On the next map the tick marks indicate the latitude - longitude grid. The map is based on world population given by five degree quadrilaterals, but uses only the marginal distribution of the population (population by latitude and population by longitude) hence it is a “pseudo” cartogram. Computer rendition using a program with an anamorphizing map projection.
W. Tobler, 1986, “Pseudo Cartograms”, The American Cartographer, 13(1):43-50.