I think it may be useful, at this point in the discussion, to construct a
chart relating the terms under discussion. Comments, anyone?
IDENTICAL
When two structures share common substructures,
those common substructures are said to be identical.
|
SIMILAR
|
Similarity is the degree to which two structures share
common substructures.
|
+---------------------+---------------------+
| |
HOMOLOGOUS ANALOGOUS
Similarity due to common Similarity due to convergent
ancestry evolution
|
+---------------------+
| |
ORTHOLOGOUS PARALOGOUS
Homologous structure with Homologous structure with
with conserved function divergent function
===============================================================================
Brian Fristensky | "The important thing is to develop the
Dept. of Plant Science | capacity to see one kernel that is differ-
University of Manitoba | ent, and make that understandable. If it
Winnipeg, MB R3T 2N2 CANADA | doesn't fit, there's a reason, and you find
frist at ccu.umanitoba.ca | out what it is."
Office phone: 204-474-6085 | Barbara McClintock, from A FEELING FOR THE
FAX: 204-275-5128 | ORGANISM by Evelyn Fox Keller
===============================================================================
