There are several acceptable ways to separate independent clauses, but simply using a single comma by itself is not one of them. To do so creates an error known as the comma splice. The example sentence, by using a comma instead of a period, coordinating conjunction and a comma, or a semicolon, contains such an error.

This is an example of a comma splice. The two clauses here are both independent clauses, meaning each could stand on its own as a full sentence. Commas cannot be used to separate such clauses. A semicolon would be appropriate here. Another alternative would be to add a conjunction after the comma, such as "...attacked by piranhas, so he decided..."

The error in this sentence is that two independent clauses ("Laura wanted to attend her high school's ten-year reunion" and "it was only the possibility of seeing her ex-boyfriend that made her hesitate") are being joined by a comma, which is an incorrect use of a comma. Since independent clauses could be seperate sentences, there needs to be a stronger form of punctuation than a comma to join them, such a semicolon, a period, or a coordinating conjunction followed by a comma. 

When two independent clauses are joined only by a single comma, this results in an error known as a "comma splice." In the example above, the two independent clauses could be correctly connected by a semicolon or a comma followed by a conjunction (e.g. "and" or "but"). In addition, the two independent clauses could be made into distinct sentences.

The sentence given is an example of a comma splice. A comma cannot join together two independent clauses. The two clauses can be made into two separate sentences, or can be joined using a semicolon instead of a comma. 

Two independent clauses being joined only by a single comma result in an error known as the "comma splice." In the example above, a period, a comma and a conjunction, or a semicolon would all be appropriate to punctuate the sentence.

When two independent clauses are joined only by a single comma, this results in an error known as the "comma splice." Since both of the clauses in the example above are independent, they could stand on their own as full, grammatically complete sentences, a semicolon, period, or comma and a conjunction would be needed to properly punctuate the sentences (or compound sentence).

The example sentence attempts to create a compound sentence using only a comma, thus creating a comma splice. In the example above, something more than a comma is needed to separate the two clauses. 

This list is punctuated correctly. There should be a comma between each item in the list and an additional comma on either side of “Susanna,” which modifies “their sister.” (If “their sister, Susanna,” was the first or second item in the list, a semicolon would be needed to separate the items for clarity’s sake, but here it’s unnecessary.) In the second half of the sentence, a semicolon correctly separates the two independent clauses without a conjunction.

Here we have a comma splice: two independent clauses that are incorrectly separated by a comma. Two independent clauses in the same sentence must be punctuated by either a comma with a conjunction or a semicolon. Correctly punctuated, this sentence would read: “Although certainly the best known of the early aviators, Orville and Wilbur Wright were not the only inventors pioneering airplane designs; the Montgolfier brothers should also be remembered for their timely rediscovery of the hot-air balloon.” The comma after “aviators” is correct, since it’s separating an independent from a dependent clause.