Implement an equivalent of the "macrosynteny index"

[charles-plessy]

https://pmc.ncbi.nlm.nih.gov/articles/PMC10615371/

This conservation index is calculated by counting the number of one-to-one orthologous gene pairs whose genes are in homologous chromosomes/scaffolds and dividing it by the number of one-to-one orthologs whose genes reside in non-homologous chromosomes/scaffolds3,5.

(Also find the primary paper for this index)

[charles-plessy]

https://pubmed.ncbi.nlm.nih.gov/23254933/ (supplemental material page 95)