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Coastline Similarity

|< < Prev #3132 (August 22, 2025)

Title text: Hey! A bunch of the early Cretaceous fossils on each coast seem to have been plagiarized, too!

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Explanation

This comic depicts a classroom, likely relating to geography, geology or history, in which the teacher (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]}

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. 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 descendents 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.

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.")

Transcript

[Miss Lenhart is holding a pointer pointing to a wall map. The map shows South America and Africa, with the east coast of South America and the southwest coast of Africa highlighted in red.]

Miss Lenhart: People had long noticed that South America and Africa had similarly-shaped coastlines.

[A side view of the classroom. Jill and Cueball are sitting at school desks, looking at Miss Lenhart. The wall map is visible behind Miss Lenhart.]

Miss Lenhart: In the 20^th century, geologists finally found the explanation:

[The same scene, with Cueball having his hands on his face.]

Cueball: Plagiaris--

Miss Lenhart: Continental drift.

Cueball: Oh.

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