In the example: Some cultivars of corn are much more closely related morphologically to sorghum than to most other cultivars of corn.

I am seeing SOME CULTIVARS vs OTHER CULTIVARS and comparing to being more closely related to MORPHOLOGICALLY TO SORGHUM. I am not seeing : sorghum v. most other cultivars of corn.

After reading the comments, the instructor keeps using this example:

John is closer to Kate than to Mary.

What are the two things being compared? John vs. Mary? Or Kate vs. Mary?

I see it as this : Who is closer to KATE, John or Mary. John is closer to kate, John has shorter distance to Kate than Mary. JOHN vs MARY.

What are the triggers to seeing the comparison as Sorghum? I don't understand.