Proposed edits to the 'displaced' branch.

[dosumis]

1. There is no obvious difference between the definitions of mislocalised and displaced. Neither of these terms refers to 'develops in the wrong location', although this would be a really useful thing to record - distinct from dislocated (develops in correct location and then physically moves).
2. It would be useful to have a grouping term covering 'develops in the wrong location' and
3. Ectopic is a bit more specific than 'develops in the wrong place' - it is generally not used for cases where there is a general shift in overall pattern - something which fits well with the various subclasses of mislocalized (e.g. mislocalized anteriorly), but is used for development of some structure in a place it doesn't normally develop, typically (although perhaps not always) in addition to the existing structure. e.g. eyeless expression in a fly leg can induce ectopic eye development. Ectopic wing veins are vein structures appearing in regions that are normally inter-vein. In contrast, changes in pattern specification that move many stuctures are not normally referred to as generating ectopic structures - e.g dorsalization of a Drosophila embryo moves all epidermal pattern elements dorsally (sometimes eliminating ventral pattern elements).

Proposal (leaving some terms without names):
X: A positional quality inhering in a bearer by virtue of the bearer's being out of its usual or proper place, or position.
. . is_a Y: A positional quality inhering in a bearer by virtue of the bearer's being out of its usual or proper place, or position due to development in that position.
. . . is_a ectopic: A positional quality inhering in a bearer by virtue of the bearer's being out of its usual or proper place, or position due to development in that position, excluding cases where this is due to a general shift in pattern specification that moves many pattern elements in a co-ordinated way (e.g. dorsalisation of a fly cuticle).
. . is_a dislocated: A positional quality inhering in a bearer by virtue of the bearer's being out of its usual or proper place, or position due to it being physically moved from the normal location.

TBD:

• Is the distinction for ectopic too confusing?
• What terms do we use for X and Y? Could mislocalised by used for developing in the wrong place or is that too confusing?

More info needed:

Usage examples for misocalised, displaced and position.