Analagies
Sloppiness and precision- AK-47 versus sniper rifle
Assault rifles were developed in World War 2 with the first widely used model the German ST44. It was realized that the currently used battle rifle was ill-suited for the modern battlefield, particularly in urban environments. Accuracy at long distances was not really important, considering the reluctance of soldiers to expose themselves long enough to aim well in the face of returning automatic weapons fire. The design changes included shortening the barrel, using a shorter cartridge and bullet and a stamped steel receiver, with provision for semi-automatic and automatic fire. The receiver is the housing that holds the chamber and barrel and coordinates the moving parts: injector, bolt, firing mechanism, and extractor. Previously, the complicated structure of the receiver required milling from a solid piece of steel. In stamping, sheet steel is pressed and folded into a complicated shape. Instead of the receiver providing surfaces that hold the bolt in place against the explosive force, these are provided by a separate part, the trunnion, which is riveted to the receiver. The less sturdy structure produces more vibration which lessens accuracy, but that was never the goal.
The reduction in weight of the rifle and ammunition meant more rounds could be carried. The assault rifle also had more fire power than submachine guns, which use smaller pistol cartridges.
Kalashnikov's AK-47 was the Soviet version of the assault rifle. Because their stamping technology was not as good as the Germans', it was built to looser tolerances, which further decreased the accuracy. This "sloppiness" turned out to be a blessing in disguise. It seldom jammed or misfired in extremes of temperatures, damage, dirt, rust, or poorly manufactured ammunition and magazines. As a result, the modern AK-47 is not all that different from the original and has become the weapon of choice of poorly trained irregular fighters around the world.
I think ectotherms are in several ways analogous to the AK-47. Homeotherms are like modern sniper rifles. They incorporate innovations that would be wasted or impossible if applied to the AK-47, but which require much more precise manufacturing and operational conditions for successful performance. Both require a narrow temperature range. Even the heat from a single round may degrade the accuracy of the next.
Overall Hypothesis- Multiple Critical Paths
When I first joined the army, my first assignment was to the Engineer Officer Basic Course. Besides military topics, we received training in construction for building roads, bridges, fortifications, etc. One topic was the critical path methodology for project planning.
The first step was to list all the components (materials, personnel, equipment, etc.) needed to be procured and specific tasks to be performed. An initial plan would then take shape as a diagram with arrows meeting or diverging at vertices. Arrows away from vertices would represent tasks that could not be started until all the tasks represented by the incoming arrows were completed. Each task might further be broken down into a diagram of its own.
The critical path for a project was the sequence of tasks which if any were delayed would delay completion of the project and which would require the most attention. The method also supplied estimates for other (non-critical) paths of how long they could be delayed before they become part of a new critical path.
I never had to plan any construction, However, while never actually drawing a critical path diagram, keeping its principles in mind was useful in carrying out complicated work.
I was later assigned to a combat engineer battalion in Korea where construction was the majority of the mission. Limited facilities meant little indoor prefabrication was possible. Adverse weather, from summer monsoons or winter snowstorms, and wide annual temperature variation meant that tasks never went as planned but had to adjust to the environment.
This has analogy to the situation faced by ectotherms. The recognition that they widely conform to UTPCs suggests they mainly cope by interacting systems altering their rates in a coordinated fashion.
The situation changed for the precursors of mammals with the longer retention of embryos in the mother's body and development in a warmer and more stable environment. A somewhat analogous change has occurred in modern construction with more prefabrication and modular building. This has allowed for more varied and complicated designs.
I am sure modern planning has progressed well beyond simple critical paths. Completing many of the tasks in a single location means that sharing of components between tasks is now possible so the idea of a task as a single isolated activity no longer applies. Optimizing each task becomes more difficult because of this interaction. It might then happen that the project ends up with multiple critical (or sub-critical) paths, where even small mistakes can result in a faulty product.
This site seeks to examine where analogous events occurred for mammals, or particularly, the human lineage.