If you’ve seen any of the Godzilla movies made over the years you know a couple of things for sure. Godzilla is big, like really big. Godzilla is scary and people lose their minds trying to get away from him so they don’t end up as lizard chow. Godzilla likes to knockdown tall buildings. But the questions remain, why is Godzilla so big? How did he get so big? And why is he knocking down these buildings?
Marine biologist Craig McClain had some insight into this:
Skyscraper height has increased dramatically over the last century. For Godzilla to continue to plow through buildings in major metropolises, a more formidable size is needed. Of course, this size change can only be evolutionarily adaptive if it changes the fitness of Godzilla, i.e. in the simplest case the number of offspring passed to the next generation. If Godzilla is able to topple buildings this might allow for greater acquisition of resources—in this case, food in the form of people. This would increase the lifespan of Godzilla [and] allow for more reproduction or allow for greater amount of energy to be passed to the offspring, increasing their rate of survival. Or perhaps toppling buildings is a sexual display that sexual partners cue on. Sexual selection!
On a side note, McClain calculates that Godzilla would produce 151,436,928 gallons of urine per day.
Imagine if Godzilla were only 50 meters tall in today world. You wouldn’t even see him until he turned down your street. Of course you’re here him and the destruction he causes, but that makes for a pretty boring movie.