Sorry, there just happened to be a number of letters in common in polyamory and polymorphism, and I'm easily amused or confused.
Here's a start:
Etymology: From Ancient Greek poly (many) + morph (form) + -ism.
The ability to assume different forms or shapes.
- (crystallography) The ability of a solid material to exist in more than one form or crystal structure; pleomorphism.
- (biology) The coexistence, in the same locality, of two or more distinct forms independent of sex, not connected by intermediate gradations, but produced from common parents.
- (computer science) The feature of object-oriented programming pertaining to the dynamic treatment of data elements based on their type, allowing for an instance of a method to have several definitions.
One of the most important types of polymorphism in biology is
single-nucleotide polymorphism (SNP, pronounced "snip".)
Geneticists often speak of replacing a snip of DNA. A snip of DNA is just a tiny little piece of the genome making one string of DNA different from another. In fact, the difference is just a single nucleotide — A, T, C, or G — in the genome. That one little difference might have very significant consequences, for example whether you are resistant or succeptible to a certain disease.
I had the computer science definition in mind.
If you want your mind to go numb, you can read
http://en.wikipedia.org/wiki/Polymorphism_in_object-oriented_programming but the general concept is that things, which we call
types, can have
many forms or
subtypes, and each subtype can respond differently to the same command.
The simple example is that
cat and
dog are each subtypes of
animal. If you issue the instruction (which we call a method)
speak, the cat will say "Meow" while the dog will say "Woof!"
