Is comma needed before “and” in two connecting clauses?

Question

I have the fallowing sentence (I've changed the content to keep it fairly understandable, the relations between the parts are the same).

However, it states in the literature that green people love apples, which strengthens the idea that at least some green people would buy apples and that by opening a chain of apple stores great profits can be made.

I'm not sure if I should leave it as is, add a comma before the emphasized "and" or make the part after the "and" into a new sentence.

Answer 1

Between two independent clauses, a comma is common before and, but since these are both subordinate clauses attached to idea, I would avoid the comma, which suggests a separation that isn't there.

Answer 2

"Comma before and" is a style issue, which is frowned upon by certain style guides.

However, I personally encourage its judicious use to disambiguate and to improve readability.

In your example, the sentence in any case is too long and begs to be divided into smaller ones. The real issue here therefore, is not the comma.

Answer 3

Placing a comma after a conjunction is a style used by me and those whose styles I have imitated, to compel the reader to pause in expectation before continuing with reading the rest of the sentence.

To me the effect is like pulling the rubber band of the catapult back and then releasing it:

Not only did she destroy all the books in the library but, she even pointed her fingers at me implying that I had done it.

She was the brightest, the most charming star of the evening and, she was the sweetest angel I had ever met. And, her name is Betty White.