War can be explained as hard-wired into people through evolution (a Darwinian struggle for survival), determined by cultural norms or triggered by ecological pressures.
Wilberforce had been briefed (or so it is generally assumed) by the ardent anti-Darwinian Richard Owen, who had been a guest in his home the night before.
Using plainspun humor as a brilliant counterpoint and never substituting cant for story, he sketches a world of Darwinian struggle where all the savages wear three-piece suits.