Transitive homology

This page explores the transitive closure of the homologous_to relation. Currently in OBD this is a binary class-level relation that holds between two taxon-specific anatomical entities.

I propose the following expansion to OWL-DL instance-level quantified axioms:

 homologous_to(A,B) ==>
 Class: A
 SubClassOf: descendedFrom some (hasDescendant some B)
 Class: B
 SubClassOf: descendedFrom some (hasDescendant some A)

If we make the simplifying assumption that directlyDescendsFrom is functional then it follows that class-level homology is transitive. What are the consequences of making this strong assumption? We can explore this with existing phenoscape data.

TAO classes with homology statements

from latest KB:

ID	name	Def
TAO:0000429	scaphium	Neural arch and Weberian ossicle that is reduced in size relative to other neural arches. Scaphium has a process which articulates with the first centrum.
TAO:0000525	intercalarium	Neural arch and Weberian ossicle that has been modified in shape relative to other neural arches. Intercalarium includes three parts: an anterolateral process (the manubrium) which is embedded in the interossicular ligament and the ascending and articulating processes.
TAO:0000637	claustrum cartilage	Postcranial axial cartilage and Weberian ossicle that is located dorsal to the scaphium. The claustrum cartilage is bilaterally paired.
TAO:0000698	tripus	Endochondral bone, membrane bone, and Weberian ossicle that is an element of third vertebra. Anteriorly it attaches to the interosseus ligament and posteriorly it extends as a transformator process embedded in the tunica externa of the swimbladder.
TAO:0001171	os suspensorium	Endochondral bone and Weberian ossicle that is an element of the fourth vertebra that curves ventrally around the anterior head of the swim bladder.
TAO:0001253	neural arch 2	Neural arch that is the second after the neurocranium.
TAO:0001335	supradorsal	Supradorsals are small paired nodules of cartilage positioned at the distal ends of neural arches and the proximal end of neural spines (Arratia et al., 2001).
TAO:0001396	parapophysis + rib of vertebra 4	The parapophysis + rib, fused to the centrum, extends laterally then angles anteroventrally. A thin plate, the os suspensorium fuses to its median surface.
TAO:0001592	claustrum bone	Endochondral bone, membrane bone, and Weberian ossicle that is located dorsal to the scaphium. The claustrum bone is bilaterally paired.
TAO:0001877	neural arch 1	Neural arch that is the anteriormost neural arch.
TAO:0001878	rib of vertebra 2	Rib that articulates with the parapophysis of the second centrum.
TAO:0001884	accessory neural arch	Neural arch that is located posterior to the neurocranium and anterior to neural arch 1. The accessory neural arch is not associated with a vertebral centrum.
TAO:0001885	neural spine 1	Neural spine that is associated with the first vertebra.
TAO:0001888	supraneural 1 bone	Supraneural bone located dorsal to vertebra 1.
TAO:0001889	supraneural 1 cartilage	Postcranial axial cartilage located dorsal to vertebra 1.

High Level Overview

This is a high level part_of view of all homology relationships, projected onto TAO:

Error creating thumbnail: Unable to save thumbnail to destination

• homology statements are generalized to the TAO, taxa not shown
• clusters of homology relationships are shown in 4 distinct boxes
• vertebra clustered into a box
• only relations shown are homology and part_of

Here we can see there are 4 distinct clusters, according to the vertebra number affected

Otophysi intercalarium

this is annotated to be homologous to the neural arch 2 and vertebra 2 in Teleosti. From this, what can be said of the relationship between these two entities?

Error creating thumbnail: Unable to save thumbnail to destination

Note that for compactness reasons this diagram doesn't show the part_of relations.

• intercalarium part_of v2

presumably there should be some kind of relationship between "rib of v2" and "v2"

Otophysi tripus

this is annotated to be homologous to (i) the fusion of parapophysis + rib of v3 and (ii) the fusion of parapophysis + rib of v3 + rib of v4 in Teleosti. What can be said from this of the relation between (i) and (ii)

Error creating thumbnail: Unable to save thumbnail to destination