The “flat earth” meme comes from that plate tectonics is false. In general, continental drift has been explained with two models, one where the Earth radius has been static, and another where the radius has increased, and with expansion tectonics, you have all continents drifting apart simply because of an increase in radius. Since the dominant paradigm has been plate tectonics, which is a proto-science, that makes people confused.

It is very common that false models produce meme-branches like “flat earth”, and that specific memeplex can also be traced to the idea that gravity is an interaction between the mass of objects, a proto-science, as it is actually electromagnetic, which you can easily see with the Coriolis force, and of course, Newton pre-dates widespread knowledge about electricity.

I am interested in memetics, and like to see value in all information, and examples of “meme-branches” like the “flat earth” meme trend that are the result of false models, is Christianity, ideas that have mutated (still valuable information of course) because knowledge that our sun was in a binary with Sirius was lost, exactly because the sun-Sirius system approached its aphelion and Sirius size in the night sky decreased, because the distance increased.

References

On the Origin of Continents and Oceans: A Paradigm Shift in Understanding

The “Coriolis force” is electrical currents, as are waves in the ocean