|Alfred Lotka's 1922 "trigger action" model of animate form dynamics, according to which the light that causes the dynamite to explode operates via the same mechanism as when a gazelle "sights" a predator, which causes the explosive flee reaction.|
The origin of the concept of “trigger action”, being the general idea that “trigger” of a gun, when the hammer hits the powder, whereby kinetic energy of the impact causes the nitrogen-based products to combust or explode into products, which acts to release the stored energy of gun powder, so to propel or force the bullet into an accelerated motion, for the most part, is a concept invented by Alfred Lotka, namely an extrapolation of this model into the area of the evolution of animals, which originated in his learning of activation energy from the 1902 lectures of Wilhelm Ostwald, and presented by Lotka, in his reformulated view, in the 1920s.
Lotka, retrospectively, however, seems to think that the concept originated in 19th century French science; the following are his views:
“The significance of ‘trigger action’ seems to be have been first pointed out by Sadi Carnot [c.1825], and more specifically by Adhemar Venant (Ѻ), who speaks of it as ‘raised work’ (travail de decrochement), as in the pulling of a ‘trigger’ (declic). See Boussinesq, Cours de physique mathetnatique (Course in Physical Mathematics), Tome III, p. XXXII (in section: ‘Conciliation of Veritable Determinism with the Existence of Life and Moral Freedom’ ("Conciliation du veritable deterrninisme avec l'existence de la vie et de la liberte morale"). Paris, Gauthier-Villars, 1922, but referring to original publications in 1872, 1878.”— Alfred Lotka (1945), “The Law of Evolution as a Maximal Principle” (pg. 170)
“This observation, casually introduced by Ostwald in one of his lectures in 1902, was the ‘trigger’ that set off the train of thought developed in my subsequent publications, and summarized, in part, in my Elements of Physical Biology (1925) and Analytical Theory of Biological Associations (Theorie Analytique des Associations Biologiques) (1934, 1939).”— Alfred Lotka (1945), “The Law of Evolution as a Maximal Principle” (pg. 176)
In 1922, Alfred Lotka, publicly, began popularized the term "trigger action", based on the model of a gun, whereby the small amount of work done in the act of pulling the "trigger" releases a disproportionately larger amount of work in the firing of the projectile, according to which when a prey "sights" a predator, the "light" of the visual fear stimulus, triggers an explosive flee reaction, akin to the mallet of a gun triggering an explosion of gun powder.
The following is the stoichiometric equation for the detonation of nitroglycerin, the component of dynamite, which Lotka compares to the predator-prey reaction:
The considerable chemical energy of the detonation is due to the high strength of the bond in molecular nitrogen N2, i.e. a triple bond (N≡N).
Lotka seems to indicate, via footnote, that the term “trigger action” originates from a combination of his own writings (1912) along with those of French physician Hyacinthe Guilleminot (1919) and English biologist James Johnstone (1921). 
Following Lotka, others have used the term, including: Frederick Soddy (1926), and Richard Adams (1975) in attempts at thermodynamically explaining the standard definition of work, as in weight lifted through a height (or force times distance), in the context of biological work, e.g. the sight of a predator triggering a flee response, or human work, e.g. a workman operating a power-driven appliance at a factory. 
Adams defines trigger action, as that in which action in the form of information from one system triggering off a change of state in another system, whereby the change of state continues until the second system reaches another state of equilibrium. He also speaks of trigger mechanisms; which, he says, come in many kinds. 
1. Thims, Libb. (2007). Human Chemistry (Volume One) (trigger action, pg. 102). (preview), (Google books). Morrisville, NC: LuLu.
2. (a) Lotka, Alfred J. (1922). “Natural selection as a physical principle” [PDF]. Proc Natl Acad Sci, 8, pp 151–54.
(b) Soddy, F. (1926). Virtual Wealth and Debt - the Solution of the Economic Paradox (pg. 58). London: George Allen & Unwin LTD.
3. Adams, Richard N. (1975). Energy and Structure: a Theory of Social Power (pg. 119). University of Texas Press.
4. (a) Lotka, Alfred J. (1912). “Article”, J. Washington Acad. Sci., Vol. 2, pg. 71.
(b) Guilleminot, Hyacinthe. (1919). Matter and Life (La Matiere et la Vie) (pg. 115). Flammarion.
(c) Johnstone, J. (1921). The Mechanism of Life (pg. 49). Liverpool.