begin their own quest for accumulation of wealth. QED.
Locke, Hume, Rousseau, Kant had their make-belief geneology of property rights,
http://plato.stanford.edu/entries/property/#4and here you have it in a drop of water...