Morphostasis: an evolving perspective
This page gives a brief synopsis of this article – published in 1996
"Morphostasis: an evolving perspective" – 1997.
Synopsis and main points
- This article looks in more detail at the probable evolution of morphostasis
- It emphasises the concept of tautologies (self evident "truths") that, nevertheless need to be stamped out because we tend to agree to them just before proceeding to ignore them.
- Other–than–healthy–self is defined further
- The evolutionary shell concept is emphasised – "~ ~ each (evolutionary) step is an embellishment of a former step, and all remain functional in mammal morphostasis. Each is a new "shell" which is superimposed over and is complementary to the former shell. It is important to note the fundamental centrality and importance of this structure. Shells are built upon – they are neither abandoned nor substituted but remain fully functional."
- It now takes a conjectural romp through:-
- The "self" cell which is (defensively) delimited by the cell membrane
- The evolution of internal (cell) surveillance
- The evolution of apoptosis
- The evolution of gap junctions
- The evolution of cell adhesion molecules
- The concept of "soma"/"scavenger" segregation
- The importance of gap junctional communication in establishing an "I'm not worth checking" identity.
- The evolution of natural killer cells, cytotoxic T–cells, helper T–cells, B–cells and free antibodies.
- The likelihood that gap junctions are important contributors in immune cell interactions
- It concludes:–
- "I have explored the probable evolution of morphostasis and conclude that gap junctions (GJs – plasmodesmata in plants) are the cornerstone of metazoan success. While many of the component ideas are speculative, I believe the general theme is crystal clear. The more precise deductions will inevitably require revision. It emphasises the proportions that should be attributed to each part of the system. In particular, it suggests that more investigative effort should be concentrated on GJ physiology. I propose that this hypothesis may provide a useful framework on which to hang a more focused investigation of the biochemical processes of morphostasis."
- I have made a number of guesses about the sequence of the evolvution of various immune system componenets: some of these need modification. In particular, the evolution of perforin and C9 may be earlier than suggested. The evolution of B-cells (effectively, macrophages targeted at material displaying particular epitopes) may have evolved as developmental processes that help resorb particular cellular debris (an example would be finger webs).