xkcd.WTF!?

Explanation ➲

This comic depicts a classroom, likely relating to geography, geology or history, in which Miss Lenhart is discussing the similar coastlines of Africa and South America, and the way that modern understanding has revealed the cause. Cueball initially assumes that one coastline plagiarized the other before Miss Lenhart continues by revealing that it was continental drift that explained the similarity.

Continental drift is the widely accepted theory that Earth's continents were once all connected, and have been moving relative to each other due to plate tectonics. One of the clues that actually led to this discovery was that the shapes of the coastlines of South America and Africa that are separated by the Atlantic Ocean are similar. The similarity is much greater for the submerged continental shelves than for the visible coastlines; they're like adjacent pieces of a jigsaw puzzle.

Plagiarism is the act of claiming credit for another individual's work, usually by duplicating the results. The discovery of plagiarism in an already-renowned body of work is often cause for scandal, and Cueball's reaction to the assumed plagiarism of the African/South American coastlines reflects this. Of course, continents are inanimate objects, and have no concept of plagiarism, let alone know how to perform it^{[citation needed]}. It would take an extremely broad definition of plagiarism for this to count as such, based on neither continent giving "credit" to the other. That would apply equally well (or poorly) any time a thing was broken into pieces large enough that they could be fit back together. Many people have believed that the Earth was created by one or more entities, such as gods or heroes. Some regard the Earth as one or more living things. So the Earth, or one such creator could have copied portions of design.

The title text continues the joke about plagiarism. Additional corroborating evidence of continental drift is that there are similar species of plant and animal fossils on the two sides of the Atlantic, dating to the time when they were connected (which, contrary to Randall's claim, is actually the Triassic period, not the Cretaceous). Cueball thinks that the progenitors of these species also plagiarized each other, as opposed to the more mundane explanation which is that the progenitors were the same for both. The younger fossils are descendants of some species that existed across the once-connected lands, the older ones are the species that did not yet have the nascent Atlantic Ocean in their lives.

This is a very rare example where it is not Miss Lenhart that makes a joke as the teacher, but actually teaches the truth, and it is instead here one of her pupils that makes the joke (intentionally or not). A much more typical scenario for her teachings could for instance be seen in 1519: Venus.

The theory of continental drift was originally proposed by Alfred Wegener in 1912, based on such fossil evidence and other geological features common to the two continental borders, in addition to the similarities in shoreline shapes. It's significant to the history of science as a general subject, as a proposal that was originally met with strong opposition (not to mention mockery) but eventually became accepted by almost everyone. Modern cranks and crackpots sometimes point to it in support of their own implausible "theories", as though universal rejection of a "theory" by all of the experts somehow proves that it will someday be accepted and its originator proven right all along. In fact, Wegener's original theory did have a serious flaw, in that it lacked a plausible mechanism, though it was otherwise correct. Modern cranks' "theories" generally lack both plausible mechanisms and good analysis of supporting evidence. ("Yes, they laughed at Galileo... but they also laughed at Bozo the Clown.")

The title text of 2690: Cool S jokes about a milder version of plagiarism for the discovery of DNA, specifically copying off of the student in front of you.