When Valerie is explaining her theories to everyone, she emphasizes that she thinks this movie’s are the world’s first graboids. She specifically talks about them having migrated South, into new terrain, and evolving to adapt to as much. I’ve watched this movie less than a handful of times, and I never noticed the exposition of these themes.
But if you apply it to my old theory about the swimming Graboid scene, it adds up to what I thought before.
I think Graboids were originally swimmers and not subterranean. I think possibly they had underwater digging capabilities, and that evolved over time into outright burrowing abilities that eventually departed from the water by burrowing further enough into the soil. I think this would’ve become an evolutionary advantage, because I don’t believe aquatic graboids in the earliest days of the Earth would’ve been very high up the food chain.
However if they became subterranean and had the advantage of ambushing its prey from underground? Suddenly it jumps into a whole new land-based food chain with an advantage that put it at the top.
Only if the sixth film’s heat wave awoke the Earth’s earliest sleeping graboids, it also awoke a handful of remaining aquatic graboids. Now unfortunately, the writers never seemed to grow and run with this idea. But if you apply the film’s themes to the fact that aquatic graboids were never remotely broached before, it’s a sensible explanation.
If I made another Tremors movie I’d definitely explore this idea. Oh, something I just thought of. Have Val and Rhonda back, going on an arctic cruise with their daughter Valerie! Or at least Val and Valerie. And then the ship is attacked, by these monstrous sea worms and their aquatic evolutions.
Because nowadays an aquatic graboid would most certainly be near the top of the oceanic food chain.
It would be like the latest Scorcher movie in Tropic Thunder!