A cartoon schematic visualizing the effect of filaments on the morphological evolution of galaxies at early times in TNG50. The qualitative residual effect of filament density (after removing the mass dependence) on various morphological characteristics of galaxies at z ≳ 1, based on our results in Section 3, is shown by the sketch in the middle. To the left and right of this sketch, we illustrate the types of morphological phenomena associated with low- and high-density filaments, respectively. While many of these relationships disappear at z ≲ 1, some remain and some even reverse.