bumped to move the post to the top of the forum.

aditya.j wrote: Agricultural advances have substantially increased peruvian population growth, a demographic change that will have serious social implications. (note that there are actually 2 independent clauses connected with a comma)

Actually the second one is not a clause: a demographic change that will have serious social implications

a demographic change is a phrase and the rest of the words that will have serious social implications form a dependent clause modifying this phrase.

Let's see if I can clear things up .

First off, a comma splice occurs when two independent clauses are joined by only a comma (no accompanying FANBOYS or subordinating conjunction). In the following sentence, we have an independent clause joined to a dependent clause:

Agricultural advances have substantially increased peruvian population growth, a demographic change that will have serious social implications.

The bolded part is an independent clause. The non-bolded part is a dependent clause. Let's take a closer look at the latter:

A demographic change that will have serious social implications is composed of a subject, the relative pronoun 'that' and the relative clause. Nowhere is there a verb that connects to 'a demographic change.'

The original sentence is clearly an example of a summative modifier. It is important to note that a summative modifier does not connect two independent clauses. A summative modifier replaces what I call "the awkward which."

A decrease in the country's exports has hurt its GDP, which has caused the government considerable consternation.

A decrease in the country's exports has hurt its GDP, an occurrence that has caused the government considerable consternation.

In replacing 'which' with a word that captures the essence of the independent clause, I do not have an independent clause. Thus summative modifiers do not serve to join together independent clauses, but, with the help of a comma, connect the main clause to a dependent clause.

Hope that helps