This is the second part in a series talking to "Battlestar Galactica" co-producer and writer David Weddle. Part One can be found by clicking here.

It used to be that a good science-fiction show couldn’t even begin to be a good science-fiction show unless there was some kind of alien in it. Seriously, who would want to see a sci-fi show without some extra-terrestrial being?

In 2002, Joss Whedon broke the mold by saying his short-lived Fox series "Firefly" would have no aliens. While it did get some people talking, it was an idea that stayed popular when the new "Battlestar Galactica" took the air alien free.

Most of the explanation for that is because Cmdr. Adama’s Edward James Olmos made it clear if little green men showed up on the set, he would be gone. But does that really mean aliens won’t be making their way to the Galactica fleet?

"Battlestar Galactica" co-producer and writer David Weddle fessed up.

"I’m not going to promise you’ll never see an alien on our show," Weddle told SyFy Portal’s Michael Hinman. "But it will not be the rubber-headed humanoid types you see on Star Trek and countless other sci-fi shows. Edward James Olmos has said that if we ever resorted to that, he’d walk. I’m inclined to agree with him."

But ... wait a minute. Aliens or not?

"Rubber-headed humanoids aliens have always had a place in sci-fi and always will have a place," Weddle said. "I’m sure others will find inventive and revealing ways to utilize them. But because of Star Trek and shows of that ilk, they have become a cliche and we have challenged ourselves to create a compelling drama without have to resort to lizard men from deep space."

Without the staples of science-fiction like aliens, Weddle and the rest of the crew of "Battlestar Galactica" have to rely on other elements to make the show a success. And while writing plays a major role in such an endeavor, Weddle said it doesn’t stop there.

"I am amazed by our cast," he said. "Unlike other shows I have been on, there are no weak links. It makes writing for ’Battlestar’ considerably easier because even if your writing is below par, you know the actors will bring the scenes up to a whole new level — find new dimensions and nuances in the scenes.

"Sometimes they will challenge you, question their actions or motivations or dialogue in a scene. We writers may bitch and get irritated, but when we address their concerns, we usually have to admit they were right and that the material is improved. With out cast, it’s possible to write subtext lines in the script, such as, ’We see by the expression on Starbuck’s face that she’s heartbroken,’ and we [know] those actors can deliver it. You can read their thoughts and emotions in their faces without a single word of dialogue. That’s a rare and beautiful thing."

Of course, if there’s any discussion about dialogue, it has to be done through the amazing technology of telephones because believe it or not, writers like Weddle and his partner Brad Thompson are not a constant presence on the "Galactica" sets. It’s not that they don’t want to be there ... they just can’t.

"We are not on the sets very often because the show is shot in Vancouver, and we are here at Universal (in California) frantically hammering out future episodes," Weddle said. "We participate in preproduction meetings and cast table reads via conference calls and get storyboards on special effects sequences from Vancouver. We often do rewrites to accommodate ideas from the director or to address production problems."

But while they do spend a lot of time away form the set, Weddle said he and Brad find the time to be in Canada when they can.

"Brad went up to Vancouver last year for the production of ’The Hand of God,’ and (co-executive producer) Toni Graphia and I went there for the production of ’Colonial Day,’" Weddle said. "I love to go there when the schedule permits because you can become much more involved."

And like any on-site visit, there can be benefits.

"On ’Colonial Day,’ we went location scouting with the director and did rewrites to fit the locations," Weddle said. "You can’t do that nearly as well if you’re down in L.A. looking at pictures of the locations. Also, you get input from the actors. Katee Sackhoff told me, ’I would love it if Starbuck could wear a dress in the party at the end of the episode,’ I told Toni, and we immediately wrote it in. James Callis (Gaius Baltar) improvised his encounter with Playa (Christina Schild), the reporter, in the bathroom for Toni and I, and we immediately approved it.

"It’s electrifying to be there during shooting. I wish the schedule allowed us to do it more often."

Another element that makes "Galactica" the show not to miss on SciFi Channel’s Friday night schedule is its realism. Sure, the shaky documentary-style camera work can help create some realism, but it doesn’t work unless the audience feels that the actions of the characters make sense.

One of those scenes came in the second-season episode "Shattered," where Col. Tigh (Michael Hogan) had a very violent encounter with the exposed Cylon Sharon "Boomer" Valerii (Grace Park), that included Tigh punching Boomer in the face while she was imprisoned.

"We didn’t hear from any women’s groups over the Sharon interrogation scenes in ’Scattered,’ but we did hear from a number of Cylon Civil Rights Groups," Weddle said jokingly. "But since we don’t recognize Cylons as a legitimate lifeform, the Supreme Court refused to hear the case.

"In other words, the Sharon interrogation scenes are not in any way meant as a comment on gender roles or domestic abuse. They embody one of the main allegorical themes of the show, which is the tendency to dehumanize the enemy in times of war. This has been going on since the dawn of time. We convince ourselves that the enemy is somehow less than human, does not value life the way we do or share any of our common values. This enables us to rationalize and justify the terrible things we do to our enemies such as kill and torture them."

The Galactica Boomer met her death in a Jack Ruby-like assassination, but Weddle said not to expect an early exit by Park.

"Sharon is a crucial character because she forces several members of Galactica’s crew to confront the fact that the Cylons are more complex than they’d like to think, and full of the same passions and emotions that we have," Weddle said. "This could cause the whole edifice of rationalization that some of Galactica’s soldiers use to justify their actions to crumble like a house of cards. Or maybe not. I, for one, can’t wait to see how the Sharon-Tyrol-Helo-Adama story unfolds in future episodes."

"Battlestar Galactica" airs Fridays at 10 p.m. ET on SciFi Channel. In future installments of this interview, David Weddle delves more into the writing process, the genesis of some of the minor characters, and how "Battlestar Galactica" compares to other shows, like Star Trek.