During whole genome duplication, thousands of genes are duplicated, and many are lost. Among those that are retained, there is no obvious pattern to the genomic location of descendant paralogs. In a rare instance (teleost fasn2), the two descendant copies appear to have co-located to a chromosome with opposing direction of transcription (antisense) within ~3kb of each other:

https://useast.ensembl.org/Larimichthys_crocea/Location/View?db=core;g=ENSLCRG00005019318;r=XXIII:5576926-5591828;t=ENSLCRT00005052105

Synteny of fasn2 paralogs is conserved across taxa with a common ancestor >300mya. I am not familiar with plant or fungal genomes, but this is not a common occurrence in animal genomes. Can someone explain why ancient paralogs would migrate to a shared chromosomal locus, with synteny conserved for hundreds of millions of years?