May Kendall's delightfully satiric poem “The Lay of the Trilobite” first appeared in Punch magazine in 1885. To fully understand the poem, one must know something about its historical context.
During the latter half of the 1800s, social Darwinism was prominent. Using Darwin's theories of evolution, social Darwinists claimed that people in society are also subject to the “survival of the fittest.” Those who are strong and willing to fight tooth and nail to survive in society will triumph over those who are weak. According to such people, this was the “natural” order of things, and many used it to justify the oppression of the poor and the accumulation of wealth without social responsibility.
This is the kind of thing that Kendall is criticizing in her poem. The speaker looks upon the fossilized form of “an ancient trilobite” and thinks how wonderful it is to be a human being. Then, suddenly, the trilobite speaks, and according to this creature, being human is not so great after all. Humans think they have evolved as “shining lights / Of wisdom and perfection,” he remarks, yet they confuse each other with conflicting philosophies all the time. They conquer each other and force each other through violence to accept the dominant party's ways. They fight in politics as if they “were possessed,” and they wage war constantly, thinking that whoever makes the most noise must be in the right.
These are all qualities that point to the tenets of social Darwinism, an “evolution” gone wrong. In fact, the trilobite is quite happy to be without them. He “didn't grumble, didn't steal.” He merely lived, gently, freely, and without sorrow.
While the speaker doesn't respond to the trilobite, the creature's words strike a chord. Perhaps, the speaker wonders, human beings aren't quite so evolved as they think they are, or perhaps they have evolved in the wrong direction. Maybe, just maybe, if “evolution could / Have stopped a little quicker,” the speaker comments, people might have been much happier. The poet behind the speaker is suggesting that social Darwinism has “evolved” too far and certainly in the wrong direction.